thierry girard

GENERAL ANESTHESIA FOR CESAREAN SECTION

Thierry Girard

Dienstag, 27. März 2012

improvement occurred when data were collectedfrom 1991 to 1996. During that time period, there wasa decline in the case fatality rates for general anesthe-sia with improvement of the overall risk ratio betweengeneral and regional anesthesia. These advancescould be attributed to better anesthetic monitoringand published standards for anesthetic care. Pulseoximetry, capnography, and the Difficult AirwayAlgorithm18 are all examples of ASA practice im-provement efforts that have reduced deaths resultingfrom ventilation and intubation complications. Thecase fatality rates for general anesthesia continued todecrease from 1997 to 2002, and the relative risk ofgeneral compared with regional anesthesia fell to 1.7(95% confidence interval [CI] 0.6–4.6; P!.2), a non-significant difference. Of interest, two studies re-viewed failed intubations in obstetrics during 1993–199819 and 1999–2003.20 These studies revealedfailed intubation rates were 1:249 and 1:238, respec-tively, similar to the original 1:280 rate for failedintubation in obstetrics published in 1985,21 but therewere no maternal deaths in either recent series.

During the past two decades, anesthesiologistshave focused on improving their management ofdifficulty airway–failed intubation, gaining expertisewith the laryngeal mask and other airway devices. Incases of hemorrhage with hemodynamic instability orprolapse of the umbilical cord, general anesthesiamay be the most appropriate choice for cesareandelivery. The Maternal-Fetal Medicine Units Net-work quantified anesthesia-related complications as-sociated with cesarean delivery in 37,142 cesareandeliveries for singleton gestations.22 They reportedthat 93% of mothers received a regional anestheticwith a 3% failure rate and rare maternal morbidity.General anesthesia was more likely to be used (oddsratio [OR] 6.9) for cases when the decision-to-incisioninterval was less than 15 minutes or when ASA statuswas 4 or higher, that is, the most emergent cases andthe sickest patients. Improvements in case fatality ratefor general anesthesia are especially notable consid-

ering it is used for the highest risk patients and mosthurried emergencies. Our data suggest that generalanesthesia should not be avoided when necessarybecause the mortality rate is extremely low, only 6.5per million general anesthetics (Table 3). New guide-lines address appropriate recovery room manage-ment after general anesthesia and additional monitor-ing for obese patients at risk for sleep-obstructedbreathing because of concerns about complicationsoccurring during the postoperative period.23,24

Despite these encouraging reports demonstratingthe safety of general anesthesia for obstetrics, thereare new reports of increasing complications duringregional anesthesia. Although a recent description ofobstetric anesthesia liability claims by the ASAClosed Claims Project12 indicated that claims formaternal death and brain damage were decreasing,claims for nerve injury were increasing and are nowthe most common cause of litigation. In some casesthere were undetected intrathecal catheters and pro-viders were not always prepared to treat these emer-gencies. Four cases describe patients with cardiacarrest due to high block being transferred to anoperating room for resuscitation because there was noresuscitation equipment in the labor room. Similarly,the Doctors Insurance Company reported on 22anesthesia malpractice closed claims filed after mater-nal cardiac arrests on labor and delivery wards be-tween 1998 and 2006.25 Outcomes were poor: 10 of22 women died, 11 had anoxic brain damage, andonly one survived neurologically intact. Only onecase involved general anesthesia and failed intuba-tion. Thirteen cases were respiratory arrests afterepidurals or spinals. Eight followed labor epiduralplacement with unintentional subarachnoid block andfive occurred during spinal anesthetics for cesareandelivery. None of the operating room cases hadaudible alarms on the monitors at the time of arrest,making delay in response likely. In seven cases,resuscitation was delayed while the patient wasmoved to the operating room, either to facilitate

Table 3. Case Fatality Rates and Rate Ratios of Anesthesia-Related Deaths During Cesarean Delivery byType of Anesthesia in the United States, 1979–2002

Year of Death

Case Fatality Rates*

Rate RatiosGeneral Anesthetic Regional Anesthetic

1979–1984 20.0 8.6 2.3 (95% CI 1.9–2.9)1985–1990 32.3 1.9 16.7 (95% CI 12.9–21.8)1991–1996 16.8 2.5 6.7 (95% CI 3.0–14.9)1997–2002 6.5 3.8 1.7 (95% CI 0.6–4.6)

CI, confidence interval.* Deaths per million general or regional anesthetics.

VOL. 117, NO. 1, JANUARY 2011 Hawkins et al Anesthesia-Related Mortality in the United States 73

Obstetrics and Gynecology 2011; 117(1):69

Anesthesia-Related Maternal Mortality in theUnited States: 1979–2002Joy L. Hawkins, MD, Jeani Chang, MPH, Susan K. Palmer, MD, Charles P. Gibbs, MD,and William M. Callaghan, MD

OBJECTIVE: To examine 12 years of anesthesia-relatedmaternal deaths from 1991 to 2002 and compare themwith data from 1979 to 1990, to estimate trends inanesthesia-related maternal mortality over time, and tocompare the risks of general and regional anesthesiaduring cesarean delivery.

METHODS: The authors reviewed anesthesia-relatedmaternal deaths that occurred from 1991 to 2002. Type ofanesthesia involved, mode of delivery, and cause ofdeath were determined. Pregnancy-related mortality ra-tios, defined as pregnancy-related deaths due to anes-thesia per million live births were calculated. Case fatalityrates were estimated by applying a national estimate ofthe proportion of regional and general anesthetics to thenational cesarean delivery rate.

RESULTS: Eighty-six pregnancy-related deaths were as-sociated with complications of anesthesia, or 1.6% oftotal pregnancy-related deaths. Pregnancy-related mor-tality ratios for deaths related to anesthesia is 1.2 permillion live births for 1991–2002, a decrease of 59% from1979–1990. Deaths mostly occurred among youngerwomen, but the percentage of deaths among womenaged 35–39 years increased substantially. Deliverymethod could not be determined in 14%, but the remain-ing 86% were undergoing cesarean delivery. Case-fatality

rates for general anesthesia were 16.8 per million in1991–1996 and 6.5 per million in 1997–2002, and forregional anesthesia were 2.5 and 3.8 per million, respec-tively. The resulting risk ratio between the two tech-niques for 1997–2002 was 1.7 (confidence interval 0.6–4.6, P!.2).

CONCLUSION: Anesthetic-related maternal mortalitydecreased nearly 60% when data from 1979–1990 werecompared with data from 1991–2002. Although case-fatality rates for general anesthesia are falling, rates forregional anesthesia are rising.(Obstet Gynecol 2011;117:69–74)DOI: 10.1097/AOG.0b013e31820093a9

LEVEL OF EVIDENCE: II

The Division of Reproductive Health at the Centersfor Disease Control and Prevention (CDC) main-

tains surveillance data on pregnancy-related mortalityin the United States. They note that, although deathfrom complications of pregnancy has decreased by99% since 1900, there have been no further decreasesin the past two decades.1,2 Those at greatest risk intheir report were women of African-American race,women older than 34 years of age, and women whoreceived no prenatal care. Among women who diedafter a live birth, the leading causes of death wereembolism and hypertensive disorders of pregnancy.2,3

It has been estimated that 28–40% of maternal deathscould be prevented by changes in individual actionsor in system changes.4–6

In contrast to overall maternal mortality, anes-thetic causes of maternal mortality have progressivelydeclined and now account for less than 2% of preg-nancy-related maternal mortality in the UnitedStates.1,2 Obstetric anesthesiologists have used work-force surveys documenting how anesthetic care isprovided,7 practice guidelines with evidence-basedrecommendations for care,8 and international,9 na-tional,10 and state11 reviews of anesthesia-related ma-ternal mortality to improve patient safety. The Amer-

From the Department of Anesthesiology, University of Colorado School ofMedicine, Aurora, Colorado; the Centers for Disease Control and Prevention,Atlanta, Georgia; the Oregon Anesthesiology Group, Portland, Oregon; and theDepartment of Anesthesiology, University of Florida School of Medicine,Gainesville, Florida.

The authors thank the Centers for Disease Control and Prevention in Atlanta,Georgia, for allowing us to review their maternal mortality data for this study.The findings and conclusions in this report are those of the authors and do notnecessarily represent the official position of the Centers for Disease Control andPrevention.

Corresponding author: Joy L. Hawkins, MD, Department of Anesthesiology,12631 E. 17th Avenue, Mail Stop 8203, Aurora, CO 80045; e-mail:[email protected].

Financial DisclosureThe authors did not report any potential conflicts of interest.

© 2010 by The American College of Obstetricians and Gynecologists. Publishedby Lippincott Williams & Wilkins.ISSN: 0029-7844/10

VOL. 117, NO. 1, JANUARY 2011 OBSTETRICS & GYNECOLOGY 69


CONTROVERSIES cont.

Report of a debate held at the Society of Obstetric Anesthesia and Perinatology,40th Annual Meeting, Chicago, USA, May 2008

General anesthesia is unacceptable for elective cesarean section

Proposer: C.A. WongDepartment of Anesthesiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA

The Oxford English Dictionary defines ‘‘acceptable’’as capable, worthy, or likely to be accepted or gladlyreceived; hence, pleasing, agreeable, gratifying, or wel-come.1 Therefore, ‘‘unacceptable’’ means not capable,worthy, or likely to be accepted or gladly received; notpleasing, agreeable, gratifying, or welcome. Of course,cesarean deliveries can be performed under either neur-axial or general anesthesia. However, for most electivedeliveries, and many urgent deliveries, general anesthe-sia is not acceptable for cesarean delivery. There arebenefits to the mother of neuraxial anesthesia and signif-icant risks associated with general anesthesia. Similarly,there are benefits to the neonate of neuraxial anesthesiaand risks of general anesthesia. Generally, the benefits ofneuraxial anesthesia outweigh the risks, and the risks ofgeneral anesthesia outweigh the benefits. This discussionwill review these risks and benefits.

Risks of general anesthesia / benefits ofneuraxial anesthesia to the mother

Mortality: Obstetrical mortality data2 and closed-claimsdata from the American Society of Anesthesiologists(ASA) Closed-Claims Project3,4 show that the risk ofanesthesia-associated maternal mortality is higher inwomen who receive general anesthesia than in thosewho receive neuraxial anesthesia, although recent mor-tality data from the US indicate that this gap is narrow-ing.5 There are several limitations to these data. They donot specifically address elective vs. non-elective deliver-ies and denominator data are missing from these studies.However, given that the overall rate of neuraxial anes-thesia is significantly higher than general anesthesia,these data suggest that the risk of maternal mortality

associated with general anesthesia is higher than withneuraxial anesthesia.

Airway disaster/pulmonary aspiration: Airway disas-ters are the leading cause of anesthesia-associatedmaternal morbidity.2,4,6 The risk of failed intubation ishigher by an order of magnitude in pregnant womenthan in the general surgical population.7–9 Additionally,because of an increased metabolic rate and decreasedfunctional residual capacity (FRC), pregnant womenhave reduced tolerance for apnea and hence becomehypoxemic faster after failed intubation. In a computersimulation of apnea after 99% complete denitrogena-tion, the SaO2 decreased to <90% in 4 min 52 s in preg-nant vs. 7 min 25 s in non-pregnant women.10 Therefore,the total time available to secure the airway in pregnantwomen is significantly less than in non-pregnantpatients.

Pregnant women are assumed to be at higher riskfor pulmonary aspiration because of anatomic andhormonal changes that increase the risk of gastroesoph-ageal reflux. Pulmonary aspiration is frequently associ-ated with difficulty with airway management.4 Patientswith a full stomach undergoing general anesthesia donot aspirate if the trachea is intubated with a cuffedendotracheal tube quickly and smoothly. However, theneed for airway manipulation such as mask ventilationbecause of failed intubation, is associated with anincreased risk of aspiration. Avoidance of generalanesthesia decreases, although does not totally elimi-nate, the need for airway management.

Intraoperative awareness: The incidence of intraoper-ative awareness appears to be higher in the obstetricpopulation than the general population.11–13 Anesthesi-ologists frequently limit the dose of a volatile anestheticagent to less than 0.5 MAC (sevoflurane <1%) becauseof fear of neonatal depression and postpartum uterineatony and hemorrhage (vide infra). This practice maylead to an increased risk of awareness.13 Maintenanceof general anesthesia with 0.5 MAC sevoflurane in50% nitrous oxide is associated with a significant rate

Accepted October 2009Correspondence to: Cynthia A. Wong, MD, Department of Anesthe-siology, Northwestern University Feinberg School of Medicine, 251 E.Huron St., F5-704, Chicago, IL 60611, USA. Tel.: +1 312 472 3585;fax: +1 312 472 3590.E-mail address: [email protected]

International Journal of Obstetric Anesthesia (2010) 19, 209–217

www.obstetanesthesia.com

22. Carvalho B, Cohen SE, Lipman SS, Fuller A, Mathusamy AD,Macario A. Patient preferences for anesthesia outcomes associatedwith cesarean delivery. Anesth Analg 2005;101:1182–97.

23. Cohen SE, Subak LL, Brose WG, Halpern J. Analgesia aftercesarean delivery: patient evaluations and costs of five opioidtechniques. Reg Anesth 1991;16:141–9.

24. Harrison DM, Sinatra R, Morgese L, Chung JH. Epiduralnarcotic and patient-controlled analgesia for post-cesarean sectionpain relief. Anesthesiology 1988;68:454–7.

25. Yarnell RW, Polis T, Reid GN, Murphy IL, Penning JP. Patient-controlled analgesia with epidural meperidine after elective cesar-ean section. Reg Anesth 1992;17:329–33.

26. Cohen SE, Woods WA. The role of epidural morphine in thepostcesarean patient: efficacy and effects on bonding. Anesthesi-ology 1983;58:500–4.

27. Roseag OP, Lui ACP, Cicutti NJ, Bragg PR, Crossan M, KrepskiB. Peri-operative multi-modal pain therapy for caesarean section:analgesia and fitness for discharge. Can J Anaesth 1997;44:803–9.

28. Nikolajsen L, Sorensen HC, Jensen TS, Kehlet H. Chronic painfollowing caesarean section. Acta Anaesthesiol Scand 2004;48:111–6.

29. Eisenach JC, Pan PH, Smiley R, Lavand’homme P, Landau R,Houle TT. Severity of acute pain after childbirth, but not type ofdelivery, predicts persistent pain and postpartum depression. Pain2008;140:87–94.

30. Clark SL, Belfort MA, Dildy GA, Herbst MA, Meyers JA,Hankins GD. Maternal death in the 21st century: causes,prevention, and relationship to cesarean delivery. Am J ObstetGynecol 2008;199:36 e1–5.

31. Lewis G, editor. Confidential enquiry into maternal and child health(CEMACH). Saving mothers’ lives: reviewing materal deaths tomake motherhood safer – 2003–2005. London: CEMACH; 2007.

32. Rodgers A, Walker N, Schug S, et al. Reduction of postopera-tive mortality and morbidity with epidural or spinal anaesthe-sia: results from overview of randomised trials. BMJ 2000;321: 1493.

33. Roderick P, Ferris G, Wilson K, et al. Towards evidence-basedguidelines for the prevention of venous thromboembolism:

systematic reviews of mechanical methods, oral anticoagulation,dextran and regional anaesthesia as thromboprophylaxis. HealthTechnol Assess 2005;9:iii–iv, ix–x, 1–78.

34. Brandsborg B, Nikolajsen L, Hansen CT, Kehlet H, Jensen TS.Risk factors for chronic pain after hysterectomy: a nationwidequestionnaire and database study. Anesthesiology 2007;106:1003–12.

35. Reynolds F, Seed PT. Anaesthesia for caesarean section andneonatal acid-base status: a meta-analysis. Anaesthesia 2005;60:636–53.

36. Lee A, Ngan Kee WD, Gin T. A quantitative, systematic review ofrandomized controlled trials of ephedrine versus phenylephrine forthe management of hypotension during spinal anesthesia forcesarean delivery. Anesth Analg 2002;94:920–6.

37. Lie B, Juul J. Effect of epidural vs. general anesthesia onbreastfeeding. Acta Obstet Gynecol Scand 1988;67:207–9.

38. Camann W. Labor analgesia and breast feeding: avoid parenteralnarcotics and provide lactation support. Int J Obstet Anesth2007;16:199–201.

39. Thomson AJ, Webb DJ, Maxwell SR, Grant IS. Oxygen therapyin acute medical care. BMJ 2002;324:1406–7.

40. Tan A, Schulze A, O’Donnell CP, Davis PG. Air versus oxygen forresuscitation of infants at birth. Cochrane Database Syst Rev2005:CD002273.

41. Khaw KS, Wang CC, Ngan Kee WD, Pang CP, Rogers MS.Effects of high inspired oxygen fraction during elective caesareansection under spinal anaesthesia on maternal and fetal oxygena-tion and lipid peroxidation. Br J Anaesth 2002;88:18–23.

42. Perouansky M. General anesthetics and long-term neurotoxicity.Modern anesthetics: handbook of experimental pharmacology. Ber-lin: Springer; 2008. p. 143–57.

43. Mellon RD, Simone AF, Rappaport BA. Use of anesthetic agentsin neonates and young children. Anesth Analg 2007;104:509–20.

0959-289X/$ - see front matter!c 2009 Elsevier Ltd. All rights reserved.doi:10.1016/j.ijoa.2009.10.002

Opposer: Felicity ReynoldsSt Thomas’ Hospital, London, UK

I would not for one moment deny that regional anesthe-sia is superior to general anesthesia for elective cesareansection. It is not only preferable as an experience for themother who wishes to witness the birth of her baby andto share the experience with her partner, it is also saferin many respects. But this does not imply that generalanesthesia is unacceptable. Such an idea must be a hang-over from times when techniques were used that would,today, certainly be regarded as unacceptable. They were,by modern standards, downright dangerous and are lar-gely responsible for creating a climate of fear aroundgeneral anesthesia in obstetrics.

Historical perspective

Yes, techniques long abandoned would nowadays be re-garded as unacceptable. When in 1961 I first anesthe-

tized obstetric patients, cesarean section was rare, andmost patients needed our services for forceps delivery,retained placenta, vaginal delivery of the after-cominghead or the second twin. For breech or second twinone was usually presented with a woman already inthe lithotomy position, and a certain urgency. Thereceived procedure was to give ‘‘a quick whiff’’ ofcyclopropane – wonderfully swift and effective! Forthe rest, slightly more conventional general anesthesiawas the norm, although cricoids pressure, first describedonly in 1961,1 came into general use later. To avoid aspi-ration of gastric contents, we were taught to inducepatients either in the steep head-up position, in the hopethat refluxed gastric contents would not rise up as far asthe pharynx, or in the left lateral head-down position, sothat gastric contents would trickle out of the mouth andnot be inhaled. In the first six months of training wewere told not to attempt intubation if on our own, aswe might find it difficult, but rather to use maskAccepted October 2009

E-mail address: [email protected]

212 Controversies


22. Carvalho B, Cohen SE, Lipman SS, Fuller A, Mathusamy AD,Macario A. Patient preferences for anesthesia outcomes associatedwith cesarean delivery. Anesth Analg 2005;101:1182–97.

23. Cohen SE, Subak LL, Brose WG, Halpern J. Analgesia aftercesarean delivery: patient evaluations and costs of five opioidtechniques. Reg Anesth 1991;16:141–9.

24. Harrison DM, Sinatra R, Morgese L, Chung JH. Epiduralnarcotic and patient-controlled analgesia for post-cesarean sectionpain relief. Anesthesiology 1988;68:454–7.

25. Yarnell RW, Polis T, Reid GN, Murphy IL, Penning JP. Patient-controlled analgesia with epidural meperidine after elective cesar-ean section. Reg Anesth 1992;17:329–33.

26. Cohen SE, Woods WA. The role of epidural morphine in thepostcesarean patient: efficacy and effects on bonding. Anesthesi-ology 1983;58:500–4.

27. Roseag OP, Lui ACP, Cicutti NJ, Bragg PR, Crossan M, KrepskiB. Peri-operative multi-modal pain therapy for caesarean section:analgesia and fitness for discharge. Can J Anaesth 1997;44:803–9.

28. Nikolajsen L, Sorensen HC, Jensen TS, Kehlet H. Chronic painfollowing caesarean section. Acta Anaesthesiol Scand 2004;48:111–6.

29. Eisenach JC, Pan PH, Smiley R, Lavand’homme P, Landau R,Houle TT. Severity of acute pain after childbirth, but not type ofdelivery, predicts persistent pain and postpartum depression. Pain2008;140:87–94.

30. Clark SL, Belfort MA, Dildy GA, Herbst MA, Meyers JA,Hankins GD. Maternal death in the 21st century: causes,prevention, and relationship to cesarean delivery. Am J ObstetGynecol 2008;199:36 e1–5.

31. Lewis G, editor. Confidential enquiry into maternal and child health(CEMACH). Saving mothers’ lives: reviewing materal deaths tomake motherhood safer – 2003–2005. London: CEMACH; 2007.

32. Rodgers A, Walker N, Schug S, et al. Reduction of postopera-tive mortality and morbidity with epidural or spinal anaesthe-sia: results from overview of randomised trials. BMJ 2000;321: 1493.

33. Roderick P, Ferris G, Wilson K, et al. Towards evidence-basedguidelines for the prevention of venous thromboembolism:

systematic reviews of mechanical methods, oral anticoagulation,dextran and regional anaesthesia as thromboprophylaxis. HealthTechnol Assess 2005;9:iii–iv, ix–x, 1–78.

34. Brandsborg B, Nikolajsen L, Hansen CT, Kehlet H, Jensen TS.Risk factors for chronic pain after hysterectomy: a nationwidequestionnaire and database study. Anesthesiology 2007;106:1003–12.

35. Reynolds F, Seed PT. Anaesthesia for caesarean section andneonatal acid-base status: a meta-analysis. Anaesthesia 2005;60:636–53.

36. Lee A, Ngan Kee WD, Gin T. A quantitative, systematic review ofrandomized controlled trials of ephedrine versus phenylephrine forthe management of hypotension during spinal anesthesia forcesarean delivery. Anesth Analg 2002;94:920–6.

37. Lie B, Juul J. Effect of epidural vs. general anesthesia onbreastfeeding. Acta Obstet Gynecol Scand 1988;67:207–9.

38. Camann W. Labor analgesia and breast feeding: avoid parenteralnarcotics and provide lactation support. Int J Obstet Anesth2007;16:199–201.

39. Thomson AJ, Webb DJ, Maxwell SR, Grant IS. Oxygen therapyin acute medical care. BMJ 2002;324:1406–7.

40. Tan A, Schulze A, O’Donnell CP, Davis PG. Air versus oxygen forresuscitation of infants at birth. Cochrane Database Syst Rev2005:CD002273.

41. Khaw KS, Wang CC, Ngan Kee WD, Pang CP, Rogers MS.Effects of high inspired oxygen fraction during elective caesareansection under spinal anaesthesia on maternal and fetal oxygena-tion and lipid peroxidation. Br J Anaesth 2002;88:18–23.

42. Perouansky M. General anesthetics and long-term neurotoxicity.Modern anesthetics: handbook of experimental pharmacology. Ber-lin: Springer; 2008. p. 143–57.

43. Mellon RD, Simone AF, Rappaport BA. Use of anesthetic agentsin neonates and young children. Anesth Analg 2007;104:509–20.

0959-289X/$ - see front matter!c 2009 Elsevier Ltd. All rights reserved.doi:10.1016/j.ijoa.2009.10.002

Opposer: Felicity ReynoldsSt Thomas’ Hospital, London, UK

I would not for one moment deny that regional anesthe-sia is superior to general anesthesia for elective cesareansection. It is not only preferable as an experience for themother who wishes to witness the birth of her baby andto share the experience with her partner, it is also saferin many respects. But this does not imply that generalanesthesia is unacceptable. Such an idea must be a hang-over from times when techniques were used that would,today, certainly be regarded as unacceptable. They were,by modern standards, downright dangerous and are lar-gely responsible for creating a climate of fear aroundgeneral anesthesia in obstetrics.

Historical perspective

Yes, techniques long abandoned would nowadays be re-garded as unacceptable. When in 1961 I first anesthe-

tized obstetric patients, cesarean section was rare, andmost patients needed our services for forceps delivery,retained placenta, vaginal delivery of the after-cominghead or the second twin. For breech or second twinone was usually presented with a woman already inthe lithotomy position, and a certain urgency. Thereceived procedure was to give ‘‘a quick whiff’’ ofcyclopropane – wonderfully swift and effective! Forthe rest, slightly more conventional general anesthesiawas the norm, although cricoids pressure, first describedonly in 1961,1 came into general use later. To avoid aspi-ration of gastric contents, we were taught to inducepatients either in the steep head-up position, in the hopethat refluxed gastric contents would not rise up as far asthe pharynx, or in the left lateral head-down position, sothat gastric contents would trickle out of the mouth andnot be inhaled. In the first six months of training wewere told not to attempt intubation if on our own, aswe might find it difficult, but rather to use maskAccepted October 2009

E-mail address: [email protected]

212 Controversies


ORIGINAL ARTICLE

General anesthesia for cesarean delivery at a tertiary carehospital from 2000 to 2005: a retrospective analysis and10-year update

A. Palanisamy, A.A. Mitani, L.C. TsenDepartment of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women’s Hospital,Harvard Medical School, Boston, MA, USA

ABSTRACTBackground: Complications from general anesthesia for cesarean delivery are a leading cause of anesthesia-related mortality. As aconsequence, the overall use of general anesthesia in this setting is becoming less common. The impact and implications of thistrend are considered in relation to a similar study performed at our institution 10 years ago.Methods: The hospital database for all cesarean deliveries performed during six calendar years (January 1, 2000 through Decem-ber 31, 2005) was reviewed. The medical records of all parturients who received general anesthesia were examined to collect per-sonal details and data pertinent to the indications for cesarean delivery and general anesthesia, mode of airway management andassociated anesthetic complications.Results: Cesarean deliveries accounted for 23.65% to 31.51% of an annual total ranging from 8543 to 10091 deliveries. The per-centage of cases performed under general anesthesia ranged from 0.5% to 1%. A perceived lack of time for neuraxial anesthesiaaccounted for more than half of the general anesthesia cases each year, with maternal factors accounting for 11.1% to 42.9%. Fail-ures of neuraxial techniques accounted for less than 4% of the general anesthesia cases. There was only one case of difficult intu-bation and no anesthesia-related mortality was recorded.Conclusion: The use of general anesthesia for cesarean delivery is low and declining. These trends may reflect the early and increas-ing use of neuraxial techniques, particularly in parturients with co-existing morbidities. A significant reduction in exposure oftrainees to obstetric general anesthesia has been observed.

!c 2010 Elsevier Ltd. All rights reserved.

Keywords: General anesthesia; Cesarean delivery; Cesarean section; Neuraxial techniques; Regional techniques; Difficult airway;Airway management; Obstetrics

Introduction

The widespread adoption of neuraxial techniques for la-bor analgesia and cesarean delivery anesthesia has beenprompted by a number of benefits and concerns, includ-ing a desire to avoid the potentially difficult maternalairway and the risk of pulmonary aspiration.1–3 In addi-tion, recent population-based evidence indicates thatneuraxial anesthesia might be associated with a lowerincidence of adverse neonatal outcomes and learningdisabilities in children.4,5 It has also been associated withshorter hospital stays following cesarean delivery.6

Despite these findings, a recent meta-analysis failedto confirm an advantage with the use of neuraxial tech-niques versus general anesthesia (GA) in major maternalor neonatal outcomes.7 Moreover, GA remains a neces-sary choice, particularly when there is a perceived lackof time, a contraindication or refusal of neuraxial tech-niques. With fewer cesarean deliveries being performedunder GA, there is a growing concern that anesthesiaproviders, particularly those in training, will have littleor no opportunities to learn and maintain critical skillsfor maternal airway management.8–10 Although ad-vances in anesthetic pharmacology and airway equip-ment have made such airway manipulations safer, theoverall impact on clinical obstetric anesthetic practicehas yet to be determined.

In an effort to assess the indications and implicationsof GA use for cesarean delivery, we evaluated andreported data from our large volume, tertiary care insti-tution during the period of 1990 to 1995.10 The purpose

Accepted July 2010Correspondence to: Lawrence C. Tsen, MD, Department of Anesthe-siology, Perioperative and Pain Medicine, Brigham and Women’sHospital, Harvard Medical School, 75 Francis Street, CWN-L1,Boston, MA 02115, USA.E-mail address: [email protected]

International Journal of Obstetric Anesthesia (2011) 20, 10–160959-289X/$ - see front matter !c 2010 Elsevier Ltd. All rights reserved.doi:10.1016/j.ijoa.2010.07.002



of this analysis from the same institution for the period2000 to 2005, exactly one decade later, was to examinethe elements responsible for the administration of GAin cesarean delivery patients, investigate potential trendsduring the study period, and analyze changes in practicebetween the two time epochs where data were available.

Methods

After Hospital Research Office/Institutional ReviewBoard approval, the obstetric database at our institutionwas examined to determine the number of cesareandeliveries, both elective and emergent, and the type ofanesthesia provided during six calendar years (January1, 2000 through December 31, 2005). The medicalrecords of all parturients who received general anesthe-sia were subsequently examined to collect personaldetails and data pertinent to the indications for cesareandelivery, indications for GA, mode of airway manage-ment and associated anesthetic complications. The timeof administration of GA was recorded and subsequentlyallocated into one of two time shifts: 7:00 am to 3:00 pmand 3:00 pm to 7:00 am in accordance with prevailingwork-shift designations and resource availability. Theresults were compared to similar data collected duringsix earlier calendar years (January 1, 1990 throughDecember 31, 1995), which were reported previously.10

Data were analyzed using Chi-square or Fisher’s exacttest as appropriate with P < 0.05 accorded statisticalsignificance.

Results

In the study years 2000 to 2005, the annual number ofdeliveries ranged from 8543 to 10091 (Table 1). The per-

centage of cesarean deliveries varied from 23.7% to31.5%, with a progressive increase occurring in each sub-sequent year. Although the total number of deliveries re-mained relatively stable, the range of cesarean deliveryrates was higher in the current, versus previous, study(23.7–31.5% vs. 21.2–23.7%; P < 0.001). Despite the in-creased number of cesarean deliveries, the average rateof administration of GA declined dramatically to alow of 0.6% from 4.5% (previous study; P < 0.001) withthe majority being associated with emergency cesareandelivery (85.7%; Table 2).

The main indication for GA in all years was a per-ceived lack of time for neuraxial anesthesia, accountingfor at least 50% of the cases each year (Table 3). Mater-nal contraindications to neuraxial anesthesia were thenext major factor, comprising 28.6% of all cases. Fail-ures of neuraxial techniques necessitating GA werefew, consistently representing a range of 0–4% of cases.Among neuraxial techniques, there was only a singleCSE failure that required GA during the entire studyperiod. No specific trends could be discerned when neur-axial anesthesia failures were individually analyzed.

Analysis of indications for cesarean deliveriesrequiring GA demonstrated that true emergencies(non-reassuring fetal heart rate/bradycardia, placentalabruption/previa and cord prolapse) were associatedwith 40% to 68.4% of all cases (Table 4). Maternal fac-tors (preeclampsia, co-existing disease, failure to pro-gress, previous cesarean delivery etc) were responsiblefor GA at rates ranging from 11.1% to 42.9%. Amongmaternal diseases, the continuum of severe preeclamp-sia, HELLP (hemolysis, elevated liver enzymes, andlow platelets) syndrome and eclampsia was responsiblefor majority of GA administered (Table 5). Isolatedhematological, neurological and cardiac diseases were

Table 1 Total number of all deliveries, cesarean deliveries (%), those cesarean deliveries that required generalanesthesia (GA) and GA a percentage of the total number of cesarean deliveries

Year Total deliveries Cesarean deliveries Cesarean delivery rate (%) Cesarean deliveries requiring GA GA rate (%)

2000 9890 2339 23.7 24 1.02001 10091 2507 24.8 10 0.42002 10065 2579 25.6 9 0.42003 9444 2695 28.5 14 0.52004 8904 2656 29.8 19 0.72005 8543 2692 31.5 22 0.8

Table 2 Urgency of cesarean delivery by year with those that required general anesthesia according to the degree ofemergency

Cesarean deliveries 2000 2001 2002 2003 2004 2005 Average rate

Total 24 10 9 14 19 22Elective 2 (8.3%) 3 (30%) 3 (33.3%) 3 (21.4%) 0 3 (13.6%) 14.3%Emergent 22 (91.7%) 7 (70%) 6 (66.7%) 11 (78.6%) 19 (100%) 19 (86.4%) 85.7%

A. Palanisamy et al. 11


EDITORIALS

The obstetric airway: things are seldom as they seem

M. Joanne Douglas, MD • Roanne L. Preston, MD

Published online: 1 April 2011! Canadian Anesthesiologists’ Society 2011

‘‘Things are seldom what they seem,

Skim milk masquerades as cream…’’Gilbert and Sullivan, H.M.S. Pinafore

For decades, the obstetric airway struck fear in the heart of

the anesthesiologist as the incidence of failed intubation in

obstetrics was reported as 1:250 to 1:300, approximatelyten times more frequent than in the general surgical pop-

ulation.1,2 In spite of our fancy airway tools, algorithms,

and difficult airway workshops, a recently publishedexperience of more than 1,000 obstetric general anesthetics

(GA) suggested we had not made progress in this area: the

reported incidence of failed intubation was 1:250, anddifficult intubation occurred in 3.3% of cases.3

So, it is with some relief that one reads the article by

McKeen et al. in which they report their experience withthe maternal airway over a 20-yr period at a Canadian

academic tertiary care hospital.4 In 2,633 GAs, the inci-

dence of failed intubation was 1:1,300, similar to that of thegeneral surgical population, and difficult intubation was

encountered in 4.7%, which is at the lower end of the

reported range of 1.3% to 16.3% in obstetrics.3,5 Does thisstudy refute the widely held belief that intubation is more

difficult in the obstetric patient? In other words, do the

results reflect the complete picture, or are they a case of‘‘things are seldom what they seem’’?

The reasons for the apparent difficulty in managing the

obstetric airway are both clear and unclear. Undoubtedly,there are anatomic and physiologic changes in pregnancy

that make the airway of the term pregnant woman more

likely to present a less-than-ideal view for intubation.Nevertheless, one would think we would have found

solutions to manage the pregnant airway given the many

alternatives to direct laryngoscopy, the development ofobstetric-specific airway algorithms and associated training

drills6 and efforts to ensure junior trainees are supervised

when providing GA.It is our view that there remains more to the story than

solely the anatomical and physiological changes to the

maternal airway – these factors could be overcome by theuse of other airway devices. Other issues, e.g., the envi-

ronment in which we provide GA in obstetrics, are moredominant and more difficult to tackle. General anesthesia

usually is administered for an obstetric emergency, and

under these circumstances, the available anesthesia assis-tance is less skilled, the atmosphere is tense, the time

pressure is extreme (unlike anything else we face, other

than perhaps a nasty trauma case), and our proclivity is tobehave differently than we normally would for anesthesia

in a high-risk patient. It is our view that the situational

arena is probably the greatest key to our success or failurein managing the airway.

Compounding the problem is the fact that the GA rate in

obstetrics is only 5% to 7% in most tertiary care academiccentres.7 Consequently, a staff anesthesiologist may per-

form only five to ten GAs per year on average, resident

trainees may perform even fewer, and nursing assistance,relied on by most units, may be turned to for only one GA

per year. We have become so expert at providing neuraxial

anesthesia that our experience in providing GA in obstet-rics has diminished markedly.

M. J. Douglas, MD ! R. L. Preston, MDDepartment of Anesthesiology, Pharmacology and Therapeutics,University of British Columbia, Vancouver, BC, Canada

M. J. Douglas, MD (&)Department of Anesthesia, BC Women’s Hospital, Rm 1Q72,4500 Oak Street, Vancouver, BC V6H 3N1, Canadae-mail: [email protected]

123

Can J Anesth/J Can Anesth (2011) 58:494–498

DOI 10.1007/s12630-011-9492-8

EDITORIALS

The obstetric airway: things are seldom as they seem

M. Joanne Douglas, MD • Roanne L. Preston, MD

Published online: 1 April 2011! Canadian Anesthesiologists’ Society 2011

‘‘Things are seldom what they seem,

Skim milk masquerades as cream…’’Gilbert and Sullivan, H.M.S. Pinafore

For decades, the obstetric airway struck fear in the heart of

the anesthesiologist as the incidence of failed intubation in

obstetrics was reported as 1:250 to 1:300, approximatelyten times more frequent than in the general surgical pop-

ulation.1,2 In spite of our fancy airway tools, algorithms,

and difficult airway workshops, a recently publishedexperience of more than 1,000 obstetric general anesthetics

(GA) suggested we had not made progress in this area: the

reported incidence of failed intubation was 1:250, anddifficult intubation occurred in 3.3% of cases.3

So, it is with some relief that one reads the article by

McKeen et al. in which they report their experience withthe maternal airway over a 20-yr period at a Canadian

academic tertiary care hospital.4 In 2,633 GAs, the inci-

dence of failed intubation was 1:1,300, similar to that of thegeneral surgical population, and difficult intubation was

encountered in 4.7%, which is at the lower end of the

reported range of 1.3% to 16.3% in obstetrics.3,5 Does thisstudy refute the widely held belief that intubation is more

difficult in the obstetric patient? In other words, do the

results reflect the complete picture, or are they a case of‘‘things are seldom what they seem’’?

The reasons for the apparent difficulty in managing the

obstetric airway are both clear and unclear. Undoubtedly,there are anatomic and physiologic changes in pregnancy

that make the airway of the term pregnant woman more

likely to present a less-than-ideal view for intubation.Nevertheless, one would think we would have found

solutions to manage the pregnant airway given the many

alternatives to direct laryngoscopy, the development ofobstetric-specific airway algorithms and associated training

drills6 and efforts to ensure junior trainees are supervised

when providing GA.It is our view that there remains more to the story than

solely the anatomical and physiological changes to the

maternal airway – these factors could be overcome by theuse of other airway devices. Other issues, e.g., the envi-

ronment in which we provide GA in obstetrics, are moredominant and more difficult to tackle. General anesthesia

usually is administered for an obstetric emergency, and

under these circumstances, the available anesthesia assis-tance is less skilled, the atmosphere is tense, the time

pressure is extreme (unlike anything else we face, other

than perhaps a nasty trauma case), and our proclivity is tobehave differently than we normally would for anesthesia

in a high-risk patient. It is our view that the situational

arena is probably the greatest key to our success or failurein managing the airway.

Compounding the problem is the fact that the GA rate in

obstetrics is only 5% to 7% in most tertiary care academiccentres.7 Consequently, a staff anesthesiologist may per-

form only five to ten GAs per year on average, resident

trainees may perform even fewer, and nursing assistance,relied on by most units, may be turned to for only one GA

per year. We have become so expert at providing neuraxial

anesthesia that our experience in providing GA in obstet-rics has diminished markedly.

M. J. Douglas, MD ! R. L. Preston, MDDepartment of Anesthesiology, Pharmacology and Therapeutics,University of British Columbia, Vancouver, BC, Canada

M. J. Douglas, MD (&)Department of Anesthesia, BC Women’s Hospital, Rm 1Q72,4500 Oak Street, Vancouver, BC V6H 3N1, Canadae-mail: [email protected]

123

Can J Anesth/J Can Anesth (2011) 58:494–498

DOI 10.1007/s12630-011-9492-8

The declining use of GA in obstetrics has led to a

concern that there will be a rise in the number of difficult/failed intubations.5,8 Again, McKeen et al.’s study is

reassuring since the incidence of difficult/failed intubation

remained stable despite the decreased use of GA (from5.2% to 1%) over the 20-year study period.4 Palanisamy

et al. reported similar results in their study; i.e., a

remarkable decline in GA rate from 4.5% to 0.6%, (thanksto a concerted effort to avoid the obstetric airway) but no

increase in the rate of difficult/failed intubation.9 In con-

trast to these two studies where, if possible, a GA wasavoided, a review of 3,430 obstetric GAs from the UK over

eight years showed no failed intubations and a difficult

intubation rate of 1:149.10 The authors of the latter studysuggest their success was attributable, in part, to having a

high volume practice, readily ‘‘practicing’’ GA, when

appropriate, and the presence of skilled anesthesia assis-tants. To summarize,we have two studies on the one hand

that show a declining GA rate and, on the other, another

study that shows a large volume of GAs, and all threestudies show a difficult/failed intubation rate matching that

of the general surgical population. Hence, other than the

concern that the declining GA rate leads to trainees’ lack ofexperience in the obstetric airway, these three studies give

us hope that, in fact, our management of the obstetric

airway has improved.There are several possible reasons for this apparent

improvement in obstetric airway management, the mostlikely being early identification of the difficult airway.4

Early airway assessment allows for establishment of a

functioning epidural prior to the need for anesthesia for anoperative delivery or for planning an alternate technique

for intubation, such as awake intubation, should a GA be

required. Unfortunately, the study by McKeen et al. doesnot provide that information.4 In fact, airway documenta-

tion was completed on only 16.8% of the charts of patients

whose tracheas were intubated.With the changing demographic characteristics of the

obstetric patient, i.e., increasing maternal age and increas-

ing body weight – both identified as risk factors inMcKeen’s study4 – the issues of appropriate airway assess-

ment and subsequent anesthetic strategies become more

critical. Hood et al. were at the forefront in drawingattention to an increased risk of difficult tracheal intubation

in morbidly obese parturients.11 A large-scale Danish study

showed a weak but significant correlation of body massindex to difficult tracheal intubation in non-obstetric obese

subjects.12 Then again, Brodsky et al. found that obesity

alone did not predict difficult intubation, whereas, largeneck circumference and high Mallampati scores were

predictors.13 When placed in the ‘‘ramped’’ position, the

morbidly obese bariatric patient is easier to intubate; thistechnique should be used for all obese parturients.14

The study by McKeen et al. also points out the impor-

tance of vigilance in the postpartum period for womenrequiring GA.4 The only failed intubations occurred during

anesthesia for postpartum tubal ligation, and only one of

the two airways was predicted to be potentially difficult.Also, recent maternal mortality studies15,16 have pointed

out the importance of the postpartum period as airway

problems did not occur only at the time of induction (due tofailed intubation), but also at the time of extubation or in

the early postoperative period due to failure to reverse

neuromuscular blockade adequately and to monitorpatients appropriately.

How do we address the ‘‘other factors’’ that undoubtedly

contribute to the difficult obstetric airway? The crisismentality in the obstetric operating room when a GA is

required results in less than ideal conditions for intubation.

Consequences of time pressure include failure to place thepatient in the optimum position for tracheal intubation and

failure to assess the airway adequately. In addition, there is

less than adequate assistance for cricoid pressure in manyobstetric units, and the equipment may differ from that

used in the general operating room. If ever there were a

place for crisis resource management or use of simulation,it is in the setting of GA for the obstetric emergency.

Simulation should help the anesthesiologist (and trainees)

learn how to function efficiently during a crisis, and its useshould be mandatory for all individuals practicing obstetric

anesthesia.7

The caveat regarding the results of McKeen et al. is their

origin, i.e., a high-volume obstetrics unit where there is a

wealth of experience and where the labour epidural rate hasclimbed steadily.4 In the last reported five-year epoch, the

labour epidural rate was 80%, hence, GA could be avoided

more easily than in smaller centres without a 24-hr labouranalgesia service. Also, their anesthesia department has

established an excellent relationship with its obstetrical

care providers, ensuring antepartum assessment of womenwith medical conditions, obesity, and previous anesthetic

difficulties. Many anesthesia departments are challenged to

provide such a good antepartum consultation service, notonly from the resource perspective, but also from the

perspective of receiving appropriate referrals from obstet-

rical colleagues.So, can we claim, as the authors have claimed, that

‘‘intubation is not more difficult in the obstetric popula-

tion’’?4 Probably not. However, we can claim that theincidence of difficult/failed intubation in an obstetric

population will be similar to that of other surgical popu-

lations under the following conditions: 24-hr in-houseservice by obstetric anesthesiologists, the opportunity for

airway assessment either antepartum or early in labour,

and appropriate planning, including avoidance of GA in apatient with a predicted difficult airway. The use of

The obstetric airway 495

123


Zusammenfassung SectioMedikamente

Pabal (Carbetocin): Amp 1ml à 100µg• Dosis: 100µg als einmaliger Bolus über ca. 15 Sek. i.v. bei Sectio

(anschliessend kein routinemässiges Synto ad inf.)• Standort: Kühlschrank Vorbereitung W8

Syntocinon (Oxytocin) Amp 1 ml à 5 IE• Ind: Uterusatonie (Sectio), zervikales Priming• Dos: 5 IE in 100ml NaCl 0.9% als Kurzinfusion (100ml) i.v.

und 10-20 IE ad 1000 ml RL über 4-6 Std.• Standort: Kühlschrank Vorbereitung W8

Nitroglycerin• 100 – 200µg (bis 500µg fraktioniert) i.v. bei Sectio zur

Uterusrelaxation bei schwieriger (> 45 sek.) Kindsentwicklung

Phenylephrin• 50-100 μg -weise i.v.• first-line Medikament bei Hypotonie während Sectio, evt.

zusätzlich Ephedrin: 2.5-5 mg weise i.v. (Puls < 45)

MgSO4• Aufsättigung: 4 g in 100 ml NaCl 0,9% über 15-20 min., dann

Spiegelkontrolle• Erhaltungsdosis: 1-2 g /h (= 12.5-25 ml/h bzw. 4-8 Trpf./min)

Trandate• 10-20 mg-weise i.v., max. 300 mg i.v.• 400 mg 6 stdl. p.o., max. 2400 mg.• Standort: blauer Mediwagen Vorbereitung W8

Nepresol• 5 mg-weise i.v., max. 25 mg i.v.• Standort: blauer Mediwagen Vorbereitung W8

Remifentanil (Ultiva®) bei Sectio• 1 μg/kg als langsamer Bolus über 30s, dann 0.05 - 0.15 μg/kg/min

(bei 20 µg/ml => 10 - 36 ml/h)

Tranexamsäure (Cyclocapron®)• 1-2 g i.v. bei postpartaler Blutung• Standort: blauer Mediwagen Vorbereitung W8

Lido 2% -CO2 mit Adrenalin 1:200’000• Mischung 1:200’000 = 1ml (=0.1mg) Adrenalin in 20 ml Lido 2% -

CO2.

Morphin 0.2mg/ml 10ml Ampullen• 0.5 ml = 100 µg spinal.• 10 ml = 2mg epidural

Aspirationsprophylaxe1. 30 ml Natrium-Citrat per os 2. 50 mg Zantic i.v.3. 10 mg Paspertin i.v.

Anästhesieverfahren zur SectioRegional-Niveau: immer mind. T4 für Sectio

Stufe I:

elektiv

Stufe II:

< 30 min.

Stufe III: < 10min

“roter Knopf”

liegende EDA

SPA

Allgem.-anästh.

- Aspirationstest!15-25 ml Lido 2% -CO2 + Adrenalin 1:200’000 bolusweise titrieren50 µg Fenta epid.

Aspirationstest!15-25 ml Chlorprocain 3% bolusweise titrieren50 µg Fenta epid.Nach ca. 10 min. Nachinjektion ca. 10ml Lido 2% -CO2 + Adrenalin 1:200’000

8-12.5 mg Bupi 0.5% hyperbar mit:10 µg Fenta100 µg Morphin(200 µg falls OIB)30-75µg Clonidin(bei Re-Sectio)

8-12.5 mg Bupi 0.5% hyperbar mit:10 µg Fenta100 µg Morphin(200 µg falls OIB)30-75µg Clonidin(bei Re-Sectio)

wie linksbei Zeitdruck Zusätze weglassen

- - siehe Schema

Postoperative AnalgesieMorphin Tropfen und Brufen per os gemäss Standardverordnungen

KEIN Novalgin

AWR: Morphin 2mg weise i.v.

SpinalanästhesieMorphin 100 - 200 µg (gute Analgesie bis 24h postop)

Epiduralanästhesie:Morphin 2mg epidural (gute Analgesie bis 24h postop)

Epiduralkatheter nach Sectio entfernen ! (Ausnahme Gerinnungsstörung, zB Tc-Penie bei HELLP oder bei medianer Laparotomie)

Stufe III in Allgemeinanästhesiebei z.B persistierender kindlicher Bradykardie <60, Uterusruptur, massiver Hypovolämie. RSI-ITN im Sectiosaal W8:

Präoxygeniereung

Thiopental 4-7 mg/kgSuccinylcholin ca. 0.7 mg/kg

Krikoiddruck, Apnoe

IntubationTubuskontrolle (CO2 !)

Schnitt

Sevo od. Isofl. max 1 MACN2O 60%

Abnabelung

Fentanyl 2-3 µg/kgMidazolam 3-5 mg

evtl. Esmeron 0.3mg/kg

ExtubationWach, Schutzreflexekeine Restrelaxation

Präeklampsie, Kardiovask. Krkh:Remifentanil 1 μg./kg langsamer

Bolus, dann 10-36 ml/h

• 86546 resp. 86300 orientieren (so früh wie möglich)

Telefonnummern

Ana-AA 86600 OA Ana Gebs 181-9011

Ana-Pfl (Sectio) 86450 GIT 86460

Ana-OA West 86546 Gebs 59049/50

Ana-OA Ost 86300 AA-Gebs 87600

OIB 87300/87200 OA-Gyn/Gebs 87880

Wochenbett 59093 / 86 AA-Gyn 87700

Gyn 4.OG 59231 Labor Hämat. 54260

Rohrpost Gebs 2540 Blut bestellen 52091

Th. Girard, Oktober 2011


Preoxygenation

Thiopental 4-7 mg/kgSuccinylcholine ca. 0.7 mg/kg

Cricoid pressure, Apnea

Intubationcheck position (CO2 !)

Incision

Sevo or. Isofl. max 1 MAC(N2O 60%)

cord clamping


evtl. Esmerone 0.3mg/kg

Extubationawake, reflexes !no curarisation !

Preeclampsia, cardiovasc disease:

Remifentanil 1 μg./kg slow bolus, then 10-36 ml/h


Preoxygenation




Incision


cord clamping






allergy ?prev. anesthesia ?

weight ?


British Journal of Anaesthesia 95 (5): 706–9 (2005)

doi:10.1093/bja/aei231 Advance Access publication September 2, 2005

Pre-oxygenation in the obese patient: effects of position ontolerance to apnoea

F. R. Altermatt*, H. R. Munoz, A. E. Delfino and L. I. Cortınez

Departamento de Anestesiologıa, Escuela de Medicina, Pontificia Universidad Catolica de Chile, Chile

*Corresponding author. E-mail: [email protected]

Background. In obese patients, reduced functional residual capacity exacerbated by supineposition might decrease the effectiveness of pre-oxygenation and the tolerance to apnoea.The aim of this study was to compare the effect of body posture during pre-oxygenation, sittingor supine, on its effectiveness in obese patients.

Methods. Forty obese patients (BMI >35 kg m!2) undergoing surgery with general anaesthesiawere randomly assigned to one of two groups: Group 1 (sitting, n=20) or Group 2 (supine, n=20).In the predetermined body position, pre-oxygenation was achieved with eight deep breaths within60 s and an oxygen flow of 10 litre min!1. After rapid sequence induction of anaesthesia indecubitus position, the trachea was intubated and the patient was left apneic and disconnectedfrom the anaesthesia circuit until SpO2

decreased to 90%. The time taken for desaturation to90% from the end of induction of anaesthesia was recorded. Arterial blood oxygen tension wasmeasured before (baseline) and after pre-oxygenation. Values were compared with two-wayANOVA and unpaired Student’s t-test.

Results.Oxygen and carbon dioxide tensions were similar between groups, both at baseline andafter pre-oxygenation. However, the mean time to desaturation to 90% was significantly longerin the sitting group compared with the supine group [mean (SD): 214 (28) vs 162 (38) s, P<0.05].

Conclusions. Pre-oxygenation in sitting position significantly extends the tolerance to apnoea inobese patients when compared with the supine position.

Br J Anaesth 2005; 95: 706–9

Keywords: anaesthetic techniques, pre-oxygenation; complications, obesity; position, effects

Accepted for publication: August 1, 2005

Management of obese patients (BMI > 30 kgm!2) representsa challenge for the anaesthetist in many ways, particularlyadequate airway management during induction. A BMIgreater than 26 kg m!2 is a strong predictor of higher riskof difficult ventilation with facemask1 and, arguably,associated with a greater risk of difficult intubation andaccompanying desaturation.2 This setting emphasizes theimportance of an adequate pre-oxygenation to maximizethe period of non-hypoxaemic apnoea that obese patientscan tolerate.

In patients of normal weight, the effectiveness of pre-oxygenation varies with the technique. A forced vitalcapacity ventilation for eight breaths during 60 s withhigh flows of oxygen 100% was shown to achieve adequatedenitrogenation and slower desaturation during apnoeacompared with the usual 3 min tidal-volume ventilationtechnique.3

Obesity, however, affects pulmonary function that canseriously impair the effectiveness of pre-oxygenation; themain reason being a decrease in functional residual capacity

(FRC) secondary to cephalad diaphragmatic displacement.4

Thus, in obese patients desaturation of arterial blood afteronset of apnoea is reached within a significantly shorter timethan in a non-obese patient.5

Since FRC is highly sensitive to changes in bodyposition, being larger in the upright or sitting than in thesupine position,6 we hypothesized that the efficacy of pre-oxygenation in obese patients might be improved by modi-fying the position of the patient during this manoeuvre.Thus, the aim of this study was to compare the effect of

the sitting against the supine position, in obese patients, onthe effectiveness of pre-oxygenation defined as the durationof non-hypoxaemic apnoea.

MethodsAfter institutional Ethics Committee approval, and obtainingwritten informed consent, 40 unpremedicated obesepatients (BMI >35 kg m!2), ASA II or III, undergoingelective surgery with general anaesthesia, were studied.

! The Board of Management and Trustees of the British Journal of Anaesthesia 2005. All rights reserved. For Permissions, please e-mail: [email protected]

at University of Basel / U

niversity Library on February 12, 2011bja.oxfordjournals.org

Dow

nloaded from

SaO2 90%214 vs. 162s


Preoxygenation




Incision


cord clamping







ORIGINAL ARTICLE

Difficult and failed intubation in obstetric anaesthesia: anobservational study of airway management and complicationsassociated with general anaesthesia for caesarean section

N. J. McDonnell, M. J. Paech, O. M. Clavisi, K. L. Scott, the ANZCA Trials GroupThe School of Medicine and Pharmacology, The University of Western Australia and the Department of Anaesthesiaand Pain Medicine, King Edward Memorial Hospital for Women, Perth, Western Australia, Australia

ABSTRACTBackground: Recent developments in anaesthesia and patient demographics have potentially changed the practice of obstetric gen-eral anaesthesia. There are few contemporary data on Australasian practice of general anaesthesia for caesarean section, especiallyrelating to airway management, anaesthetic techniques and complications.Methods: Using a standardised case record form, a prospective observational study was conducted during 2005-06 in 13 maternityhospitals dealing with approximately 49 500 deliveries per annum. Patient demographics, airway management, anaesthetic tech-niques and major complications were evaluated in those given general anaesthesia.Results: Data were obtained from 1095 women receiving general anaesthesia for caesarean section, 47% of which were classified ascategory 1 and 18% as category 4. Tracheal intubation was planned in all cases with rapid-sequence induction used in 97%. Agrade 3 or 4 laryngoscopic view was obtained in 3.6 and 0.6% of cases respectively, with 3.3% considered a difficult intubation.There were four failed intubations (0.4%, 95% CI 0.01-0.9%), of which three were subsequently managed using a laryngeal maskairway. Antacid prophylaxis was used in 94% of elective cases and 64% of emergencies. Regurgitation of gastric contents was notedin eight cases (0.7%, 95% CI 0.2-1.2%), with one confirmed case of aspiration (0.1%, 95% CI 0.002-0.5%). There were no cases ofserious airway-related morbidity.Conclusions: General anaesthesia is most commonly used in emergency situations. Tracheal intubation after rapid-sequence induc-tion remains the predominant approach to airway management in Australasia. The incidence of failed intubation is consistent withprevious studies. Aspiration prophylaxis is not routinely used for emergency surgery.

!c 2008 Elsevier Ltd. All rights reserved.

Keywords: Anaesthesia, general; Anaesthesia, obstetric; Airway management; Intubation, fsailed

Introduction

As a result of a number of factors, including the likelyinfluence of recommendations made over 20 years agoin the UK Confidential Enquiries into Maternal Deaths,there has been a widespread shift away from generalanaesthesia and toward regional anaesthesia for caesar-ean section. In many countries general anaesthesia isnow used only for a small minority of caesarean sec-tions, predominantly those where surgery is not elec-

tive.1–3 General anaesthesia for caesarean sectionappears to be associated with higher rates of seriousand life-threatening complications than regional anaes-thesia3,4 and most anaesthetic-related maternal deathsstill result from complications of airway managementduring general anaesthesia.5–7

Nevertheless a number of indications for generalanaesthesia remain, but the declining use of generalanaesthesia in the obstetric population has raised con-cern that safety standards may be compromised as a re-sult of inadequate exposure to this technique andinsufficient training in airway management for the preg-nant woman.8 Furthermore, the demographic of theobstetric population is changing in many countries, withthe average age and weight of women giving birth risingand the medical complexity of cases increasing.9

The major concerns in providing general anaesthesiafor caesarean section are potential difficulty with airwaymanagement, the risk of awareness and the possible

Accepted January 2008

This study was supported by a starting grant from the Australian andNew Zealand College (ANZCA) Trials Group, followed by a 2006project grant from ANZCA.Correspondence to: Nolan J. McDonnell, Specialist Anaesthetist,Department of Anaesthesia and Pain Medicine, King Edward Memo-rial Hospital for Women, 374 Bagot Rd., Subiaco, Western Australia6008 Australia. Tel.: +61 411 298 631; fax: +61 8 93402260.E-mail address: [email protected]

International Journal of Obstetric Anesthesia (2009) 17, 292–2970959-289X/$ - see front matter !c 2008 Elsevier Ltd. All rights reserved.doi:10.1016/j.ijoa.2008.01.017



Results

A total of 1095 cases were entered into the study duringthe 18-month study period. The majority of cases (85%)were from seven large tertiary centres each performingbetween 4000 and 7000 deliveries per year. The remain-ing 15% were spread across six smaller regional centres(Table 1). The mean age was 30 years (range 18-51)and the median weight 76 kg (range 34-170 kg). Ninetypercent of patients were ASA status 1 or 2, 96 patients(9%) were ASA 3, 10 (1%) were ASA 4 and 1 patient(0.1%) was ASA 5.

Of the 1095 caesarean sections, 47% were classified ascategory 1, 18% as category 4 and the remaining 35% ascategory 2 or 3. The most common indications (multipleoptions possible at the anaesthetist’s discretion) for gen-eral anaesthesia were need for immediate delivery of thefetus, obstetrician request, failed regional block and pa-tient request (Table 2).

Tracheal intubation was the planned airway manage-ment method for all patients. A rapid-sequence induc-tion using cricoid pressure and suxamethonium wasused in 97% of cases, with 22 of 1092 (2%) having amodified rapid-sequence induction using rocuronium,2 (0.2%) a gaseous induction and 1 (0.1%) an electiveawake fibreoptic intubation. Laryngoscopic views areshown in Table 3. Intubation was performed by a con-sultant anaesthetist in 23% of 1066 cases, an advancedtrainee (more than two years of formal Australasiantraining) in 49% and a basic trainee (within their firsttwo years of Australasian training) in 23%. The median(IQR) times from induction to intubation, induction todelivery, uterine incision to delivery, induction to com-pletion of surgery end and induction to extubation were45 s (30-60), 5 min (3-10), 60 s (30-90), 40 min (34-50)and 49 min (40-60) respectively.

In 61 women (6%) intubation was predicted as likelyto be difficult and in three (0.3%) it was known thatintubation was difficult. One hundred and seventy-eightpatients (17%) were assessed as obese by the proceduralanaesthetist (definition at their discretion). Intubationwas classified as difficult in 36 of 1095 patients (1 in30) (3.3%, CI 2.3-4.5%) and failed intubation occurredin four patients (1 in 274) (0.4%, CI 0.01-0.9%). Of the

36 difficult intubations, the laryngoscopic view wasgrade 3 in 39% and grade 4 in 14% (Table 3). The like-lihood of encountering a difficult intubation was not re-lated to age (P = 0.09), weight (P = 0.59), urgency(P = 0.85) or ASA status (P = 0.31) but was predictedby the experience of the anaesthetist, with a specialistanaesthetist being more likely to be involved with a dif-ficult intubation (OR 2.6, CI 1.3-5.3, P = 0.009). Two ofthe cases of failed intubation had a grade 3 and two agrade 4 view. Two of the failed intubations had beenclassed as a ‘‘predicted difficult intubation’’.

Women whose tracheas proved difficult to intubatehad a weight range of 50 to 140 kg (median 80 kg) whilethose in whom intubation failed ranged from 50 to 73 kg(median 57 kg). Overall, 14% of women included in thestudy weighed 100 kg or more compared with 25% ofthose who were difficult to intubate. Using logisticregression analysis a weight of 100 kg or more was notan independent predictor of a difficult intubation (OR1.74, CI 0.796-3.78, P = 0.166).

The laryngeal mask airway was used in all four failedintubations. One failed intubation occurred at an elec-tive caesarean section; in this case the intubating laryn-geal mask (ILMATM) enabled effective ventilation,although the anaesthetist was unable to intubatethrough the ILMA device and the patient was wokenup. A regional anaesthetic was subsequently performed.The other three failed intubations all arose in category 1caesarean sections. In each case the surgery was allowedto proceed by an advanced trainee after successful inser-tion and airway control with a ProSealTM laryngealmask (n = 2) or a ClassicTM laryngeal mask (n = 1).

Regurgitation of gastric contents was seen in eight of1095 patients (0.7%, CI 0.2-1.2%), with four episodes atinduction of anaesthesia and five at extubation (one atboth intubation and extubation). Two cases of regurgi-tation were at elective caesarean section. There werefour possible cases and one (0.1%, CI 0.002-0.5%) con-firmed case of pulmonary aspiration. Severe hypoxa-emia occurred in 24 patients (2%, CI 1.4-3.2%),bronchospasm in 13 (1%, CI 0.6-2.0%) and laryngo-spasm in three (0.3%, CI 0.06-0.8%).

The use of medications for prophylaxis against aspi-ration varied depending on the urgency of the caesareansection (Fig. 1). Of category 1 cases, 64% received someform of pharmacological prophylaxis, while 94% of

Table 2 Indication for general anaesthesia

n = 1095 n (%)

Immediate delivery mandated 471 (43)Obstetrician request 321 (29)Failed regional block 272 (25)Maternal request 260 (24)Actual or potential haemodynamic disturbance 231 (21)Coagulopathy/bleeding risk 58 (5.3)Sepsis 44 (4.0)Other 169 (15)

Table 3 Cormack and Lehane laryngoscopic viewobtained (n = 1086)

View All Di!cultintubation n = 36

Failedintubation n = 4

Grade 1 882 (81%) 6 (17%) 0 (0%)Grade 2 159 (15%) 11 (31%) 0 (0%)Grade 3 39 (3.6%) 14 (39%) 2 (50%)Grade 4 6 (0.6%) 5 (14%) 2 (50%)

Values are n (%).

294 Obstetric general anaesthesia airway complications


Copyright © European Society of Anaesthesiology. Unauthorized reproduction of this article is prohibited.

CE: Namrta; EJA/200652; Total nos of Pages: 2;

EJA 200652

CorrespondenceEuropean Journal of Anaesthesiology 2011, 28:000–000

General anaesthesia for caesarean sections:are anaesthetists dealing with exaggeratedfear?Muhammad Ajmal

From the Department of Anaesthesia, Letterkenny General Hospital, Letterkenny,Ireland

Correspondence to Muhammad Ajmal, Department of Anaesthesia, CorkUniversity Hospital, Cork, IrelandTel: +353 860231261; fax: +353 214546434; e-mail: [email protected]

IntroductionGeneral anaesthesia for caesarean sections (c-sections)is feared to be associated with high incidence ofairway problems and so the majority of c-sections areperformed under regional anaesthesia which decreasesthe experience of anaesthetists in general anaesthesiafor such procedures.1–4 Therefore, young anaesthetistsinvariably face a lot of pressure when administeringgeneral anaesthesia to obstetric patients, especially inemergency conditions.2 Based on an 8-year experienceof general anaesthesia for c-sections at Aziz FatimaHospital, Faisalabad, Pakistan, our point of view ongeneral anaesthesia for c-sections is slightly differentfrom the current popular point of view on this subject.We believe that in the absence of additional risk, forexample obesity, pregnancy alone does not significantlyincrease the risk of airway complications in obstetricpatients. We report here our experience/observationsabout the incidence of regurgitation and failed intubationinvolving patients primarily scheduled for c-sectionsunder general anaesthesia.

MethodsAfter the approval of an ethical committee of the AzizFatima Hospital, Faisalabad, Pakistan, of the protocol‘GA for c-sections 1991–1999’ (Chairperson Dr TariqJavid), a retrospective observational study was performedto determine the incidence of regurgitation and failedintubation during an 8-year period from 1991 to 1999in parturients who received general anaesthesia for theirc-sections. The patients who had general anaesthesiafollowing a failed spinal block were excluded. Data wereretrieved from a paper-based anaesthesia and postopera-tive record.

During the 8 years, there was a consistent techniquefor induction of general anaesthesia for c-sections.Anaesthesia was managed by a team of four experiencedanaesthetists consisting of a consultant and three staffgrade professionals. Patients were given no antacid pre-medication. Anaesthesia was induced after draping the

patient, and a surgeon was standing by ready to proceedimmediately after tracheal intubation was achieved.The patient’s head was stabilised on a sand bag insniffing position and the body was placed in a slightreverse-Trendelenburg position. Each patient was givenmetclopramide 10 mg intravenously followed by preoxy-genation for 3 min, a sleeping dose of thiopentone (4–6 mg kg!1 body weight) and suxamethonium (1.5 mg kg!1

body weight) to intubate the trachea. No cricoid pressurewas applied and lungs were gently mask ventilated untilfull relaxation was achieved. No other device excepta laryngoscope and a gum-elastic stylet was availablefor airway management. Occurrence of clinical and sub-clinical regurgitation was based on anaesthetist’s directobservation and on perioperative clinical and radiologicalindicators in suspected patients. Patients who developedpostoperative problems such as a cough, fever, and so onwere investigated. Endotracheal intubation was assumedto have failed if general anaesthesia was maintained fora c-section without an intubation or general anaesthesiawas terminated to consider an alternate form of anaes-thesia for the c-section.

ResultsA total of 2114 parturients received general anaesthesiaof which 1018 were assessed as American Society ofAnesthesiologists-I (ASA-I), 1004 ASA-IE, 66 ASA-IIand 26 as ASA-IIE. Of the 2114 c-sections, 1030 (49%)were emergency procedures. Thirty (1.4%) patients wereassessed having Mallampati-III grade. No study patienthad any other major risk factor for regurgitation, for exam-ple morbid obesity, gastro-esophageal reflux or opioidlabour analgesia. Other parturient-related characteristicsare summarised in Table 1.

No incidence of clinical/subclinical regurgitation or afailed intubation in the study population was observed(0/2114). Eight (0.4%) patients complained of mildhoarseness immediately after recovery from anaesthesiaand this was determined to be due to inadvertentlaryngeal trauma during endotracheal intubation. Five(0.23%) patients presented with fever and rigors on the2nd postoperative day. Three (0.14%) of those patientswere diagnosed as having a urinary tract infection and two(0.09%) having bilateral basal atelectasis of lungs. Chestradiographs of those patients did not show any featuresuggestive of pulmonary aspiration.

DiscussionResults of this study indicated that the incidence ofairway complications related to general anaesthesia forc-sections in the study population was extremely low

0265-0215 ! 2011 Copyright European Society of Anaesthesiology DOI:10.1097/EJA.0b013e3283499f3f


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Journal of Clinical Pharmacy and Therapeutics (1998) 23, 19–23

Placental transfer and neonatal effects of propofol incaesarean sectionA. Sanchez-Alcaraz, M. B. Quintana and M. Laguarda*Department of Pharmacy, Arnau de Vilanova Hospital, Valencia and *Department of Anaesthesiology,Maternal La Fe Hospital, Valencia, Spain

SUMMARY drug transference can be divided into two groups: (i)factors related to the drug, where the physico-chemical

Objective: To assess transplacental passage of pro-properties of the anaesthetic used are directly involved,

pofol by measuring the levels in maternal and foetaland (ii) the anatomical characteristics of the maternal,

plasma, and the possible relationship between theplacental and foetal circulation. It is extremely im-

latter and the neonatal effects when propofol is usedportant to know these processes in order to predict

as an induction agent in obstetric anaesthesia forboth the local and the systemic pharmacological effects

performing a caesarean section to terminate preg-and to prevent the eventual risk of toxicity from the

nancy.drugs used during anaesthesia (1).

Methods: Intravenous propofol was administered asAlthough the use of propofol has been widely as-

an anaesthesia-inducting agent at doses of 2 mg/sessed in surgical patients, studies conducted in ob-

kg in 10 healthy women (ASA I-II). The propofolstetric patients are less common. Propofol has been

concentrations were measured by high-performanceused as an induction agent in obstetric anaesthesia at

liquid chromatography (HPLC).doses of 2·0–2·8 mg/kg, administered rapidly (ª10 s)

Results: After induction, hypnosis was achieved inby intravenous injection (2). In comparative studies

all patients within 75 s, and it took 4–10 min to deliverwith thiopental, the doses needed to abolish the pal-

the foetus. Apgar test scores were high in seven ofpebral reflex are 2·15±0·26 mg/kg of propofol, as

the 10 neonates, in three cases the score was 5 or less.opposed to 4·53±0·65 mg/kg of thiopental (3). Also the

The mean values in venous maternal blood weretime required is 27·3±4·3 s after induction with propofol

5·01±1·06 lg/ml 1 min after propofol administrationat doses of 2·5 mg/kg, and 32·4±10·4 s after administra-

and 1·47±0·35 lg/ml at the time of delivery.tion of 5 mg/kg of thiopental (4). In some cases its use

Propofol crossed the placental barrier with levelsis associated with neonatal depression (2).

in the umbilical cord of 0·32±0·10 lg/ml in the veinThe data published on transplacental pharmaco-

and 0·22±0·08 lg/ml in the artery.kinetics of propofol refer to levels in maternal and

Conclusion: Propofol plasma levels in the newborn atfoetal plasma at the time of delivery (5–8).

the time of delivery depend on the level in maternalThe purpose of this study was to assess trans-

plasma, and therefore on the dose used for inductionplacental passage by measuring the propofol levels in

and the time lapsed between the administration ofmaternal and foetal plasma, and the possible re-

the drug and the delivery of the foetus.lationship between the latter and the neonatal effectswhen propofol is used as an induction agent in ob-

INTRODUCTION stetric anaesthesia for performing a caesarean sectionto terminate pregnancy.

The caesarean section is mainly conditioned both by thepresence of the foetus and by the transplacental passageof all the drugs used in the anaesthesia and their possible

MATERIALS AND METHODSeffects on the foetus. The main determinants of placental

PatientsCorrespondence: Dr A. Sanchez-Alcaraz, Servicio de Farmacia,

The population included in this study (Table 1) com-Hospital Arnau de Vilanova, San Clemente, 26, 46015 Valencia,Espana. prised 10 healthy women with no type of disease, in

” 1998 Blackwell Science Ltd 19

22 A. Sanchez-Alcaraz et al.

volume in the central compartment (Vc) was 0·44±0·12litres/kg. This value of distribution volume in the Vcwas higher than that found in surgical patients (Vc=0·28±0·02 litres/kg) (12).

The mean value of the UA/UV ratio was0·68±0·13 lg/ml, suggesting a propofol uptake by thefoetal tissues, whereas propofol metabolism in theplacenta must be slight owing to the fact that theenzymatic activity of glucuronic conjugation in theplacental tissues was insignificant. Therefore theplacental barrier is negligible for propofol, which israpidly transferred to the foetal circulation.

The values of the UV/MV ratio ranged from 0·15to 0·30. There is a linear relationship between thepropofol levels in the umbilical vein and artery and

Fig. 1. Relationships between propofol plasma levels in the maternal plasma level at the time of foetal delivery,the umbilical vein and maternal vein (UV=-0·02+0·23. with correlation coefficients of 0·83 and 0·78, re-MV, correlation coefficient=0·83, P<0·01) and between

spectively (Fig. 1).umbilical artery and maternal vein (UA=-0·05+0·18.In all the cases, the removal of the foetus occurredMV, correlation coefficient=0·78, P<0·01).

during the propofol distribution phase (4–10 min).Therefore, placental transference ceases, a steady stateis not achieved and cord levels are lower than the

Table 4 shows the pharmacokinetic parameters, es- theoretical maximum plasma level. Thus, differenttimated from the maternal levels, of the relationship plasma levels can be expected in the umbilical cord,between levels in maternal plasma and the umbilical and also different UV/MV values depending on thevein (UV/MV) and of the relationship between levels time taken to deliver the foetus.in the umbilical artery and vein (UA/UV). The half-life was 4·7±0·94 min, and the initial distribution

CONCLUSION

Table 4. Pharmacokinetic parameters of propofol fol- Propofol plasma levels in the newborn at the time oflowing i.v. injection of 2 mg/kg delivery depend on the level in maternal plasma, and

therefore on the dose used for induction and the timelapsed between administration of the drug and thet1

2 VcCase (min) (litres/kg) UV/MV UA/UV extraction of the foetus. The rapid placental trans-

ference of propofol during caesarean section can some-times make it necessary to give additional doses, either

1 4·53 0·43 0·27 0·61by rapid i.v. injection or by maintaining the anaesthesia2 3·34 0·58 0·23 0·42by continuous i.v. infusion. In these circumstances the3 6·47 0·72 0·15 0·49administration must be made with caution to prevent4 4·78 0·32 0·30 0·78foetal effects, particularly in those cases in which the5 4·09 0·37 0·22 0·73period of time between the onset of induction and the6 3·95 0·35 0·19 0·81

7 4·89 0·42 0·19 0·75 removal of the foetus is prolonged.8 4·46 0·32 0·22 0·679 6·34 0·44 0·22 0·68

10 4·37 0·42 0·17 0·86 REFERENCESMean 4·72 0·44 0·22 0·68

1. Kanto J. (1986) Obstetric analgesia. Clinical pharmaco-±SD 0·94 0·12 0·04 0·13CV (%) 19·9 27·8 19·9 19·5 kinetics considerations. Clinical Pharmacokinetics, 11, 283–

298.

” 1998 Blackwell Science Ltd, Journal of Clinical Pharmacy and Therapeutics, 23, 19–23


Gin T et al. Maternal and fetal levels of propofol at caesarean section.

Anaesth Intensive Care. 1990;18:180.

UV/MV ratio: 0.65 (0.56-0.74)

Apgar scores were higher with shorter incision to

delivery times


Preoxygenation




Incision


cord clamping







Anesthesiology 2003;99:1050-4


Discussion

The duration of action (at the adductor pollicis) ofsuccinylcholine-induced block that we report is virtuallyidentical to the observations of Viby-Mogensen12 and isquite similar to the observations of other investiga-tors13–15 (Table 3).

In a recent letter in the Journal, we suggested that theusually cited 1.0-mg/kg “intubation dose” of succinylcho-line was unnecessarily large.16 It was hypothesized thata smaller dose (0.50–0.60 mg/kg) might enhance overallpatient safety if this reduced dose resulted in a signifi-cant reduction in the duration of succinylcholine-in-

duced apnea. Previously published data (Table 3) sug-gested that reducing the dose of succinylcholine from1.0 to 0.5 mg/kg should decrease the duration of neuro-muscular block by more than 4 min.17–19 Although allrecovery intervals (T10 through T90) that we measuredwere shorter after 0.60 mg/kg succinylcholine comparedto the 1.0 mg/kg dose, the magnitude of these differ-ences was less than we anticipated. A 40% decrease indose does not result in a comparable reduction in thedrug’s duration of effect.

Only limited information is available on how thetwitch response at the adductor pollicis following suc-

Fig. 1. Twitch height (T1) as a percent of control at the adductor pollicis versus timefrom initial drug bolus for three different doses of succinylcholine.

Table 3. Offset Characteristics of Succinylcholine 0.50, and 1.0 mg/kg (Historic Controls)

Dose (mg/kg) n

Duration

ReferenceT10 T25 T50 T75 T90

0.5 13 4.6 ! 1.4 5.9 ! 1.6 7.4 ! 2.1 171.0 15 8.1 ! 3.0 10.1 ! 3.0 12.1 ! 3.40.5 12 4.8 ! 1.3 6.3 ! 1.6 8.3 ! 2.5 18

(3.3 –7.5) (4.3 –10) (5.2 –13.5)1.0 12 8.5 ! 2.2 10.6 ! 2.5 13.2 ! 3.2

(5.8 –11.7) (7.1 –13.9) (8.1 –17.7)0.5 20 5.5 6.7 7.9 10.1 19

(1.5 –9.4) (2.0 –10.6) (2.7 –12.2) (1.2 –16)1.0 20 10.2 11.3 12.4 14.6

(4.1 –15.4) (5.1 –16.9) (6.2 –18.1) (8.3 –21)1.0 41 5.6 ! 2.1 7.0 ! 2.7 8.7 ! 3.1 9.3 ! 3.3 12

(4.0 –8.0) (4.5 –10.0) (6.0 –12.0) (6.0 –13.0)1.0 31 9 ! 3 11.5 ! 3 131.0 15 8 ! 2.5 10.6 ! 3.3 141.0 15 7.6 10.5 15

(5.7 –11.3) (7.8 –13.8)

Durations T10, T25, T50, etc., are the times (min) from succinylcholine bolus administration to 10%, 25%, 50%, etc., recovery of twitch height compared to initialcontrol values. Data are expressed as mean ! SD (range). T10 duration for reference 12 is time to first detectable twitch.

1052 KOPMAN ET AL.

Anesthesiology, V 99, No 5, Nov 2003

Anesthesiology 2003;99:1050-4


H.E. Marcus · A. Behrend · R. Schier · O. Dagtekin · P. Teschendorf · B.W. Böttiger · F. SpöhrKlinik für Anästhesiologie und Operative Intensivmedizin, Universitätsklinik Köln

Anästhesiologisches Management der Sectio caesareaDeutschlandweite Umfrage

Originalien

Nach Angaben des Statistischen Bun-desamts bringen anteilig immer mehr Schwangere in Deutschland ihr Ba-by per Kaiserschnitt zur Welt. Die an-ästhesiologische Versorgung der Sec-tio caesarea (SC) gewinnt somit zu-nehmend an Bedeutung. Im Rahmen des anästhesiologischen Manage-ments der SC gibt es einige sehr in-tensiv diskutierte Fragen, die sich z. T. aufgrund mangelnder Evidenz nicht eindeutig beantworten lassen. Eine Orientierung für den geburtshilflich tätigen Anästhesisten kann hier die im eigenen Land gängige Praxis ge-ben, die sich durch eine systemati-sche Befragung der geburtshilflich aktiven anästhesiologischen Kliniken erfassen lässt.

Fragestellung

Die Spinalanästhesie (SPA) hat sich in Deutschland im Vergleich zu anderen Ländern spät etabliert und war !""! in #",#$ der Kliniken Verfahren der Wahl. Zuverlässige Daten zur Bedeutung der SPA zur SC aus jüngster Zeit sind in Deutschland nicht verfügbar. Eine weite-re stark diskutierte Frage des anästhesio-logischen Managements der SC betrifft die prophylaktische Flüssigkeitstherapie vor Beginn einer SPA. Eine Umfrage in den USA aus !""% ergab, dass das Hydrie-ren der Patientinnen vor einer SPA zur SC und die sympathomimetische Therapie

mit Ephe drin zur gängigen Praxis gehören [&]. Dagegen ist unklar, welche Maßnah-men in Deutschland zur Prophylaxe und Therapie von Hypotonien ergriffen wer-den. Die Deutsche Gesellschaft für Anäs-thesiologie und Intensivmedizin (DGAI) empfiehlt hier eine Kohydratation mit Kolloiden ['"]. Die Inzidenz postspinaler Kopfschmerzen ist u. a. von den verschie-denen Größen und Typen der verwende-ten Spinalnadeln abhängig. Obwohl die-se Tatsache vielen geburtshilflich tätigen Anästhesisten bekannt sein dürfte, ist un-klar, inwieweit die Verwendung atrauma-tischer, kleinlumiger Kanülen in die Pra-xis umgesetzt ist. Auch im Hinblick auf Zahl und Art venöser Zugänge sind der-zeit in der Literatur keine genauen Emp-fehlungen zu finden. Ein weiterer Aspekt ist die perioperative Gabe von Antibiotika bei der SC. Patientinnen mit SC profitie-ren von einer präpartalen antibiotischen Therapie, weil durch diese die Inzidenzen einer Endometritis und von Wundinfek-tionen gesenkt werden können [(, !']. In diesem Zusammenhang stellt sich die Fra-ge, ob und wann eine antibiotische The-rapie deutschlandweit zur SC eingeleitet wird.

Klinikinterne „standard operating procedures“ (SOP) oder Leitlinien kön-nen helfen, Entscheidungen von An-ästhesisten zur angemessenen Versor-gung bei spezifischen klinischen Um-ständen zu unterstützen. Idealerweise sind sie wissenschaftlich fundierte, pra-

xisorientierte Handlungsempfehlungen, die Orientierung im Sinne von Entschei-dungs- und Handlungsoptionen bieten. Auch hier stellt sich die Frage, wie vie-le Kliniken SOP oder Leitlinien zum an-ästhesiologischen Vorgehen bei der SC, der medikamentösen Therapie postpar-taler Hämorrhagien und der postope-rativen Schmerztherapie nach einer SC entwickelt haben. Die aktuell erhobenen Daten zum anästhesiologischen Manage-ment der SC aus dem Jahr !""( sollen dem Leser ) Jahre nach der letzten Er-hebung einen Überblick über die anäs-thesiologische Versorgung in Deutsch-land geben. Darüber hinaus werden in dem Fragebogen auch in der Literatur kontrovers oder bislang wenig diskutier-te Themen und deren Handhabung in Deutschland abgebildet, die in Relation zu internationalen aktuellen Erkenntnis-sen gesetzt werden.

Studiendesign und Untersuchungsmethoden

Ein Fragebogen zum anästhesiologischen Management der SC wurde entwickelt und nach einer Pilottestung im August !""( deutschlandweit an %"* Chefärzte von Anästhesieabteilungen mit geburts-hilflichem Aufgabenspektrum (Quel-le: Deutsches Krankenhaus Adressbuch !""() versandt. Es folgte kein Erinne-rungsschreiben. Der anonymisierte Fra-gebogen umfasste #! Multiple-Choice-

RedaktionR. Rossaint, Aachen

Anaesthesist 2011 DOI 10.1007/s00101-011-1931-yEingegangen: 4. April 2011Überarbeitet: 27. Juni 2011Angenommen: 7. Juli 2011© Springer-Verlag 2011

1Der Anaesthesist 2011 |

1.7 % general anesthesia

55.8 % precurarisation


Preoxygenation




Incision


cord clamping







Anesthesiology 2009; 110:1020–5 Copyright © 2009, the American Society of Anesthesiologists, Inc. Lippincott Williams & Wilkins, Inc.

Reversal of Profound Neuromuscular Block bySugammadex Administered Three Minutes afterRocuronium

A Comparison with Spontaneous Recovery from SuccinylcholineChingmuh Lee, M.D.,* Jonathan S. Jahr, M.D.,† Keith A. Candiotti, M.D.,‡ Brian Warriner, M.D.,§Mark H. Zornow, M.D.,! Mohamed Naguib, M.D.#

Background: Rocuronium in intubation doses providessimilar intubation conditions as succinylcholine, but has alonger duration of action. This study compared time to sug-ammadex reversal of profound rocuronium-induced neuro-muscular block with time to spontaneous recovery fromsuccinylcholine.

Methods: One hundred and fifteen adult American Society ofAnesthesiologists Class I-II surgical patients were randomizedto this multicenter, safety-assessor–blinded, parallel group, ac-tive-controlled, Phase IIIa trial. Anesthesia was induced andmaintained with propofol and an opioid. Neuromuscular trans-mission was blocked and tracheal intubation facilitated with 1.2mg/kg rocuronium or 1 mg/kg succinylcholine. Sugammadex(16 mg/kg) was administered 3 min after rocuronium adminis-tration. Neuromuscular function was monitored by accelero-myography. The primary efficacy endpoint was the time fromthe start of relaxant administration to recovery of the firsttrain-of-four twitch (T1) to 10%.

Results: One hundred and ten patients received study treat-ment. Mean times to recovery of T1 to 10% and T1 to 90% weresignificantly faster in the rocuronium-sugammadex group (4.4and 6.2 min, respectively), as compared with the succinylcho-line group (7.1 and 10.9 min, respectively; all P < 0.001). Timedfrom sugammadex administration, the mean time to recoveryof T1 to 10%, T1 to 90%, and the train-of-four (T4/T1) ratio to 0.9was 1.2, 2.9, and 2.2 min, respectively. Reoccurrence of theblock was not observed. There were no serious adverse eventsrelated to study treatments.

Conclusion: Reversal of profound high-dose rocuronium-induced neuromuscular block (1.2 mg/kg) with 16 mg/kg sug-ammadex was significantly faster than spontaneous recoveryfrom 1 mg/kg succinylcholine.

SUCCINYLCHOLINE is a depolarizing neuromuscularblocking agent (NMBA) used for short-term muscle re-laxation, most often first-line to facilitate tracheal intu-bation. Because of its fast onset and short duration ofaction, it has considerable use in emergency situationswhere a neuromuscular block must be induced and theairway secured quickly to protect against aspiration ofgastric contents.1–3 A short duration of action is essentialin cases of a difficult airway where the patient cannot beintubated or ventilated and rapid restoration of sponta-neous respiration is crucial.2,4

Succinylcholine has the shortest duration of action ofall currently available NMBAs.5 At 1 mg/kg it typicallyprovides a complete block in approximately 1 min andrecovery in 6 to 9 min (first train-of-four twitch [T1] to10%) or 10 to 13 min (T1 to 90%).6–8 Succinylcholine isassociated with a variety of adverse events and contra-indications.9–15 Unfortunately, decades of efforts to de-velop a new nondepolarizing NMBA both safer andshorter-acting than succinylcholine have failed.16

The nondepolarizing NMBA rocuronium is also indi-cated to facilitate tracheal intubation during routine andrapid-sequence intubation, especially where succinyl-choline is contraindicated.** Succinylcholine (1 mg/kg)reliably provides excellent to acceptable intubating con-ditions, as compared with 0.6 to 0.7 mg/kg rocuronium,although no significant differences have been observedbetween 1 mg/kg succinylcholine 0.9 to 1.2 mg/kg rocu-ronium.2 Rocuronium (0.6 to 1.2 mg/kg) typically com-pletes a neuromuscular block in ! 2 min, as comparedwith ! 1 min on average for 1 mg/kg succinylcholine.17

However, higher doses of rocuronium have a long dura-tion of action; this is inappropriate in situations whererapid recovery of neuromuscular function is required.17

In addition, anticholinesterases readily expedite recov-ery from nondepolarizing block but are ineffective forthe reversal of a profound block, and present a signifi-cant side effect profile.12,18

A plausible new approach to both rapid onset and rapidrecovery of neuromuscular block might involve blockingwith high-dose rocuronium and reversal using high-dose

* Professor Emeritus, Department of Anesthesiology, David Geffen Schoolof Medicine at the University of California Los Angeles, Harbor/UCLA MedicalCenter, Torrance, California. † Professor of Clinical Anesthesiology, DavidGeffen School of Medicine at the University of California Los Angeles, RonaldReagan University of California Los Angeles Medical Center, Los Angeles,California. ‡ Associate Professor of Clinical Anesthesiology and Internal Med-icine; Director of Clinical Research; Chief, Division of Perioperative Medicine;University of Miami School of Medicine, Miami, Florida. § Professor and Head,University of British Columbia Department of Anesthesiology, Pharmacology andTherapeutics, St. Paul’s Hospital, Vancouver, British Columbia, Canada. ! Professorof Anesthesiology and Perioperative Medicine, Department of Anesthesiology,Oregon Health and Science University, Portland, Oregon. # Professor, Depart-ment of Anesthesiology and Pain Medicine, University of Texas M.D. AndersonCancer Center, Houston, Texas.

Received from the Department of Anesthesiology, David Geffen School ofMedicine at the University of California, Los Angeles and the Department ofAnesthesiology, Harbor University of California, Los Angeles Medical Center,Torrance, California. Submitted for publication June 11, 2008. Accepted forpublication November 20, 2008. This study was supported by Schering-Plough,Roseland, New Jersey; ClinicalTrials.gov number NCT00474253. Presented at theAmerican Society of Anesthesiologists 2007 Annual Meeting, San Francisco,California, October 13–17, 2007; and at the 14th World Congress of Anaesthe-siologists, Cape Town, South Africa, March 2–7, 2008.

Address correspondence to Dr. Lee: Department of Anesthesiology, DavidGeffen School of Medicine at University of California Los Angeles, Harbor/UCLAMedical Center, Box 10, 1000 W. Carson Street, Torrance, California [email protected]. This article may be accessed for personal use at no chargethrough the Journal Web site, www.anesthesiology.org.

** Zemuron (rocuronium bromide) SmPC, July 5, 2006. Available at: http://www.zemuron.com/authfiles/images/476_109852.pdf. Accessed April 1, 2008.

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Rocuronium and sugammadex for rapid sequence

induction of obstetric general anaesthesia

R. M. WILLIAMSON, S. MALLAIAH and P. BARCLAY

Liverpool Women’s Hospital, Liverpool, UK

Background: Many anaesthetists use rocuronium in placeof suxamethonium for rapid sequence induction (RSI).This is less common in obstetric anaesthesia as the dura-tion of action of an effective dose of rocuronium exceedsmost obstetric procedures. Sugammadex offers the possi-bility of rapidly reversing profound rocuronium neuro-muscular blockade at the end of surgery. We aimed todetermine whether rocuronium 1.2 mg/kg used for RSI inthe obstetric population would provide good intubatingconditions at 60 s and would be effectively reversed bysugammadex at the end of surgery.Methods: We present a prospective series of 18 patientswho received rocuronium 1.2mg/kg at induction of anaes-

thesia, monitored with a train-of-four ratio (TOF)-WatchSX

s

, and reversed using sugammadex 4mg/kg.Results: The mean (95% CI) onset time of rocuronium was71 (56–86) s, and the mean (95% CI) time to recovery of theTOF to ! 90%, after the administration of sugammadex4mg/kg at the end of surgery, was 86 (69–104) s.Conclusion: Rocuronium 1.2 mg/kg reversed by sugam-madex appears to be effective in the obstetric population.

Accepted for publication 26 February 2011

r 2011 The AuthorsActa Anaesthesiologica Scandinavicar 2011 The Acta Anaesthesiologica Scandinavica Foundation

GENERAL anaesthesia (GA) in late pregnancytraditionally involves rapid sequence induc-

tion (RSI) with thiopental and suxamethonium.1

Suxamethonium has a number of well-known dis-advantages,2 but no other neuromuscular blockerhas such favourable onset and offset characteris-tics. There is increasing interest in the use ofrocuronium, an aminosteroid non-depolarisingneuromuscular blocking drug, in place of suxa-methonium for RSI in the general3 and obstetricpopulation,4 with recent data suggesting that 36%of obstetric anaesthetists have used rocuronium atinduction of anaesthesia for a caesarean section.5

A large dose of rocuronium (1.2mg/kg) has beenshown to have a mean onset time of 55 s in non-pregnant subjects, which was similar to suxa-methonium (mean onset time 50 s) in the samepopulation.6 Other studies have shown a range inthe mean onset times of 65–95 s for rocuronium1.2mg/kg.7–9 However, at this high dose, the meanduration of action of rocuronium is 60–73min,6,7,10

which is significantly longer than most obstetricprocedures. Rocuronium has been used previously

in obstetric anaesthesia at a lower dose of 0.6mg/kg, which was shown to carry a 50% risk of poor orinadequate intubating conditions at 60 s followinginduction with thiopental 4mg/kg; increasing thethiopental dose to 6mg/kg and commencing tra-cheal intubation at 90 s improved intubating con-ditions to good or excellent in all patients.11

Sugammadex, a specifically designed g-cyclo-dextrin, can be used to rapidly and predictablyreverse even profound levels of rocuronium-in-duced neuromuscular blockade.12 Once sugamma-dex became available in our Trust, we introduced aguideline for the use of rocuronium 1.2mg/kg inobstetric surgery, followed by sugammadex 4mg/kg if the train-of-four (TOF) count was o2 at theend of surgery; if the TOF count was 2 or more,reversal was to be with neostigmine 2.5mg andglycopyrrolate 0.5mg.

We audited the use of rocuronium/sugammadexin our Trust with the aim of determining whetherrocuronium 1.2mg/kg provided satisfactory intu-bating conditions in an acceptable time frame andwhether sugammadex 4mg/kg reversed neuro-muscular blockade adequately in this population.We present audit data from the first 18 patientsto receive rocuronium 1.2mg/kg reversed by

Presented in part at the Obstetric Anaesthetists’ Association AnnualMeeting, Newcastle, UK, 2010.

1

Acta Anaesthesiol Scand 2011; ]]: 1–6Printed in Singapore. All rights reserved

r 2011 The AuthorsActa Anaesthesiologica Scandinavica

r 2011 The Acta Anaesthesiologica Scandinavica Foundation

ACTA ANAESTHESIOLOGICA SCANDINAVICA

doi: 10.1111/j.1399-6576.2011.02431.x


onset time

threatening)]; emergency instrumental delivery(two patients); and postpartum haemorrhage con-trol (one patient). All patients maintained a skintemperature of 435 1C with no supportive mea-sures. No patients had been treated with magne-sium sulphate.

The mean (SD; range) dose of rocuronium was 86(12.5; 60–100)mg. The mean (SD; 95% CI) time toablation of the TOF response after rocuronium was71 (33; 56–86) s, as demonstrated in Fig. 1.

Sixteen of the 18 patients had their tracheasintubated at 60 s at the first attempt; in the remain-ing two patients, intubation was successful at thesecond attempt. Intubating conditions were excel-lent in 12/18 and good in 6/18; none were rated aspoor or unacceptable.

Apgar scores were available for all 17 babies whowere delivered in the operating theatre, and at leastone cord blood pH was available for 16. Themedian Apgar score at 1min was 5.5 (range 1–9),with 12 babies having a score of o7. At 5min, themedian Apgar score was 9 (range 5–10), with threebabies having a score of o7. The mean umbilicalartery pH was 7.23, with two babies having a pHo7.2. Three babies were admitted to the neonatalunit; none of these babies needed to be ventilated.

The mean (SD; range) time from rocuroniumadministration to reversal drug administrationwas 62 (18; 46–119)min. At the end of surgery, all18 patients had a TOF of o2, with a mean (range)PTC of 3.7 (0–15) twitches, and all received sugam-madex 4mg/kg, with a mean (SD; range) dose of304 (62; 200–400)mg. The mean (95% CI) time toachieve a TOF ratio of ! 90% was 86 (69–104) s, asdemonstrated in Fig. 2. The correlation betweenPTC at administration of sugammadex and time toachieve a TOF ratio of ! 90% is shown in Fig. 3.

All patients’ tracheas were extubated promptlyonce neuromuscular function had returned, and no

patient had evidence of residual or re-curarisation.On follow-up on the ward at 12–24 h, sore throatwas reported by 6/18 and nausea and vomiting by3/18. One patient reported myalgia, although shehad had to return to theatre for treatment ofpostpartum haemorrhage, and received suxa-methonium.

Discussion

The mean onset time of 71 s using rocuronium1.2mg/kg in parturients in this study is withinthe range of 55–95 s recorded previously in non-pregnant patients.6–9 The wide range of onset timesshown in Fig. 1 is to be expected; while the meanonset times of suxamethonium 1.0mg/kg androcuronium 1.2mg/kg are similar, suxamethoniumonset consistently has a narrower range of valuesthan those for rocuronium.15 Previous work withrocuronium 0.6mg/kg found an onset time of 95 s,

Fig. 1. Time from the administration of rocuronium to ablation oftrain-of-four ratio response (s). Mean 70 s; 95% CI 55–86 s.

Fig. 2. Time from the administration of sugammadex to recoveryof train-of-four ratio ratio ! 90% (s). Mean 86 s; 95% CI 69–104 s.

Fig. 3. Correlation between post-tetanic count at administrationof sugammadex and time to recovery of train-of-four ratio ratio! 90% (s). Spearman’s r5 0.1461, P5 0.563.

Rocuronium and sugammadex in obstetrics

3Dienstag, 27. März 2012

decreasing the quality of the intubating conditionsor necessitating a second dose of suxamethoniumwith the attendant risk of bradycardia. With rocur-onium, multiple intubation attempts can occurwithout any deterioration of the intubating condi-tions. It has also been demonstrated that rocuro-nium 1.2mg/kg can be immediately reversed withsugammadex if required, albeit at a higher dose of16mg/kg. This results in a return of neuromuscu-lar function in 2.9min from the administration ofsugammadex, faster than the spontaneous offset ofsuxamethonium (10.9min).20

It is known that aminosteroid muscle relaxantscan have a longer duration of action in immediatelypostpartum patients,21 probably due to relativehepatic hypoperfusion in pregnancy as well asincreased protein binding and competition withsteroidal hormones for hepatic binding sites.16,22

Concern over this prolonged duration of actionmeans that there is a tendency to use the lowerdose of rocuronium 0.6mg/kg for RSI in preg-nancy, despite a rate of poor or inadequate intubat-ing conditions unless higher doses of an inductionagent are used.11 This is particularly relevant as therisk of failed intubation in the obstetric populationhas been estimated at as high as 1 : 27423; thus,ensuring adequate intubating conditions when GAis required is paramount. As we have shown thatsugammadex 4mg/kg allows the rapid and com-plete reversal of rocuronium in these patients,prolonged block should not be a barrier to usingan appropriate dose of rocuronium for obstetric RSIin the future.

Because we were observing everyday practice,our patients had a wide range of PTC at the end ofsurgery. We found that the mean time to recoveryof the TOF ratio to ! 90% after sugammadex was86 s. This is faster than the mean time reported innon-pregnant adults (174 s).12 However, the pa-tients in that study had their level of neuromuscu-lar blockade strictly controlled to a PTC of 1–2. Onepatient in our study had a PTC of zero at the end ofsurgery. We took the decision to administer sugam-madex 4mg/kg in any case, and monitor thepatient to ensure full recovery before extubation.This patient exhibited recovery to TOF ratio ! 90%in 57 s, and had no signs of re-curarisation in therecovery area. We found no correlation betweenPTC at administration of sugammadex and time toTOF ratio ! 90% in our patients; hence, the differ-ence may be explained by the increased cardiacoutput of pregnancy. This compares with work thatsuggests that a decreased cardiac output in the

elderly contributes to a longer time to recover toTOF ratio ! 90% following sugammadex admin-istration.24

There are clear arguments for substituting rocur-onium for suxamethonium to reduce the incidenceof suxamethonium-related side effects – principallymyalgia and an incidence of anaphylaxis of 1 : 5000.The incidence of allergy to sugammadex is notknown, and although the United States Food andDrug Administration declined a licence for sugam-madex on the basis of concerns about hypersensi-tivity,* there are as yet no reports of anaphylaxis tothis drug. The risk of sensitivity to rocuronium isthought to be similar to atracurium, but less thansuxamethonium.25

We have shown that time to maximum neuromus-cular block after rocuronium 1.2mg/kg in the ob-stetric population, as assessed by research-standardneuromuscular monitoring, seems to be within therange expected from studies in non-pregnant pa-tients. This rocuronium dose allows intubation ofthe trachea within 60 s and can be reversed rapidlyand fully with sugammadex at the end of surgery.It should be noted that none of the patients westudied had been treated with magnesium sul-phate; such patients should be closely monitoredduring neuromuscular blockade due to the risk ofprolongation of action of muscle relaxant drugs.

We conclude that the use of rocuronium in doseso1.2mg/kg cannot be recommended in the obste-tric population now that sugammadex is available.We also recommend that the use of rocuronium inobstetric anaesthesia be monitored by a neuromus-cular monitoring device, to allow the assessment ofdepth of neuromuscular blockade at the end ofsurgery. Controlled studies comparing rocuro-nium/sugammadex with suxamethonium for RSIin obstetric anaesthesia are urgently required.

Acknowledgements

We thank Professor Jennifer Hunter for her advice on theconduct of the audit and for her valuable critique of themanuscript.Conflict of interest: The TOF-Watch SX

s

device was supplied foreducational purposes by Schering Plough, UK, who alsoprovided an educational grant to allow DrWilliamson to attendEuroanaesthesia 2010 in Helsinki. They had no involvement inthe design of the audit and all drugs used were purchased byour department.

*http://www.fda.gov/ohrms/dockets/ac/08/transcripts/2008-4346t1-part2.pdf [accessed 9 February 2011].

Rocuronium and sugammadex in obstetrics

5

Rocuronium and sugammadex for rapid sequence

induction of obstetric general anaesthesia

R. M. WILLIAMSON, S. MALLAIAH and P. BARCLAY

Liverpool Women’s Hospital, Liverpool, UK

Background: Many anaesthetists use rocuronium in placeof suxamethonium for rapid sequence induction (RSI).This is less common in obstetric anaesthesia as the dura-tion of action of an effective dose of rocuronium exceedsmost obstetric procedures. Sugammadex offers the possi-bility of rapidly reversing profound rocuronium neuro-muscular blockade at the end of surgery. We aimed todetermine whether rocuronium 1.2 mg/kg used for RSI inthe obstetric population would provide good intubatingconditions at 60 s and would be effectively reversed bysugammadex at the end of surgery.Methods: We present a prospective series of 18 patientswho received rocuronium 1.2mg/kg at induction of anaes-

thesia, monitored with a train-of-four ratio (TOF)-WatchSX

s

, and reversed using sugammadex 4mg/kg.Results: The mean (95% CI) onset time of rocuronium was71 (56–86) s, and the mean (95% CI) time to recovery of theTOF to ! 90%, after the administration of sugammadex4mg/kg at the end of surgery, was 86 (69–104) s.Conclusion: Rocuronium 1.2 mg/kg reversed by sugam-madex appears to be effective in the obstetric population.

Accepted for publication 26 February 2011

r 2011 The AuthorsActa Anaesthesiologica Scandinavicar 2011 The Acta Anaesthesiologica Scandinavica Foundation

GENERAL anaesthesia (GA) in late pregnancytraditionally involves rapid sequence induc-

tion (RSI) with thiopental and suxamethonium.1

Suxamethonium has a number of well-known dis-advantages,2 but no other neuromuscular blockerhas such favourable onset and offset characteris-tics. There is increasing interest in the use ofrocuronium, an aminosteroid non-depolarisingneuromuscular blocking drug, in place of suxa-methonium for RSI in the general3 and obstetricpopulation,4 with recent data suggesting that 36%of obstetric anaesthetists have used rocuronium atinduction of anaesthesia for a caesarean section.5

A large dose of rocuronium (1.2mg/kg) has beenshown to have a mean onset time of 55 s in non-pregnant subjects, which was similar to suxa-methonium (mean onset time 50 s) in the samepopulation.6 Other studies have shown a range inthe mean onset times of 65–95 s for rocuronium1.2mg/kg.7–9 However, at this high dose, the meanduration of action of rocuronium is 60–73min,6,7,10

which is significantly longer than most obstetricprocedures. Rocuronium has been used previously

in obstetric anaesthesia at a lower dose of 0.6mg/kg, which was shown to carry a 50% risk of poor orinadequate intubating conditions at 60 s followinginduction with thiopental 4mg/kg; increasing thethiopental dose to 6mg/kg and commencing tra-cheal intubation at 90 s improved intubating con-ditions to good or excellent in all patients.11

Sugammadex, a specifically designed g-cyclo-dextrin, can be used to rapidly and predictablyreverse even profound levels of rocuronium-in-duced neuromuscular blockade.12 Once sugamma-dex became available in our Trust, we introduced aguideline for the use of rocuronium 1.2mg/kg inobstetric surgery, followed by sugammadex 4mg/kg if the train-of-four (TOF) count was o2 at theend of surgery; if the TOF count was 2 or more,reversal was to be with neostigmine 2.5mg andglycopyrrolate 0.5mg.

We audited the use of rocuronium/sugammadexin our Trust with the aim of determining whetherrocuronium 1.2mg/kg provided satisfactory intu-bating conditions in an acceptable time frame andwhether sugammadex 4mg/kg reversed neuro-muscular blockade adequately in this population.We present audit data from the first 18 patientsto receive rocuronium 1.2mg/kg reversed by

Presented in part at the Obstetric Anaesthetists’ Association AnnualMeeting, Newcastle, UK, 2010.

1

Acta Anaesthesiol Scand 2011; ]]: 1–6Printed in Singapore. All rights reserved

r 2011 The AuthorsActa Anaesthesiologica Scandinavica

r 2011 The Acta Anaesthesiologica Scandinavica Foundation

ACTA ANAESTHESIOLOGICA SCANDINAVICA

doi: 10.1111/j.1399-6576.2011.02431.x


Rapid sequence induction and intubationwith rocuronium–sugammadex compared withsuccinylcholine: a randomized trialM. K. Sørensen1*, C. Bretlau2, M. R. Gatke2, A. M. Sørensen1 and L. S. Rasmussen1

1 Department of Anaesthesia, Centre of Head and Orthopaedics, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, 2100Copenhagen, Denmark2 Department of Anaesthesiology, Copenhagen University Hospital, Herlev Hospital, Herlev Ringvej 75, 2730 Herlev, Denmark

* Corresponding author. E-mail: [email protected]

Editor’s key points

† Succinylcholine isrecommended for rapidsequence inductionbecause of its quick onsetand offset of actions.

† The offset of action ofsuccinylcholine wascompared with that ofthe rocuronium–sugammadex sequence.

† Sixty-one patients werestudied in a randomizedand blinded manner.

† Importantly, therocuronium–sugammadex sequencehad significantly quickeroffset of neuromuscularblocking agent effectcompared withsuccinylcholine.

Background. An unanticipated difficult airway may arise during rapid sequence inductionand intubation (RSII). The aim of the trial was to assess how rapidly spontaneousventilation could be re-established after RSII. We hypothesized that the time period fromtracheal intubation to spontaneous ventilation would be shorter with rocuronium–sugammadex than with succinylcholine.

Methods. This randomized and patient- and observer-blinded trial was approved by theregional Ethics Committee and the Danish Medicines Agency. We included electivesurgical patients undergoing general anaesthesia for RSII using alfentanil (10 mg kg21),propofol (2 mg kg21), and either succinylcholine (1 mg kg21) or rocuronium (1 mg kg21).Sugammadex (16 mg kg21) was given in the rocuronium group after tracheal intubation.The primary endpoint was the time from correct placement of the tracheal tube tospontaneous ventilation, defined as a respiratory rate of more than 8 bpm and a tidalvolume of at least 3 ml kg21 for 30 s.

Results. We included 61 patients; of whom, 55 were evaluated for the primary endpoint.The median time from tracheal intubation to spontaneous ventilation was 406 s withsuccinylcholine and 216 s with rocuronium–sugammadex (P ! 0.002). The median timefrom tracheal intubation to 90% recovery of the first twitch in train-of-four (T1 90%) was518 s with succinylcholine and 168 s with rocuronium–sugammadex (P , 0.0001).Intubation conditions and time to tracheal intubation were not significantly different.

Conclusions. RSII with rocuronium followed by reversal with sugammadex allowed earlierre-establishment of spontaneous ventilation than with succinylcholine.

Keywords: anaesthesia, intravenous; intubation, intratracheal; neuromuscular block

Accepted for publication: 23 November 2011

Rapid sequence induction and intubation (RSII) is performedwhen there is an increased risk of pulmonary aspiration ofgastric contents. RSII consists of the following: optimal posi-tioning of the patient, pre-oxygenation, injection of an opioidand a hypnotic i.v., injection of a fast-acting neuromuscularblocking agent (NMBA), cricoid pressure, and trachealintubation.1 – 3

Succinylcholine has been for a long time the NMBA ofchoice for RSII, because of quick onset along with excellentintubation conditions.4 However, it has been desirable toidentify an alternative to succinylcholine because of its side-effects and the risk of delayed recovery of neuromuscularfunction. Spontaneous recovery of a succinylcholine-inducedneuromuscular block may take too long to avoid desatur-ation in a ‘cannot intubate, cannot ventilate’ situation. Insome patients, the hydrolysis of succinylcholine may be

severely impaired as a result of genetic or acquired lowcholinesterase activity.5 6

As an alternative to succinylcholine, the non-depolarizingNMBA rocuronium can be used for RSII.7 The onset time ofrocuronium 1 mg kg21 is around 60 s.7 Its duration ofaction is, however, 122 (33) min [from injection to recoveryof first twitch of train-of-four (TOF) to 75% of baseline] fora single bolus dose of 0.9 mg kg21.8 A new antagonist,sugammadex, binds the rocuronium molecules in a 1:1ratio 9 without having an effect on the plasma cholinesteraseor on any receptor system in the human body.10 – 14 Evenprofound neuromuscular block with rocuronium can bequickly antagonized with sugammadex.15

The aim of this trial was to assess the time from verifiedcorrect tracheal tube placement after RSII until regular andspontaneous ventilation was re-established. In addition, we

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Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.

Rapid sequence induction in obstetrics revisitedLisa M. Sharpa and David M. Levyb

IntroductionIt is half a century since the regimen of thiopental,succinylcholine (SCh), tracheal intubation and unsupple-mented nitrous oxide/oxygen was first promoted forCaesarean section [1].

Although the induction drug sequence has endured (albeitwith an increased dose of thiopental), it is now acceptedthat sufficient vapour should always be administered,before and after birth of the baby, to prevent explicitawareness. Controversy surrounds cricoid force and airwaymanagement strategies. The introduction of sugammadexraises the possibility of using a large dose of rocuronium toallow as fast an onset of neuromuscular blockade (NMB) asthat afforded by SCh [2!]. In the rare event of a ‘can’tintubate, can’t ventilate’ scenario, profound NMB wouldbe swiftly reversed by sugammadex 16 mg/kg.

Historical basis of obstetric rapid sequenceinductionA technique of intravenous (i.v.) induction, NMB andtracheal intubation for Caesarean section was describedby Hamer Hodges et al. [1] in 1959. Thiopental, SChand nitrous oxide/oxygen resulted in the shortest timesto babies’ sustained respiration and crying, comparedwith anaesthetic regimens in which mothers receivedtrichloroethylene, cyclopropane or diethyl ether. Certainelements of rapid sequence induction (RSI) were absent:cricoid force was not applied (Sellick had yet to describehis manoeuvre) and there was a period of bag and maskventilation between induction and intubation. The noveluse of SCh for Caesarean section was advocated on the

grounds that its rapid maternal offset reduced the chanceof neonatal curarization, compared with the only twoalternative neuromuscular blockers, gallamine and tubo-curarine. The notion that recovery from SCh mightconceivably be advantageous for the mother in the eventof airway problems did not appear to be entertained.

The salient characteristics of RSI were delineated byStept and Safar in 1970 [3].

– Preoxygenation– Predetermined doses of thiopental and SCh– Cricoid force– Avoidance of ventilation by bag and mask– Tracheal intubation

It has been noted that the number of maternal deaths in theUK Confidential Enquiries attributable to anaesthesiavirtually doubled in the period corresponding to thewidespread replacement of mask and ether by RSI inthe early 1960s [4]. Scott [5] highlighted the apparentincreased incidence of death due to Mendelson’ssyndrome and failed intubation secondary to SCh and RSI.

A rigorous Canadian evidence-based clinical update hasexamined, in wide-ranging studies, the components ofRSI. No evidence was found for decreased incidence ofaspiration with RSI – the raison d’etre for continuing topractise the technique [6!]. Pandit [7!] has recentlycommented that RSI enjoys the ‘weight of historicalauthority’; despite a conspicuous lack of supportive evi-dence, the technique is embraced for Caesarean sectionby the UK National Institute for Health and ClinicalExcellence (NICE) [8].

aNottingham and East Midlands School of Anaesthesiaand bNottingham University Hospitals NHS Trust,Nottingham, UK

Correspondence to Dr D.M. Levy, AnaestheticsDepartment, Queen’s Medical Centre Campus,Nottingham University Hospitals NHS Trust,Nottingham, NG7 2UH, UKFax: +44 115 9783891; e-mail: [email protected]

Current Opinion in Anaesthesiology 2009,22:357–361

Purpose of reviewThe regimen of thiopental, succinylcholine (SCh) and unsupplemented nitrous oxide/oxygen for Caesarean section was first introduced 50 years ago. This review examineswhich elements have endured, what has changed, and how practice might alter in thevery near future.Recent findingsSugammadex, a cyclodextrin, is capable of rapid reversal of profound rocuroniumneuromuscular blockade.SummaryIt is now feasible that SCh might be replaced with a high-dose rocuronium–sugammadex combination.

Keywordsanaesthetics, neuromuscular blockade, rocuronium, succinylcholine, sugammadex

Curr Opin Anaesthesiol 22:357–361! 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins0952-7907

0952-7907 ! 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins DOI:10.1097/ACO.0b013e3283294c4a


Rapid sequence induction in obstetrics revisitedLisa M. Sharpa and David M. Levyb

IntroductionIt is half a century since the regimen of thiopental,succinylcholine (SCh), tracheal intubation and unsupple-mented nitrous oxide/oxygen was first promoted forCaesarean section [1].

Although the induction drug sequence has endured (albeitwith an increased dose of thiopental), it is now acceptedthat sufficient vapour should always be administered,before and after birth of the baby, to prevent explicitawareness. Controversy surrounds cricoid force and airwaymanagement strategies. The introduction of sugammadexraises the possibility of using a large dose of rocuronium toallow as fast an onset of neuromuscular blockade (NMB) asthat afforded by SCh [2!]. In the rare event of a ‘can’tintubate, can’t ventilate’ scenario, profound NMB wouldbe swiftly reversed by sugammadex 16 mg/kg.

Historical basis of obstetric rapid sequenceinductionA technique of intravenous (i.v.) induction, NMB andtracheal intubation for Caesarean section was describedby Hamer Hodges et al. [1] in 1959. Thiopental, SChand nitrous oxide/oxygen resulted in the shortest timesto babies’ sustained respiration and crying, comparedwith anaesthetic regimens in which mothers receivedtrichloroethylene, cyclopropane or diethyl ether. Certainelements of rapid sequence induction (RSI) were absent:cricoid force was not applied (Sellick had yet to describehis manoeuvre) and there was a period of bag and maskventilation between induction and intubation. The noveluse of SCh for Caesarean section was advocated on the

grounds that its rapid maternal offset reduced the chanceof neonatal curarization, compared with the only twoalternative neuromuscular blockers, gallamine and tubo-curarine. The notion that recovery from SCh mightconceivably be advantageous for the mother in the eventof airway problems did not appear to be entertained.

The salient characteristics of RSI were delineated byStept and Safar in 1970 [3].

– Preoxygenation– Predetermined doses of thiopental and SCh– Cricoid force– Avoidance of ventilation by bag and mask– Tracheal intubation

It has been noted that the number of maternal deaths in theUK Confidential Enquiries attributable to anaesthesiavirtually doubled in the period corresponding to thewidespread replacement of mask and ether by RSI inthe early 1960s [4]. Scott [5] highlighted the apparentincreased incidence of death due to Mendelson’ssyndrome and failed intubation secondary to SCh and RSI.

A rigorous Canadian evidence-based clinical update hasexamined, in wide-ranging studies, the components ofRSI. No evidence was found for decreased incidence ofaspiration with RSI – the raison d’etre for continuing topractise the technique [6!]. Pandit [7!] has recentlycommented that RSI enjoys the ‘weight of historicalauthority’; despite a conspicuous lack of supportive evi-dence, the technique is embraced for Caesarean sectionby the UK National Institute for Health and ClinicalExcellence (NICE) [8].

aNottingham and East Midlands School of Anaesthesiaand bNottingham University Hospitals NHS Trust,Nottingham, UK

Correspondence to Dr D.M. Levy, AnaestheticsDepartment, Queen’s Medical Centre Campus,Nottingham University Hospitals NHS Trust,Nottingham, NG7 2UH, UKFax: +44 115 9783891; e-mail: [email protected]


Purpose of reviewThe regimen of thiopental, succinylcholine (SCh) and unsupplemented nitrous oxide/oxygen for Caesarean section was first introduced 50 years ago. This review examineswhich elements have endured, what has changed, and how practice might alter in thevery near future.Recent findingsSugammadex, a cyclodextrin, is capable of rapid reversal of profound rocuroniumneuromuscular blockade.SummaryIt is now feasible that SCh might be replaced with a high-dose rocuronium–sugammadex combination.

Keywordsanaesthetics, neuromuscular blockade, rocuronium, succinylcholine, sugammadex


0952-7907 ! 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins DOI:10.1097/ACO.0b013e3283294c4a

It might be expected that the mass of rocuronium transferred across the placenta will be broadly proportional to the maternal dose;

it is uncertain whether the fraction of 1.2 mg/kg transferred in the event of protracted surgical delivery is innocuous.


Preoxygenation




Incision


cord clamping








Preeclampsia and anaesthesiaWiebke Gogarten

IntroductionHypertensive disorders of pregnancy are a multisystemdisorder with heterogeneous presentation and ill-definedaetiology. Preeclampsia is one of the leading causes ofmaternal morbidity and mortality and occurs in 3–5% ofall pregnancies worldwide. It is associated with hyper-tension (preeclampsia >140 mmHg, severe preeclampsia>160 mmHg) and proteinuria (>300 mg/24 h) and may beaccompanied by hepatic, renal and clotting disorders.Maternal and neonatal outcome depend on gestationalage at onset, severity of the disease and presence ofpreexisting medical conditions. Outcome is usually muchbetter in mild cases with late onset beyond 36 weeksof gestation.

Independent risk factors include low maternal age, higherBMI, chronic hypertension, insulin resistance and pree-clampsia during previous pregnancies. Factors involvedinclude abnormal maternal–placental angiogenesis andendothelial dysfunction. This may lead to vasoconstric-tion, arterial hypertension and organ dysfunction. Deliveryis the only maternal cure, and whether early delivery orexpectant management is favoured depends on gestationalage, foetal status and maternal compromise. However, inearly-onset preeclampsia before 27 weeks of gestation,expectant management may lead to deterioration of foetaland maternal status. Bombrys et al. [1] reported a neonatalmortality rate of 57%, accompanied by a maternal com-plication rate of 30–67%. The leading causes of maternalmorbidity were haemolytic anaemia, elevated liver

Department of Anaesthesiology and Intensive Care,University of Muenster, Muenster, Germany

Correspondence to Wiebke Gogarten, Department ofAnaesthesiology and Intensive Care, University ofMuenster, Albert-Schweitzer-Street 33, D-48149Muenster, GermanyTel: +49 251 8347258; fax: +49 251 8348667;e-mail: [email protected]


Purpose of reviewThe most recent findings on preeclampsia with a focus on maternal mortality,haemodynamic changes, clotting disorders and anaesthesia are reviewed.Recent findingsPreeclampsia is a major cause of maternal morbidity and mortality. Cerebralhaemorrhage is the single most common cause of maternal death in preeclampsia andcurrently far outnumbers pulmonary oedema. Although there was a focus on diastolicpressure in the past, the present recommendations of the National Enquiries intoMaternal Death advocate treatment of systolic blood pressures above 160 mmHg inorder to avoid intracranial bleeding. Noninvasive monitoring techniques such as pulsewave analysis and echocardiography have provided new insights into thehaemodynamic changes of preeclampsia and corroborated previous findings. In early-onset preeclampsia, the most common haemodynamic features includevasoconstriction, low cardiac output and low filling pressures. Neuraxial anaesthesiaaids in providing stable haemodynamics, the incidence of hypotension and the need forvasopressors are reduced compared with healthy parturients, and cardiac output isunchanged. With cautious fluid administration, the risk of pulmonary oedema seemsnegligible. In order to avoid spinal epidural haematoma in the presence ofthrombocytopenia, spinal anaesthesia may afford the best risk–benefit analysis. Itremains open to question whether thromboelastography will aid in guiding treatment inthe future.SummaryCerebral haemorrhage is the major cause of maternal mortality in preeclampsia and anyincreases in maternal blood pressure above 160 mmHg or at induction of generalanaesthesia should be treated. Traditional rapid sequence induction is, therefore, bestavoided; neuraxial anaesthesia is the technique of choice.

Keywordscerebral haemorrhage, cerebral oedema, combined spinal–epidural anaesthesia,echocardiography, eclampsia, epidural anaesthesia, preeclampsia, rapid sequenceinduction, spinal anaesthesia, thrombelastography


0952-7907 ! 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins DOI:10.1097/ACO.0b013e32832a1d05Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.

Preeclampsia and anaesthesiaWiebke Gogarten

IntroductionHypertensive disorders of pregnancy are a multisystemdisorder with heterogeneous presentation and ill-definedaetiology. Preeclampsia is one of the leading causes ofmaternal morbidity and mortality and occurs in 3–5% ofall pregnancies worldwide. It is associated with hyper-tension (preeclampsia >140 mmHg, severe preeclampsia>160 mmHg) and proteinuria (>300 mg/24 h) and may beaccompanied by hepatic, renal and clotting disorders.Maternal and neonatal outcome depend on gestationalage at onset, severity of the disease and presence ofpreexisting medical conditions. Outcome is usually muchbetter in mild cases with late onset beyond 36 weeksof gestation.

Independent risk factors include low maternal age, higherBMI, chronic hypertension, insulin resistance and pree-clampsia during previous pregnancies. Factors involvedinclude abnormal maternal–placental angiogenesis andendothelial dysfunction. This may lead to vasoconstric-tion, arterial hypertension and organ dysfunction. Deliveryis the only maternal cure, and whether early delivery orexpectant management is favoured depends on gestationalage, foetal status and maternal compromise. However, inearly-onset preeclampsia before 27 weeks of gestation,expectant management may lead to deterioration of foetaland maternal status. Bombrys et al. [1] reported a neonatalmortality rate of 57%, accompanied by a maternal com-plication rate of 30–67%. The leading causes of maternalmorbidity were haemolytic anaemia, elevated liver

Department of Anaesthesiology and Intensive Care,University of Muenster, Muenster, Germany

Correspondence to Wiebke Gogarten, Department ofAnaesthesiology and Intensive Care, University ofMuenster, Albert-Schweitzer-Street 33, D-48149Muenster, GermanyTel: +49 251 8347258; fax: +49 251 8348667;e-mail: [email protected]


Purpose of reviewThe most recent findings on preeclampsia with a focus on maternal mortality,haemodynamic changes, clotting disorders and anaesthesia are reviewed.Recent findingsPreeclampsia is a major cause of maternal morbidity and mortality. Cerebralhaemorrhage is the single most common cause of maternal death in preeclampsia andcurrently far outnumbers pulmonary oedema. Although there was a focus on diastolicpressure in the past, the present recommendations of the National Enquiries intoMaternal Death advocate treatment of systolic blood pressures above 160 mmHg inorder to avoid intracranial bleeding. Noninvasive monitoring techniques such as pulsewave analysis and echocardiography have provided new insights into thehaemodynamic changes of preeclampsia and corroborated previous findings. In early-onset preeclampsia, the most common haemodynamic features includevasoconstriction, low cardiac output and low filling pressures. Neuraxial anaesthesiaaids in providing stable haemodynamics, the incidence of hypotension and the need forvasopressors are reduced compared with healthy parturients, and cardiac output isunchanged. With cautious fluid administration, the risk of pulmonary oedema seemsnegligible. In order to avoid spinal epidural haematoma in the presence ofthrombocytopenia, spinal anaesthesia may afford the best risk–benefit analysis. Itremains open to question whether thromboelastography will aid in guiding treatment inthe future.SummaryCerebral haemorrhage is the major cause of maternal mortality in preeclampsia and anyincreases in maternal blood pressure above 160 mmHg or at induction of generalanaesthesia should be treated. Traditional rapid sequence induction is, therefore, bestavoided; neuraxial anaesthesia is the technique of choice.

Keywordscerebral haemorrhage, cerebral oedema, combined spinal–epidural anaesthesia,echocardiography, eclampsia, epidural anaesthesia, preeclampsia, rapid sequenceinduction, spinal anaesthesia, thrombelastography


0952-7907 ! 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins DOI:10.1097/ACO.0b013e32832a1d05


Spinal epidural haematomaAlthough spinal epidural haematoma is more commonthan previously thought it is rare in the obstetric popu-lation. Moen et al. [24] reported spinal epidural haema-tomas over a 10-year period in Sweden, covering1 260 000 spinal and 450 000 epidural blockades. Theincidence was 1 : 5400 in orthopaedic patients as opposedto 1 : 200 000 in obstetrics. Both obstetric epidural hae-matomas occurred in parturients with HELLP syndrome,a condition known for increased bleeding. A nationalaudit from the United Kingdom covering more than700 000 neuraxial blocks showed only five epidural hae-matomas in the overall population including obstetrics[25!!]. Of these, none occurred during spinal anaesthesia.The data again demonstrated that neuraxial blockade ismuch safer in pregnant patients than in other popu-lations. In thrombocytopenic patients, the trend in plate-let count may be more important than actual plateletnumbers, with a lowest count to perform neuraxial block-ade safely currently not identified. As spinal anaesthesiais associated with a significantly reduced risk of epiduralhaematoma compared with epidural anaesthesia, spinalanaesthesia should be preferred in this patient popu-lation. A survey among anaesthesiologists showed thata platelet count below 65" 109/l was considered anabsolute contraindication for epidural anaesthesia by64.5% of the respondents, and an absolute contraindica-tion for spinal anaesthesia by 51.3% of the respondents,indicating that spinal anaesthesia was preferred in thepresence of thrombocytopenia [26]. If additional antipla-telet drugs or heparins are administered, adherence tonational guidelines is recommended [27].

Neuraxial anaesthesiaGiven that failure to vasodilate is a common factor inpreeclampsia, neuraxial blockade during labour anddelivery appears to be a logical choice. Most studies inpatients with preeclampsia attest to the safety of thisapproach. Aya et al. [28] demonstrated an almost twotimes lower incidence of hypotension and reduced vaso-pressor requirements during spinal anaesthesia for cesar-ean delivery compared with healthy parturients. Morerecently, Dyer et al. [29!], using lithium dilution cardiacoutput monitoring in severe preeclampsia, showed thatneither spinal anaesthesia nor treatment of hypotensionwith modest doses of phenylephrine reduces maternalcardiac output during caesarean section, further support-ing the safety in this patient population. Advantages ofspinal anaesthesia include the ease of technique and afaster onset, making spinal anaesthesia suitable for urgentdelivery. Although epidural anaesthesia provides mod-estly superior haemodynamic stability, there are nodifferences between the two techniques in neonatal out-come [30]. On the basis of these results spinal anaesthesia

may be the method of choice in preeclampsia due to thedecreased risk of spinal epidural haematoma.

General anaesthesiaTraditional rapid sequence induction is associated withsignificant increases in maternal blood pressure. Althoughthis is well tolerated by healthy parturients, it may bedetrimental in preeclampsia or cardiovascular disease. Inthe most recent Enquiries into Maternal Death at leasttwo cases of intracerebral haemorrhage in preeclampsiawere attributed to intubation [7!!]. One of the keylearning points was that the anaesthesiologist shouldbe given enough time to prevent pressure responses ofintubation independent of reasons for imminent foetaldelivery. Several drugs have been successfully applied. Abolus of magnesium or remifentanil reliably preventspressure responses without foetal compromise [16,31].Remifentanil is devoid of prolonged neonatal respiratorydepression with sustained respiration achieved after 75 s,indicating that only a brief period of mask ventilation isrequired [31].

A difficult airway must always be anticipated. The inci-dence of failed intubation in obstetrics is 1: 274 and maybe further aggravated by a trial of labour due to fluidretention [32!,33!]. Whether women with preeclampsiaare more susceptible to these changes is currentlyunknown.

Owing to the risk of failed intubation and haemodynamicconsequences of intubation, general anaesthesia shouldbe limited to parturients with severe coagulation dis-orders, HELLP syndrome, pulmonary oedema, signs orsymptoms of cerebral oedema or other contraindicationsagainst regional anaesthesia.

ConclusionPreeclampsia is a multisystem disorder that occurs in2–5% of all pregnancies and accounts for significantmaternal and foetal morbidity and mortality. The onlyreasonable maternal cure is foetal delivery. In cases ofmaternal and foetal well being, expectant management toallow foetal growth and lung maturation may be a reason-able alternative. Haemodynamic changes in early-onsetpreeclampsia consists in the majority of vasoconstrictionwith arterial hypertension, low filling pressures and lowcardiac output. The most devastating complication ofpreeclampsia is cerebral haemorrhage, accounting for mostcases of maternal mortality. Although there was a focus ondiastolic pressure in the past, the present recommen-dations of the National Enquiries into Maternal Deathadvocate treatment of systolic blood pressures above160 mmHg in order to avoid cerebral haemorrhage [7!!].If general anaesthesia cannot be avoided due to clotting

350 Obstetric and gynecological anesthesia


Dose-related attenuation of cardiovascular responses totracheal intubation by intravenous remifentanil bolus insevere pre-eclamptic patients undergoing Caesarean deliveryB. Y. Park 1, C. W. Jeong 1, E. A. Jang 1, S. J. Kim 1, S. T. Jeong 1, M. H. Shin 2, J. Lee 3 and K. Y. Yoo 1*1 Department of Anaesthesiology and Pain Medicine, 2 Department of Preventive Medicine, and 3 Department of Physiology, ChonnamNational University Medical School, 8 Hak-dong, Gwangju 501-190, Republic of Korea

* Corresponding author. E-mail: [email protected]

Key points

† The dose of i.v.remifentanil forattenuation ofhaemodynamicresponses to trachealintubation was studied inpre-eclamptic patientsundergoing Caesareandelivery.

† Both 0.5 and 1.0 mg kg21

doses effectivelyattenuatedcardiovascular responsesto intubation in severepre-eclamptics, but thehigher dose caused morehypotensionpost-intubation.

Background. The optimal dose of remifentanil to attenuate the cardiovascular responses totracheal intubation in pre-eclamptic patients undergoing Caesarean delivery under generalanaesthesia has not been established. We compared the effects of two low doses ofremifentanil on the cardiovascular responses to tracheal intubation and neonataloutcomes.

Methods. Forty-eight women with severe pre-eclampsia were randomly assigned to receiveeither remifentanil 0.5 mg kg21 (R0.5 group, n!24) or 1 mg kg21 (R1.0 group, n!24) over30 s before induction of anaesthesia using thiopental 5 mg kg21 and succinylcholine 1.5mg kg21. Systolic arterial pressure (SAP), heart rate (HR), and plasma catecholamineconcentrations were measured. Neonatal effects were assessed using Apgar scores andumbilical cord blood gas analysis.

Results. SAP was decreased by induction of anaesthesia and increased by trachealintubation in both groups. The peak SAP after intubation was greater in the R0.5 groupthan in the R1.0 group, whereas it did not exceed baseline values in either group. HRincreased significantly above baseline in both groups with no significant differencesbetween the groups. Three subjects in the R1.0 group received ephedrine due tohypotension (SAP,90 mm Hg). Norepinephrine concentrations remained unaltered afterintubation and increased significantly at delivery with no significant differences betweenthe groups. Neonatal Apgar scores and umbilical arterial and venous pH and blood gasvalues were comparable between the groups.

Conclusions. Both doses of remifentanil effectively attenuated haemodynamic responses totracheal intubation with transient neonatal respiratory depression in pre-eclamptic patientsundergoing Caesarean delivery under general anaesthesia. The 1.0 mg kg21 dose wasassociated with hypotension in three of 24 subjects.

Keywords: anaesthetic techniques; induction; anaesthetic techniques; laryngoscopy;cardiovascular system; effects; complications; intubation tracheal; opioids; remifentanil

Accepted for publication: 1 September 2010

Laryngoscopy and tracheal intubation usually increasearterial pressure and heart rate (HR).1 In women withpregnancy-induced hypertension, the cardiovascularresponse to tracheal intubation is exaggerated.2 3 Theabrupt increase in arterial pressure, although transient, canlead to cerebral oedema and haemorrhage, and cardiacfailure with pulmonary oedema, increasing morbidity andmortality in both the mother and child.4 In addition, anincrease in maternal plasma catecholamine concentrationsat the induction of anaesthesia for Caesarean delivery cancause uteroplacental vasoconstriction and hence adverselyaffect the neonate.5 – 8 Therefore, close control of stressresponses during induction of anaesthesia for Caesarean

delivery can have both fetal and maternal benefits in pre-eclamptic patients.

Remifentanil has been shown to blunt cardiovascularresponses to intubation with minimal neonatal respiratorydepression in healthy pregnant patients9 and also in severepre-eclamptics.10 However, remifentanil 1 mg kg21 givenimmediately before intubation produced severe hypotensionin two (9.5%) of 21 severe pre-eclamptic patients,10

suggesting that the dosage of remifentanil should be titratedto improve the risk/benefit ratio from a maternal perspective.Certainly, maternal hypotension, which may compromiseuteroplacental perfusion, is as much of a concern as elevatedarterial pressure in pre-eclamptic patients.

British Journal of Anaesthesia 106 (1): 82–7 (2011)Advance Access publication 14 October 2010 . doi:10.1093/bja/aeq275


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by Scheffe’s post hoc testing as required. Categorical datawere analysed using Fisher’s exact test. Other data werecompared between the groups using unpaired Student’st-test. Baseline values were taken as those values measuredat the time 22 min. A P-value of ,0.05 was considered stat-istically significant.

ResultsAmong 55 subjects initially enrolled in the study, seven wereexcluded: four due to patient refusal, one due to maternalheart disease, and two due to a failure of establishment ofan arterial line. The resultant 48 subjects were randomizedin equal numbers to the two groups and completed thestudy without protocol violations (Fig. 1). There were nodifferences between the groups with respect to maternalage, weight, height, gestational age, amount of blood loss,surgical characteristics, or incidence of MgSO4 and hydrala-zine therapy (Table 1). Ephedrine was administered to threesubjects (12.5%) in the R1.0 group and none in the R0.5group for the treatment of hypotension (SAP,90 mm Hg).

Baseline SAP and HR did not significantly differ betweenthe groups. SAP decreased significantly after induction ofanaesthesia and increased after intubation (P,0.05 com-pared with pre-intubation). The magnitude of increases wasgreater in the R0.5 group [28 (24) mm Hg] than in the R1.0group [15 (20) mm Hg] (P!0.032); however, SAP did notexceed baseline values in either group (Fig. 2). HR increasedafter induction of anaesthesia in the R0.5 group andremained unaltered in the R1.0 group. In response totracheal intubation, HR similarly increased in both groups[6 (8) and 6 (14) beats min21 in the R0.5 and R1.0 groups,respectively] (Fig. 2).

Maternal plasma concentrations of catecholamines areshown in Table 2. Baseline norepinephrine and epinephrineconcentrations did not differ between the groups. Norepi-nephrine concentrations remained unchanged by intubation

Assessed for eligibility(n=55)

Randomization: 48

Excluded (n=7) Patients not eligible (n=1) Refused to participate (n=4) Other reasons (n=2)

Group R0.5 (n=24)

Analysed (n=24)Excluded from analysis(n=0)

Group R1.0 (n=24)

Analysed (n=24)Excluded from analysis(n=0)

Fig 1 CONSORT flow chart showing the flow of subjects throughthe trial.

Table 1 Maternal characteristics. Values are mean (range), mean(SD), or number (%). There were no significant differences betweenthe groups

R1.0 (n524) R0.5 (n524)

Age (yr) 32 (25–41) 32 (24–41)

Weight (kg) 74 (9) 78 (17)

Height (cm) 160 (4) 160 (4)

Gestational age (weeks) 34.6 (3.3) 34.2 (3.1)

MgSO4 therapy (%) 24 (100) 24 (100)

Hydralazine (%) 9 (38) 7 (29)

Estimated blood loss (ml) 786 (294) 804 (301)

Induction-to-delivery interval(min)

10.7 (1.7) 9.8 (2.2)

Uterine incision-to-deliveryinterval (s)

115 (61) 106 (42)

–2 0

40

80

120

SA

P (

mm

Hg)

160

200

240

–1

R

R0.5 (n=24)R1.0 (n=24)

0 1 2 3 4 5 6 7

–2 40

60

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(be

ats

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–1)

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0 1 2 3 Time after intubation (min)

4 5 6 7

* * * *

* * * *

* * * *

*

* * * * * *

*

* * *

*

† †

Fig 2 SAP and HR in the R0.5 and R1.0 groups measured beforeinjection of the study drug [remifentanil (R), t! –2 min], justbefore intubation (t!0), maximum response within 1 min afterintubation, and every 1 min for 7 min after intubation. Valuesare mean (SD). *P,0.05 vs baseline (t!–2 min); †P,0.05 vs theR1.0 group.

BJA Park et al.

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Secondly, given the heterogeneity of surgical models, arandom effects model may, indeed, have made more sensefrom a clinical perspective. However, it could equally beargued that the pain model was the only differencebetween studies, with all other aspects being clinicallyhomogenous: we included clinical trials of high reportingquality that studied patients with similar levels of initialpain intensity and used consistent methods of measuringpain over the same time periods. Additionally, while notstated in the text, we performed a sensitivity analysis usinga random effects model. None of the estimates for theprimary outcome changed in direction, statistically signifi-cant analyses remained as such, and changes in effect sizewere minimal. However, 95% confidence intervals were, pre-dictably, generally wider. For example, the combined NNTs(95% confidence intervals) for at least 50% pain relief at 4h were 3.7 (2.6–6.7) when applying a random effectsmodel as opposed to 4.0 (3.4–5.0) when our originalmethod of analysis was applied. Finally, we agree that dupli-cating the number of patients in a placebo group betweentwo comparisons may generate a unit-of-analysis error. AsSahgal and colleagues point out, there are several methodsof addressing this. We chose the simplest method—splittingthe shared group—and, as with our other sensitivity ana-lyses, found clinically insignificant differences in point esti-mates and variances and no difference in statisticalsignificance. For example, the combined NNTs for at least50% pain relief at 4 h were 4.3 (3.6–5.3) when splitting theshared group as opposed to 4.0 (3.4–5.0) when the patientswere duplicated. We hope that this additional informationadequately addresses their concerns and further contributesto the understanding of a complex systematic analysis of theliterature such as ours.

Conflict of interestE.M. has consulted for Javelin Pharmaceuticals, Wyeth, andOrtho-McNeil-Janssen Pharmaceuticals. M.S.C. is an employeeof Johnson & Johnson Pharmaceutical Research & Develop-ment. Johnson & Johnson Pharmaceutical Research &Development is an affiliate of Ortho-McNeil-Janssen Pharma-ceuticals, Inc., which markets several analgesic drug productsincluding opioids and over-the-counter analgesics such asacetaminophen. She participated in the design of the study,before she joined Johnson & Johnson PharmaceuticalResearch & Development.

E. McNicol1*A. Tzortzopoulou2

M. S. Cepeda1

M. B. D. Francia3

T. Farhat1

R. Schumann1

1Boston, USA2Elefsina, Greece3Manila, Philippines*E-mail: [email protected]

1 McNicol ED, Tzortzopoulou A, Cepeda MS, Francia MBD, Farhat T,Schumann R. Single-dose intravenous paracetamol or propaceta-mol for prevention or treatment of postoperative pain: asystematic review and meta-analysis. Br J Anaesth 2011; 106:764–75

2 Barden J, Edwards JE, McQuay HJ, Moore RA. Pain and analgesicresponse after third molar extraction and other postsurgicalpain. Pain 2004; 107: 86–90

doi:10.1093/bja/aer283

Consent of subjects for general anaestheticin Caesarean sectionEditor—We read with interest the paper by Park and col-leagues1 regarding attenuation of the cardiovascularresponse to tracheal intubation using a bolus dose of remi-fentanil. While we commend the authors for trying to findpharmacological answers to a difficult clinical question, wefelt that it remained unclear quite how patients wereselected for this study and we would question the necessityof all these women undergoing general anaesthesia (GA) forCaesarean section. The authors state that ‘a total of 48women with severe PET undergoing elective or urgent Cae-sarean delivery under GA were enrolled’. They then went onto discuss lower segment Caesarean section (LSCS) underregional anaesthesia and state that women were consentedfor GA. There is no mention of counselling women as to thepossible benefits and risks of regional anaesthesia balancedwith those of a general anaesthetic. It worried us on readingthis paper that it was not made clear whether womenenrolled in this study had been given full disclosure of theanaesthetic options available to them. In this day and age,it is widely acknowledged that, where possible, regionalanaesthesia is the preferred mode unless there are specificcontraindications (e.g. severe PET with coagulopathy,maternal refusal, urgency of the situation). One of the great-est risks of all being the very thing they were studying,namely surges in arterial pressure that can result in disas-trous consequences coupled with the possible risk of airwaycomplications. They have also justified their use of GA forLSCS in some of the study group as indicated by fetal distress.However, we would argue that if Caesarean section neededto be expedited then it is likely a spinal anaesthetic wouldhave been a minor delay in comparison with the rest of theset-up required for such a study to take place. It may wellbe that all of the study group had a coagulopathy sosevere that regional anaesthesia was contraindicated orthat each of the women made an informed decision torefuse regional anaesthesia and if this is the case, it wouldhave been preferable if it had been clearly stated in the pub-lication. To omit such details is potentially misleading. Wewrite seeking clarification on this issue as we feel it is animportant aspect of such a study.

Conflict of interestNone declared.

Correspondence BJA

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W. Birts*A. CombeerEpsom, UK*E-mail: [email protected]

1 Park BY, Jeong CW, Jang EA, et al. Dose-related attenuation of car-diovascular responses to tracheal intubation by intravenous remi-fentanil bolus in severe pre-eclamptic patients undergoingCaesarean delivery. Br J Anaesth 2011; 106: 82–7


Reply from the authorsEditor—We thank Drs Birts and Combeer for their constructivecomments on the use of and consent for general anaesthesiafor Caesarean delivery in patients with pre-eclampsia in ourstudy.1 In particular, they are concerned about a transientbut severe hypertension along with cerebral haemorrhageand cardiac failure after tracheal intubation,2 and risk ofairway complications. We understand, in most Westerncountries, neuraxial anaesthesia is the standard for electiveCaesarean delivery and has become a preferred techniqueto provide labour analgesia or anaesthesia for Caesareandelivery even among women with severe pre-eclampsia.3 4

However, there are many differences in ethical and culturalvalues in different countries. We had 2257 cases of Caesareandelivery during the last 5 yr (2006–10). There were 814(36.1%) elective sections, of which 718 (88.2%) had generaland 96 (11.8%) had spinal or epidural anaesthesia. On theother hand, we had 1443 (63.9%) emergency Caesareandeliveries, 1371 (95.0%) of which were done under generalanaesthesia and only 72 (5.0%) under spinal or epiduralanaesthesia. For East Asians, airway problems (e.g. difficultintubation or ventilation) are not a major problem and thusmajor issue in determining the anaesthetic technique for Cae-sarean delivery. Moreover, we feel that the incidence of aspira-tion pneumonia during general anaesthesia for Caesareandelivery is lower compared with Western countries. In fact,neuraxial anaesthesia is not considered safer than generalanaesthesia for elective Caesarean delivery in our country.There is no set standard of care for elective Caesarean deliv-ery, although general anaesthesia using volatile anaestheticin 50% N2O is still the most popular anaesthetic techniquein most institutions. Nevertheless, the potential risks andbenefits of general, spinal, or epidural anaesthesia wereexplained to patients, who accepted the anaesthetist’s incli-nation towards general anaesthesia and gave their writteninformed consent to participate in our study. As far as exag-gerated pressor response to laryngoscopy and tracheal intu-bation is concerned, we feel that general anaesthesia withthe aid of ultra-short-acting remifentanil described in ourarticle1 would be acceptable, if not ideal, for gestationalhypertensive women. To date, we have not encountered anydisastrous consequences due to pressor response andairway problems during Caesarean delivery. While there is apreference for regional anaesthesia for Caesarean delivery incurrent anaesthetic practice in Western countries, we believe

that whether the regional anaesthesia has advantages forboth the mother and baby over general anaesthesia has yetto be determined in East Asia.

Conflict of interestNone declared.

K. Y. Yoo*B. Y. ParkJ. U. LeeGwangju, Republic of Korea*E-mail: [email protected]

1 Park BY, Jeong CW, Jang EA, et al. Dose-related attenuation of car-diovascular responses to tracheal intubation by intravenous remi-fentanil bolus in severe pre-eclamptic patients undergoingCaesarean delivery. Br J Anaesth 2011; 106: 82–7

2 Lawes EG, Downing JW, Duncan PW, Bland B, Lavies N, Gane GA.Fentanyl–droperidol supplementation of rapid sequence inductionin the presence of severe pregnancy induced and pregnancy-aggravated hypertension. Br J Anaesth 1987; 59: 1381–9

3 Cooper GM, McClure JH. Maternal deaths from anaesthesia. Anextract from Why Mothers Die 2000–2002, the Confidential Enqui-ries into Maternal Deaths in the United Kingdom: Chapter 9:Anaesthesia. Br J Anaesth 2005; 94: 417–23

4 Dyer RA, Piercy JL, Reed AR. The role of the anaesthetist in themanagement of the pre-eclamptic patient. Curr Opin Anaesthesiol2007; 20: 168–74


Tracheal intubation with the direct andindirect laryngoscopes in patients withcervical spine immobilizationEditor—In a randomized, controlled clinical study in patientswith cervical spine immobilization, McElwain and Laffey1

demonstrated that intubation performance of the Airtraq laryn-goscope produced a reduction in the Intubation Difficulty Scale(IDS) score, improvement in the Cormack and Lehane glotticview, and decrease in the need for optimization manoeuvres,compared with both the Macintosh and C-MAC laryngoscopes.In addition to the limitations described in the discussion, thereare additional issues affecting the conclusions of this study.

First, a significantly better laryngeal view was obtainedwith the Airtraq laryngoscope compared with the Macintoshand C-MAC laryngoscopes. However, the authors did notprovide the blade sizes of the Macintosh and C-MAC laryngo-scopes used in this study. We would like to know whether asingle size blade was used for all patients in the Macintoshor C-MAC group. The C-MAC laryngoscope has two Macintoshblades (sizes 3 and 4) available for the adult patients. Theshapes, lengths, and angulations of the two blades aresomewhat different.2 Because of the lower angulation ofthe size 3 blade, it is preferred for daily practice. The size 4blade is more curved, resulting in a higher angulation witha wider view of the glottis, which may be advantageous if

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EDITORIAL I

Saving Mothers’ Lives: the 2006–8 anaesthesia perspectiveC. A. WongDepartment of Anesthesiology, Northwestern University Feinberg School of Medicine, 251 E. Huron St., F5-704, Chicago, IL, USA

E-mail: [email protected]

A single death is a tragedy; a million deaths is a statistic (KurtTucholsky: Franzosischer Witz, 1932).

The individual stories of maternal death, documented in Con-fidential Enquiries into Maternal Deaths, are tragic and com-pelling, and have informed many recommendations in thepast half-century that have improved maternal and neonataloutcomes in the UK and probably, around the world. The indi-vidual stories continue with the recent publication of theEighth Report of the Confidential Enquiries into MaternalDeaths in the UK, ‘Saving Mothers’ Lives: Reviewing MaternalDeaths to Make Motherhood Safer—2006–08’ (hereafterreferred to as the Report).1 In this month’s issue of theBritish Journal of Anaesthesia, Drs McClure, Cooper, andClutton-Brock, on behalf of the Centre for Maternal andChild Enquiries, have summarized the findings of the EighthReport.2 In the past, the chapters summarizing deaths attrib-uted directly to anaesthesia and critical care were repub-lished in the British Journal of Anaesthesia, but due tocopyright issues, the authors have written a review of thecurrent Report.2

Between 2006 and 2008, 261 maternal deaths werereported; 331 existing children and 147 live-born new-borns lost their mothers.1 The good news is that theoverall maternal risk ratio (MMR) decreased comparedwith the 2003–5 report. Since 1985, there is a significantdownward trend in the MMR due to direct causes (deathsresulting from obstetric complications). The decreasefrom the previous triennium is primarily due to adecrease in deaths from pulmonary embolus, and to alesser extent, obstetric haemorrhage. In all likelihood,this decrease is attributable to the development of proto-cols to prevent embolism and treat haemorrhage that

were developed and implemented after previous reports.A worrying change is the increase in deaths fromgenital tract infection.

According to the latest World Health Organization (WHO)data, the MMR has decreased worldwide by 34% since1990.3 Still, an estimated 358 000 women died ofpregnancy-related disease in 2008. This rate equates tomore than 1000 deaths per day or 42 deaths per hour. Thevast majority of these deaths occur in developing countries.The WHO 2000 Millennium Development Goal Five (MDG5)is to reduce MMR by 75% between 1990 and 2015. Unfortu-nately, at the current rate of decline (2.5% per year), we aremaking insufficient progress towards this goal.3 In fact, theMMR is increasing in some countries, including the USA.3

Better data collection may explain some, but not all of thisincrease.4

Despite the improved MMR observed in the UK, there is noroom for complacency. The MMR trend for indirect deaths(deaths resulting from pre-existing disease, or disease thatdeveloped during or was aggravated by pregnancy) isincreasing. Of equal concern is the number of cases inwhich substandard care was judged to be present. Fordirect deaths, the proportion has hovered between 60%and 70% for the past decade.1 For the first time, the pro-portion of indirect deaths in which care was substandardwas .50%.

The UK is not alone in this regard. The French NationalExpert Committee on Maternal Mortality (CNEMM) recentlypublished a report summarizing maternal mortality inFrance from 2001 to 2006, using techniques similar tothe Confidential Enquiries.5 Almost half (46%) of deathswere judged avoidable. In the Netherlands between 1993

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The women who diedIn this triennium, two women died from failure to ventilatethe lungs, four from postoperative complications and onefrom leucoencephalitis. Two of the seven women were obese.

Failure to ventilate the lungsThere were two deaths as a result of a failure to ventilate thelungs, one after induction of general anaesthesia and onewhen a tracheostomy tube came out in a critical-care ward.

In the first woman, the anaesthetist failed to stop trying tointubate the trachea even though oxygenation was achievedthrough an intubating laryngeal mask airway (ILMA).Failed intubation guidelines1 were followed, to an extent, inthis very stressful situation, but oesophageal intubationthrough the ILMA was not recognised and further hypoxiaoccurred. The woman was coughing but was not allowed towake up, and a second dose of thiopental and a long-actingneuromuscular-blocking drug were given even though theend-expiratory CO2 monitor indicated that the woman’slungs were not being ventilated. Cricothyrotomy was notattempted.

Patients do not die from a ‘failure to intubate’. They dieeither from failure to stop trying to intubate or from undiag-nosed oesophageal intubation.

Bruce Scott 19862

Much of the success that these Confidential Enquiries intoMaternal Deaths have had in reducing Direct deaths fromanaesthesia has been from tackling airway-related deaths.In the 1967–69 triennial report for England and Wales3

there were 32 such deaths. Striving for absence of suchdeaths is achievable, as in 1994–96, but requires continualefforts. Management of failed intubation/ventilation is acore anaesthetic skill that should be rehearsed and assessedregularly.4 The infrequent use of general anaesthesia inobstetrics, and hence the lack of experience, makes thisextremely important.5 In one region of the UK, during a5-year period from 1999 to 2003, there was an incidence offailed tracheal intubation of one in 238 general anaethetics.In half of these women, there was a failure to follow anaccepted protocol for failed tracheal intubation.6 Recentsurveillance of failed tracheal intubation for obstetric gen-eral anaesthesia conducted through the United KingdomObstetric Surveillance System (UKOSS which is discussedin detail in the Introductory Chapter of this Report)between April 2008 and January 2010 identified 51 womenin an estimated 1.4 million maternities, giving an estimatedrate of failed intubation of 36 cases per million maternities(95% CI 27–48 per million maternities [personal commu-nication with UKOSS]).

Human errors and failures in clinical practice are inevita-ble. Strategies and guidelines need to be in place when errorsor failures occur.7 Assessment of nontechnical skills, such assituation awareness, is given high priority in the aviationindustry but is also very important in medical practice. Inanaesthesia, one must always consider the worst-case sce-nario, implement drills and be aware of what may happenunder stress. An anaesthetist may perceive failed intubationas failed performance, which creates pressure to persist.There is the added fear of acid aspiration, but the impor-tance of maternal oxygenation cannot be overemphasised.

In managing a rare critical situation, it is important to beprepared to implement an accepted drill fully and to main-tain priorities. Drills should not be complex and must bepracticed regularly. The anaesthetist must avoid blind alleysand the natural behaviour patterns of fixation and denial.

It is also pertinent to note that the woman discussedabove had a working epidural in labour when it was decidedto perform a Category 2 caesarean section. Subsequentlythere was a sustained fetal bradycardia, which escalated theurgency of caesarean section to Category 1. The epiduralhad not been topped up to provide surgical anaesthesia forcaesarean section because the anaesthetist planned to topthe epidural up in theatre. If the epidural had been toppedup when it was decided she was to have a caesarean section,general anaesthesia may not have been required.

Epidural anaesthesia for operativedelivery: learning points

Epidural analgesia that has been working well in labourshould be topped up to provide full surgical anaesthesiawithout delay once the decision for operational deliveryhas been made. If the woman cannot be immediatelytransferred to an operating theatre and full epiduralanaesthesia is established on the labour ward, the anaes-thetist and full resuscitation equipment should be imme-diately available and full ‘epidural monitoring’ provided.

A second woman died in a critical-care unit from loss ofthe airway when her tracheostomy tube came out whilebeing turned. She had a known airway problem and knowndifficulty with her tracheostomy.

A clear strategy of management for this scenario wasrequired in advance, including the use of small trachealtubes and quick referral for senior help out of hours.Autopsy revealed a very small larynx and lobular brown tis-sue obscured the tracheostomy orifice.

In these two cases, non-consultant anaesthetists wereexposed to rare emergencies without immediate seniorbackup. Inexperience of rare situations is difficult to

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