MCQ March 2010

1. MC157 [Mar10] New Q An 18 yo with Fontan Circulation undergoing exploratory laparotomy. On ICU vent, sats 70%. Which ventilator parameter would you INCREASE to improve his sats?A. Bilevel pressureB. Expiratory timeC. Inspiratory timeD. Peak inspiratory pressureE. PEEP

2.A 7 kg Infant with tetralogy of fallot, post BT-shunt. Definitive repair at later date. Paralysed and ventilated. sats 85% baseline, now 70%, best treatment:A. Increase FiO2 from 50 - 100% - ↓HPV → ↓PVR → ↑B-T shunt QB. Esmolol 70 mcgC. Phenylephrine 35 mcg (vasopressors are relatively ineffective in children - systemic pressures are determined by CO (HR x SV) and filling ALSO this is a massive dose)D. Morphine 1 mgE. 1/2 NS with 2.5% dex 70 mls

A. FiO2 to 100% this is a real answer and will also improve HPV and increase B-T shunt QB. Beta blocker may help slow heart rate and increase diastolic filling and preload, and MAY

help to increase diameter of RVOT. C. Phenylephrine will increase SVR and therefore left-sided pressures, thereby reducing right-to-

left shunt. BEST ANSWER D. Morphine will probably make little difference to a patient who is paralysed and ventilated, E. Crystalloid will increase preload if a big enough bolus is given, and this may dilate RVOT and

decrease right-to-left shunt.

Giving 100% oxygen may reduce hypoxic pulmonary vasoconstriction, pulmonary vascular resistance and allow more blood to flow through the Blalock-Taussig aortopulmonary shunt where it can be oxygenated. Other PVR lowering strategies include

sodium bicarbonate 1-2 mmol/kg low inspiratory pressure ventilation with long expiratory times (although I suspect this may

produce hypercapnoea) general anaesthesia Phenylephrine 35 mcg is quite a high dose in a 7kg infant (I have read here 0.5 - 2 mcg/kg)

but is one of the methods cited to increase SVR along with knee-chest positioning abdominal pressure on the aorta Finally RV filling with reduction in RVOT obstruction can be facilitated by B-blockers which

slow HR, likewise opioids (although morphine 1 mg to 7 kg child is excessive), general anaesthetics (particularly the inhaled ones) and fluid loading. Given that the question was remembered with doses, I wonder if the key to the question lies there rather than the choice of drug.

3. MN41 Von Hippel-Lindau disease is associated with: A. increased risk of malignant hyperthermiaB. meningiomasC. peripheral neuropathyD. pheochromocytomasE. poor dentition

D - Von Hippel–Lindau disease (VHL) is a rare, autosomal dominant genetic condition[1]:555 in which hemangioblastomas are found in the cerebellum, spinal cord, kidney and retina. These are associated with several pathologies including renal angioma, renal cell carcinoma and phaeochromocytoma. VHL results from a mutation in the von Hippel–Lindau tumor suppressor gene on chromosome 3p25.3 Wikipedia - Disco 28/6/10

4.70 year old post TKJR. On sub-cut heparin. Develops clinical DVT and platelets 40 (sounds like HITS type-II). ManagementA. EnoxaparinB. Fondoparinux - looks promising but at this stage awaiting larger, multi-centre RCTs to demonstrate efficacyC. Heparin by infusionD. Lepirudin - recombinant anticoagulant from leaches - direct IIa inhibitor; monitored with APTT (best answer at this stage); dose 0.08mg/kg/hr no load + titrate to APTTE. Warfarin - can cause procoagulant state and gangrene

Management of HIT: First task is to discontinue unfractionated heparin from ALL sources (including heparin-coated lines, etc). LMWH can also cause HIT, therefore not suitable as a replacement. Fondaparinux is an indirect Factor-Xa inhibitor (synthetic pentasaccharide), and there are some reports of it being used in HIT successfully. Warfarin (Vit K antagonist) is contraindicated in acute HIT (or if suspected HIT), as it can cause skin necrosis or venous limb gangrene. Current recommendations are to treat with DTI's (lepirudin, argatroban, bivalirudin) or danaparoid. Although danaparoid is a LMW heparinoid, there is an extremely low cross-reactivity rate with HIT antibodies, and this is rarely clinically significant. As danaparoid is not an option, the best answer is therefore a direct thrombin inhibitor (DTI), and lepirudin is the only one listed, so answer is D. References: Greinacher A. Heparin-induced thrombocytopenia, J Thromb Haemost 2009;7(Suppl. 1):9-12. Shantsila, et.al. Heparin-Induced Thrombocytopenia: A Contemporary Clinical Approach to Diagnosis and Management, Chest 2009; 135:1651-1664. Therapeutic Guidelines - Cardiovascular (electronic version), 2008.

5.HypercalcaemiaA. Chovostek's signB.C.D.E. Short QT

6.Drug eluting stent 6 months old. On aspirin and prasugrel 10mg. Elective lap chole for biliary colic.A. Do case while taking both.B. Do case while stopping both.C. Stop Prasugrel for 7 days, keep taking aspirin.D. Stop Prasugrel for some other different timeE. Post-pone for 6 monthsI had never heard of prasugrel until I read this question, but it is the same class of drug as clopidogrel (not surprising given the context). As per AHA/ACC Guidelines, recommended to continue dual anti-platelet therapy for 365 days, and I would consider prasugrel the same as clopidogrel. Given that this is an elective procedure, and the potential for blood loss (while usually minimal) is significant (especially given dual anti-platelet therapy), the procedure should be delayed for another 6 months

(i.e. 12 months from time of stent placement. The risk of an in-stent thrombosis is high if both anti-platelet drugs are not continued for the full 12 months.

7.Person newly diagnosed as MH susceptible. Which is untrue?A. ?B. can have had an uneventful 'triggering' anaestheticC. Recommended to use an anaesthetic machine which has not had volatiles through itD. ?E. there have been case reports of MH occurring up to 48 h post op

B is TRUE - may have had an uneventful trigger-type anaesthetic previously. (Oxford Handbook of Anaesthesia, 2nd Ed, p. 260) C is not strictly true (depending how you interpret the question). If a machine that has never had volatiles through it is available then that's great, but in practice you need to remove the vaporisers, change the circuit and CO2 absorber, and flush with high fresh gas flows for 20-30 minutes. (Oxford Handbook of Anaesthesia, 2nd Ed, p. 263) E is TRUE also. Oxford Handbook states that rarely it can develop 2-3 days post-op and manifest as massive myoglobinuria +/- renal failure secondary to rhabdomyolysis. (Oxford Handbook of Anaesthesia, 2nd Ed, p. 260)

8. MZ80 ABG pH 7.12, PO2 100, PCO2 65, HCO3 20.3, BE -10. Consistent with?A. Chronic renal failureB. Malignant hyperthermiaC. Diabetic ketoacidosisD. End-stage respiratory failureE. Ethylene glycol toxicity

A. FALSE - CRF will give a metabolic acidosis with compensatory respiratory alkalosisB. TRUE - MH will give metabolic lactic acidosis and elevated PCO2 (mixed acidosis)C. FALSE D. FALSEE. FALSE - Ethylene Glycol acutely causes a high AG metabolic acidosis with hyperventilation

Kussmaul breathing

9.Cocaine overdose. What is false? (rpt Q)A. EuphoriaB. ?C. ?D. ?E. Miosis (causes mydriasis or dilated pupils)

10.Maximum dose (with low risk of toxicity) of lignocaine (with adrenaline 1:100000) for liposuction with tumescence techniqueA. 3 mg/kgB. 7 mg/kgC. 15 mg/kgD. 25 mg/kg E. 35 mg/kg

Apparently up to 35-55 mg/kg of lignocaine has been "safely" used in this technique, although you would have to have a low threshold for suspecting toxicity.

11.Compared to lignocaine, bupivacaine isA. Twice as potentB. Three times as potent C. Four times as potentD. Five times as potent E. Same potencyIf procaine =1, then lignocaine potency=2, and bupivacaine potency =8. Therefore bupivacaine is 4 times as potent as lignocaine (Foundations of Anesthesia: Basic Sciences for Clinical Practice by Hemmings & Hopkins, 2nd edn, p.394) Other recommended texts (Primary exam pharm texts) give differing values compared to procaine, but all give a ratio of 4x potency for buipvacaine:lignocaine (Stoelting and Katzung)

12.cerebral aneurysm sugery. Propofol / remifentanil / NMDR. DOA monitoring (Entropy). MAP 70 , HR 70/min, State entropy 50, Response entropy 70. What do you do?A. B. MetaraminolC. Check TOFD. NothingE. Increase TCI

A.B. MAP OK - there is no reason to be chasing ICPs or anything at this stageC. TRUE - response entropy of 70 suggests the patient may not be adequately paralysed, so

check TOFD. maybeE. whilst entropy is up slightly I would wait for the trend and with a MAP of 70 and a CPP of ?55

I would not increase the propofol

13.Paralysed with atracurium. TOF is 1(25%). You give a dose of 0.1 mg/kg mivacurium to close the abdomen. When will you be back to TOF 1(25%)?A. 5 minB. 10 minC. 30 minD. 60 minE. 90 minA study by Naguib et. al. showed that after an initial intubating dose of atracurium, and spontaneous recovery of the first twitch (T1) to 10% of its control height, a maintenance dose of 0.1mg/kg of mivacurium resulted in a time of 25 minutes to regain T1=10%. My guess would be the answer is C, but it's still a guess Reference: Naguib, et al. Interactions between Mivacurium and Atracurium. BJA 1994; 73:484-89

14.Plenum VaporiserA.? something with fresh gas flows B. Relies on a constant flow of pressurised gas C. Out of circle D. Not temperature compensated E. volatile injected into fresh gas slow?

A - ? B - TRUE. Upstream gas source required to push fresh gas through the vaporizer (opposite to Draw-over vaporizer) C - ? FALSE. Don't exactly understand the question/stem. You can use a plenum vaporizer with OR without a circle (e.g. T-piece in paeds)

D - FALSE. Most ARE temperature compensated E - FALSE. Not necessarily, although some can. Not true exclusively.

15.Interscalene block, patient hiccups...where do you redirect your needle?A. Anterior B. Posterior C. Caudal D. Cranial E. Superficial

Answer is B (see Oxford handbook of Anaesthesia, 2nd Edn, p. 1077). Phrenic nerve stimulation occurs if you are too anterior.

16.What is the SVR in a patient with MAP 100mmHg, CVP 5, PCWP 15, CO 5L/min?A. ?0.8 B. ?3 C. 520D. 1280 E. 1520 dynes.sec/cm-5

SVR = (Systemic A-V Pressure difference) / Flow Therefore SVR = (100-5)/5 = 95/5 = 19 mmHg/L/min To convert to dynes.sec/cm-5 then multiply by 80; this gives us 1520 dynes.sec/cm-5. Therefore ANSWER is E.

17.Accidentally cannulate carotid artery with 5 lumen 7 Fr CVC preop for a semi urgent CABG. Most appropriate next response is toA. Get vascular surgeon to repair it and continue with surgery and heparin B. Leave it in. Do CABG. Pull it out post op. C. Pull it out, compress. Delay surgery for 24hrs D. Pull it out compress. Continue with surgery + heparin. E. Pull it out. Compress. Continue with surgery no heparin.

18.Stellate ganglion (Repeat Question)A. Anterior to scalenius anterior B. ? C. ? D. ? E. ?

The stellate ganglion lies ANTERIOR to the scalenius anterior muscle ("Anaesthesia UK" website - Stellate Ganglion Block - http://www.frca.co.uk/article.aspx?articleid=100538)

19.The median nerve (REPEAT)A. can be blocked at the elbow immediately medial to the brachial arteryB. can be blocked at the wrist between palmaris longus and flexor carpi ulnarisC. can be blocked at the wrist medial to flexor carpi ulnarisD. is formed from the lateral, medial, and posterior cords of the brachial plexusE. provides sensation to the ulna half of the palm

A. TRUEB. FALSE - between palmaris longus and flexor carpi radialis

C. FALSE - lateral to flexor carpi ulnarusD. FALSE - The median nerve is formed by a lateral and medial head (from the lateral and

medial cords respectively) and has no contribution from the posterior cord. It runs down the upper arm initally lateral to the brachial artery, but changes to be medial to the artery about halfway down the arm, and is therefore MEDIAL to the brachial artery at the elbow

E. FALSE - sensation to the lateral 3 and a half fingers and corresponding lateral area of palm - radial side

20.Patient for total knee replacement under spinal anaesthetic. Continous femoral nerve catheter put in for post op pain relief. Good analgesia and range of motion 18hrs post op. 24hrs post op, patchy decreased sensation in leg and unable flex knee. What is the cause?A. Compression neurapraxia (i think it said due to torniquet)B. DVT C. Muscle ischaemia (muscle is good for 4hrs of warm ischaemic time)D. Damage to femoral nerve - femoral nerve does not flex kneeE. Spinal cord damage - unilateral and no neuraxial intervention makes this unlikelyInability to flex the knee is not a femoral nerve problem - it is sciatic. This problem seems to have

21.A 75yo male with moderate aortic stenosis (valve area 1.1cm2).. Gets mild dyspnoea on exertion but otherwise asymptomatic. needs hip replacement.A. Continue with surgery B. Beta block then continue C. Get myocardial perfusion scan D. Postpone surgery awaiting AVR E. Postpone surgery awaiting balloon valvotomy

Median life expectancy5 - syncope3 - angina2 - dyspnoea

According to ACC/AHA Guidelines on Perioperative Cardiovascular Evaluation and Care for Noncardiac Surgery (2009 version with B-blocker update), my answer would be D=TRUE. We are told the man has moderate AS, and his valve area of 1.1 cm2 confirms that. We are told he gets mild dyspnoea on exertion but is otherwise asymptomatic. However, the fact that he does get SOB means he has symptomatic aortic stenosis. Unable to say how many METS he can do from the short history. The guidelines recommend that "if the aortic stenosis is symptomatic, elective noncardiac surgery should generally be postponed or cancelled. Such patients require aortic valve replacement before elective but necessary noncardiac surgery" (see p. e184, Section 3.5 Valvular Heart Disease). It is a bit unclear if this section just refers to severe aortic stenosis, although one could make that argument. However, logically a patient with moderate symptomatic AS at age 75 may well be a candidate for a valve replacement anyway, purely from the cardiac point of view. The natural history is that average progression of moderate AS is a decrease in valve area of 0.1 cm2 per year, and once symptoms occur average survival is 2-3 years. Also, the table that defines "active cardiac conditions" shows that severe aortic stenosis is defined as mean P gradient > 40mmHg OR valve area < 1.0 cm2 OR symptomatic. You could therefore argue that symptomatic AS is an "active cardiac condition" and should be evaluated first.

22.similar to above, patient for fempop bypass (i believe it said "angioplasty"), history of CCF. Also has diabetes on oral hypoglycaemics, controlled hypertension and atrial fibrillation at rate of 80bpm . A. Medium risk surgery, medium risk patient B. Medium risk surgery, high risk patient

C. High risk surgery low risk patient D. High risk surgery, medium risk patient E. High risk surgery, high risk patient.

Fem-pop bypass is HIGH risk surgery (although an angioplasty would not be if done under LA +/- sedation).

stratifying patient risk ACC/AHA Guidelines: 1. "active cardiac conditions" that when present indicate major clinical risk

Unstable coronary syndromes o Unstable or severe angina (CCS class III or IV) o Recent MI

Decompensated HF o NYHA class IV o Worsening or new-onset HF

Significant arrhythmias o High-grade A-V block o Mobitz type II A-V block o 3rd degree A-V block o Symptomatic ventricular arrhythmias o SVT (incl AF) with uncontrolled ventricular rate (HR>100bpm @ rest) o Symptomatic bradycardia o Newly recognised VT

Severe valvular disease o Severe AS (mean P gradient > 40mmHg; valve area < 1.0cm2; symptomatic)

OR symptomatic AS regardless of the gradeo Symptomatic mitral stenosis (progressive SOBOE, exertional presyncope, or

HF)2. Intermediate risk denoted by the presence of "clinical risk factors"

ischaemic heart disease compensated or prior heart failure diabetes mellitus renal insufficiency (creatinine >2mg/dL, which is >177umol/L) cerebrovascular disease

3. minor predictors Age >70 Abnormal ECG (LVH; LBBB; ST-T abnormalities) Rhythm other than sinus Uncontrolled systemic hypertension

RH35 (NEW)23.Best Approach for a Sub-Tenon's block?A. inferonasal b. inferotemporal c. medial canthus d. superior nasal e. superior temporal

24.Baby with TracheoOesophageal Fistula found by bubbling saliva and nasogastric tube coiling on xray. Best immediate management?A. Bag and mask ventilate B. Intubate and ventilate

C. position head up, insert suction catheter in oesophagus (or to stomach?)D. Place prone, head down to allow contents to drain E. Insert gastrostomy

A - FALSE. Not unless the baby is in respiratory distress and/or hypoxic. May inflate stomach by ventilating through fistula. B - FALSE. Just because the baby has been diagnosed with TOF is not an immediate indication for intubation in and of itself. C - TRUE. Neonates with TOF should have a "nasogastric" tube inserted into the oesophageal stump to drain secretions and prevent accumulation in the blind-end pouch. The NGT should be connected to continuous suction. The infant should be nursed prone or in the lateral position with 30 degrees head up tilt to decrease the risk of aspiration. See A Practice of Anesthesia for Infants and Children - 4th edition by Cote, Lerman, Todres; p.755. Saunders (2009) D - FALSE. Can nurse prone, but lateral with head up tilt seems to be the recommended and most commonly cited method. E - FALSE. Initial management as above (see C - TRUE), and then repair. Gastrostomy may be performed, but not best immediate management.

25.60yo Man with anterior mediastinal mass, during induction for mediastinoscopy....lose cardiac output, decreased saturations, drop in ETCO2. ManagementA. Adrenaline B. CPR C. CPB D. Place prone

I don't know if this was a bit of a trick question but setting aside the complexities and potential side-effects/complications of mediastinal masses, the answer may be that in the event of cardiac arrest you must perform CPR. If CPB has been organised pre-op and/or is available then that's great, but the first response would be to attempt to resuscitate the patient with CPR and look for/treat reversible causes. Answer=B. However - significant compression of vascular structures (including the heart) can occur secondary to large mediastinal masses, and changing patient position may improve things. Perhaps the answer should be to turn prone and see if there is improvement? Any ideas?

Reference: Curr Opin Anesthesiology 2007 20:1-3

Options are reposition (lateral or prone) vs emergency sternotomy and decompression great vessels.

26.Post thyroidectomy patient, patient in PACU for 30 minutes. Develops respiratory distress. Most likely cause?A. Hypercalcemia from taking parathyroids - causes hypocalcaemiaB. Bilateral laryngeal nerve palsies - chronicity wrongC. bleeding and haematoma D. Tracheomalacia - chronicity wrong, will have obstruction immediately after extubationE.

27.Best way to prevent hypothermia in patient undergoing a general anaesthetic (Repeat question)A. Prewarming of patient B. C.D. Warm IV fluids

28.Main indication for biventricular pacing isA. complete heart block B. congestive cardiac failure c. VF D.

According to Yao & Artusio (6th edn, p.236-7), biventricular pacing is defined as a lead in the RV to pace the interventricular septum, and a lead in the coronary sinus which can pace the LV lateral free wall. This is apparently most commonly used in patients with LBBB which can cause dyssynchronous contraction of the LV leading to impaired systolic function. The biventricular pacing "resynchronises" LV contraction and improves systolic function. They quote indications as:

(i) severe cardiomyopathy (EF<35%), (ii) LBBB with NYHA class III or IV symptoms despite maximal medical therapy.

29.Desflurane TEC6 vaporiser, unable to turn dial on. This is NOT becauseA. vapouriser is tilted B. Hotter than 39C C. On battery power D. Interlock not engaged, or not seated properly (or something like that) E. other vapouriser is already on

30.Desflurane vaporiser, heated because ofA. High SVP B. High boiling poing C. Low SVP D. High MAC E. Low MAC

31.Myotome of C6-7 (Repeat Question)A. Wrist flexion and extension

32. SF86 Most common cause of maternal cardiac arrest A. PE B. AFE C. Haemorrhage D. PreeclampsiaE. cardiomyopathy

33.Most likely change on CTG with anaesthesia for non-obstetric surgery at 32 wksA. Loss of beat to beat variability B. No changeC. Late decelsD. Variable DeccelsE. uterine contractionsCTG can be used from about 18-20 weeks gestation. Fetal heart rate (FHR) variability is present by 25-27 weeks. The most likely thing in non-obstetric surgery during pregnancy is that the CTG will not change (assuming all goes well with the surgery, and the mother's physiology is maintained close to normal). However, the most common signs of fetal distress will be a change in the baseline FHR, and loss of beat-to-beat variability. If this occurs you should assess and correct any maternal physiologic parameters that are abnormal. (Answer=B). Ref: Chestnut's Obstetric Anesthesia: Principles and Practice (4th Edn), Chestnut, Polley, Tsen, Wong. Mosby, 2009; p. 352.

Reference: Practical Approach to Obstetric Anesthesia 2009 p84:

Consider A-Loss of beat to beat variability:

Normal CTG under GA = Loss of beat to beat variability, no decelerations.

Normal CTG under neuraxial block without sedation = No change

34.What is NOT associated with ulcerative colitis? (Repeat question)A. Cirrhosis B. Psoriasis C. ArthritisD. E.

IBD (and specifically UC) is associated with arthritis - more commonly in Crohn's (C=True, and NOT the answer). Colectomy usually cures arthritis. IBD is also associated with Primary Sclerosing Cholangitis (PSC) which "frequently" leads to cirrhosis and hepatic failure (A=True and NOT the answer). Dermatologic associations of IBD include erythema nodosum, pyoderma gangrenosum, pyoderma vegetans, pyostomatitis vegetans, Sweet's syndrome, Psoriasis, and skin tags. Therefore B=True and also NOT the answer. Answer obviously one of the stems that was not remembered. Ref: Harrison's 16th edn, pp.1783-84.

35.What's the most appropriate mode for neuromuscular monitoring during aneurysm clipping? (repeat question)A. TOFCB. TOFratioC. Post tetanic count

36.What's the area burnt in man? Half of left upper arm, all of left leg and anterior abdomen (repeat qu).A. 27% B. 32% C. 42%D.E.

37.Torsades, what's not useful? (Repeat question)A. Amiodarone B. Isoprenaline C. D. E.

38.Treatment for long QTc (OR what does NOT increase the QT interval)A. MagnesiumB. ? C. ? D. ?

39.HOCM, VF arrest on induction, what's the first priority in management?A. defibrillate B. amiodaroneC. Intubate and ventilate D. Pre-cordial thump E. adrenaline

40.Pregnant woman presents with narrow complex tachycardia HR 190, stable BP 100/60. No response to vagal manoevures. Management?A. adenosine 6mg - this comes after vagal manoeuvres in the algorithmB. DCR C. amiodarone D. Atenolol E. ?

41.The intercostobrachial nerve: A. Arises from T2 trunk B. Is usually blocked in brachial plexus blockC. Supplies antecubital fossa D. can be damaged by torniquet E. Arises from inferior trunk

A. False. Arises from lat. cut. branch of 2nd intercostal nerve (from T2 originally, but not directly from the trunk)

B. False. It joins the medial cutaneous nerve of the arm which comes from the medial cord, but does not form part of the brachial plexus, and is not blocked in brachial plexus blocks.

C. False. Supplies medial side of upper arm, and joins medial cutaneous nerve of arm which supplies medial side of upper arm down to the elbow.

D. TRUE. Any nerve compressed by a tourniquet can be damaged. Would have to be high up the arm/close to axilla to compress it.

E. False. Not part of brachial plexus, or a branch from it. Arises from lat. cut. branch of 2nd intercostal nerve.

REF: Anatomy For Anaesthetists - Ellis, Feldman & Harrop-Griffiths (8th edn) - pp 182 and 317.

42.PDPH (thoracic epidural) of "low pressure type". Features NOT consistentA. headache Immediately after procedure B. Frontal headache only - FALSE and the answer as usually frontal and occipitalC. Starts 24hrs post D. Auditory symptoms E. Neck stiffness

A=FALSE. Usually starts 24-48 hrs after dural puncture. B=True. Typically fronto-occipital, but can be frontal, occipital or nuchal (Evidence-Based Obstetric Anaesthesia, Halpern & Douglas, BMJ Books; Blackwell, 2005; p.192) C=True. Most commonly starts 24-48 hrs later. D=True. Hearing loss and/or tinnitus are features. E=True. Neck stiffness and photophobia are common.

43.Labour epidurals increase maternal and fetal temperature. This results in neonatalA. Increased sepsis B. Increased investigations for sepsis C. increased non shivering thermogenesis D. Increased need for resuscitation E. Cerebral Palsy Labour epidural analgesia is associated with an increase in maternal core body temperature, but also with an increased neonatal temperature and fetal heart rate. Several studies have shown that labour epidural analgesia is associated with increased neonatal neonatal sepsis evaluations, but no increase in neonatal sepsis. Answer=B. Ref: Chestnut's Obstetric Anesthesia: Principles and Practice (4th Edn), Chestnut, Polley, Tsen, Wong. Mosby, 2009; p. 457.

44.Maternal cardiac arrest. in making the diagnosis of AFE, Large amount of PMNs surrounding foetal squamous cells are A. Pathonomonic B. Supportive C. Only found at postmortem D. Irrelevant E. Incidental A = False. No finding is pathognomonic of AFE. It is a diagnosis of exclusion. B = True. This finding (whether at post-mortem, or whether aspirated from pulmonary artery catheter in a surviving patient) is suggestive, but not pathognomonic. Fetal squames have been found in pulm. art. catheter aspirates in women with no evidence of AFE, and conversely there are reports where they have been unable to detect fetal squames in women diagnosed with AFE. The finding is suggestive/supportive only. C = False. Can be found in pulmonary artery aspirates in women still alive, and even with no symptoms. D = False. This finding is not irrelevant, but not diagnostic. It needs to be considered with all other clinical information. E = ? Given the less than ideal specificity of the test, one could argue that it is incidental, although the BJA CEACCP article states that it is suggestive of AFE, which implies it is more than an incidental finding. ANSWER=B. Refs: Chestnut's Obstetric Anesthesia: Principles and Practice (4th Edn), Chestnut, Polley, Tsen, Wong. Mosby, 2009; p. 845. and BJA CEACCP 2007; 7(5):152-56.

45.Jehovah's witness refusing blood products. The ethical principle you are honouring if you continue with elective hip operationA. Autonomy B. NonmaleficienceC. Justice D. Paternalism

Autonomy is the right of the patient to think/decide/act freely. The patient has the right to decide what treatment they do or don't want to have, and even if the doctor disagrees with their decision (and/or reasoning) the patient has the right to decide for themselves. Answer is A. It is Autonomy not to transfuse them if required, as per their wishes. it is Justice to afford them access to the same standard of health care as everone else. i think C.

46.An 86yo with severe dementia and multiple medical problems.. Surgeons want to operate for faecal peritonitis/bowel perforation, and believe he will die without the surgery. Your decision NOT proceed with surgery is supported by which ethical principle?A. Dignity B. Competence C. Non-maleficience D. Paternalism E. Futility

47.Inserted DLT. FOB down tracheal lumen. What feature is most helpful in identifying Left vs Right main bronchusA. Trachealis muscle B. "there are 3 lobes in right lung"C. LMB longer than rightD. Angle of RMB vs left E. Three segments of RUL

48.You are performing a bronchoscopy, but are unsure of your location. Then you see trifurcation of bronchi. Most likely location is: A. Right upper lobe B. RMLC. RLLD. LULE. Lingula <br

49.Elimination Half life of Tirofiban A. 2hrs B. 8hrs C. 12hrs D. 24hrs E. 15 minutes "Stoelting" and "Anesthetic Pharmacology" both state that the half life of tirofiban is in the order of 2-4 hours.

50.POISE trial showed A. Increase CVA B. Anaphylaxis C. renal failure D. Increased AMI

51.Why is codeine not used in paedsA. Poor taste B. High inter-individual pharmacokinetic variability C. Not licensed for <10yo

D. not as effective as adult when given in ?weight adjusted dose?A. FALSE - as far as I am aware it doesn't have a particularly nasty taste, and is used in cough

suppressants, so FALSE. B. TRUE - Variations in CYP2D6 function affect how much codeine is converted to morphine,

and therefore how effective it is, but also how "sensitive" patients are to codeine. (?10% of caucasian population are poor metabolisers)

C. FALSED. FALSE

52.Patient on table for phaeochromocytoma with GA and epidural insitu. Pt on phenoxybenzamine and metoprolol preop, high dose nitroprusside and phentolamine. BP still high ?250/-. Next step A. IV hydralazine B. IV Magnesium C. Propofol D. Epidural lignocaine bolusE. Esmolol

A - ?FALSE. Duration of action may be a problem, as once tumour is out you may need a vasopressor and won't want the hydralazine hanging around. Plasma half-life is 2-3 hours (significantly more in renal impairment, but may be less in "rapid acetylators"). Anyway, 4 half-lives is 8-12 hours (less if you're a fast acetylator), and that's not ideal. B - TRUE. Oxford Handbook says this is a good option. C - False. Not the best option. D - False. Epidural bolus will not negate the effects of circulating vasoactive catecholamines. also the duration is likely to be in the order of hoursE - False. Esmolol for tachycardia, but not for BP control.

53.25 yo primip ?38/40 gestation with beta thalassemia trait for epidural. BP 140/95, mild proteinuria ...something else... Best test before you will put in epiduralA. Coagulation screen B. Hb C. Platelet count D. skin bleeding timeE. Thalassemia trait is a red-herring. No effect on clotting/epidural placement. Money is on pre-eclampsia Main thing to look at is the platelet count. Answer is C. See Oxford Handbook 2nd edn - p.744. - If plt>100, proceed. - If plt<100, do coags. - If plt 80-100, and coags normal - regional is OK.

54.Another pregnant lady ?39/40 with BP185/115 , 4+proteinuria, clonus. IDC placed, 10mLs of dark coloured urine only for the last few hours. Initial managementA. 500mL Crystalloid bolusB. IV hydralazine - this is the priority here - aim for <160 with hydralazine 5mg IV Q15min/PRNC. IV Magnesium - this would be second jobD. insert epidural - not before assessment of coagulation profile

55.Best agent to decrease gastric volume AND increase gastric pH before semi-urgent procedureA. Omeprazole B. Cimetidine

C. Ranitidine - IV ranitidine works within 40mins and lasts several hours and is part of the SIG obs guideline (you would also give sodium citrate)D. Sodium citrate

From the ANZCA Obstetric SIG - Ranitidine has been the most extensively studied (Escolano et al 1996, Level II; Lin et al 1996, Level II; Rout et al 1992, Level II). To date, no other agent has been consistently demonstrated to be more effective than ranitidine and most are more expensive. A number of studies have been done in the non-obstetric elective surgery setting. Maltby et al (1990, Level II) showed that 150 mg of oral rantitidine when given two to three hours before surgery resulted in a mean gastric pH of 5.86 (+/- 1.73) and with only one out of 49 patients having an ‘at risk’ combination of pH <2.5 plus gastric volume of >25 mL.

This doesn't however say specifically that the volume and pH are better than others... It also says that Sodium citrate is the most effective agent for immediate neutralisation of acidic gastric content. The reported effects on gastric volume are inconsistent with either no change (Dewan et al 1985, Level II) or a slight increase (Jasson et al 1989, Level II; Yau et al 1992; Level II

56.Most common congenital heart disease (repeat)A. VSDB. PDAC. ? D. ? ACYANOTIC defects: VSD=35%, ASD=9%, PDA=8%, Pulm. stenosis=8%, Aortic stenosis=6%, Coarctation=6%, Atrioventricular septal defect=3% CYANOTIC defects: Tetralogy=5%, Transposition=4%

57.Active 4 year old. Ts & As. Continuous murmur, disappears on lying down (repeat) A. Venous hum

Acetylcholine receptors are down regulated in A. Guillain-Barre syndrome B. Organophosphate poisoning C. Spinal cord injury D. Stroke E. Prolonged NMBD use

A - False. Effectively a denervation injury which causes UP-regulation. B - TRUE. Organophosphate poisoning causes increases in miniature-end-plate potential (MEPP), and thus can cause DOWN-regulation of ACh receptors. Apparently continuous exposure to organophosphates can cause degeneration of pre-junctional and post-junctional structures. C - False. Denervation causes UP-regulation. D - False. As for spinal cord injury. E - Prolonged NMBD use can cause UP-regulation of ACh receptors. REFS: Miller (7th edn) - p.358

58.Myaesthenia gravis - features predicting need for post op ventilation EXCEPT A. Prolonged diseaseB. High dose RxC. Previous respiratory crisisD. Increased sensitivity to NMB's - they will all be sensitive

E. bulbar dysfunctionReference: CEPD Reviews 2002 p88- and OHA 246-

risk factors for IPPV postop (thymectomy) are: 1. FVC<2.9L2. Concommitant COAD3. Acute fulminant crisis or respiratory involvement (grade 3)4. Myasthenic crisis (grade 4)5. OHA adds:

a. Duration of disease >6yrs b. Pyridostigmine dose >750mg/d c. Major body cavity surgery d. Bulbar palsy that is predictive of intra and postop airway protection.

59.Diagnositic Utility of BNP best in (repeat) A. SOB post pneumonectomy dyspnoea B. Confusion post CABG

60.Innervation of Larynx (repeat)A. the internal branch of the superior branch of the...B.C.D.E. Cuff compression of recurrent laryngeal nerve against thryoid can cause palsy

61.Which is not a branch of the mandibular nerve (repeat)A. AuricultemporalB. Great Auricular – superficial cervical plexusC. ?

62.Reason not to operate liver injury(repeat)A. Haemodynamically stableB. Low grade injury on CTC. ?

63.World Federation Neurosurgeons (repeat)A. No improvement cooling Grade I to IIIB. ?C. ?

64.Most distant anatomy seen on grade III laryngoscopyA. soft palate B. hard palate C. EpiglottisD. arytenoid cartillage E. opening to ?

65.Text Re: Trauma pt, Head Injury GCS 5, high ICPs, best management for ortho procedure(repeat)A. Propofol/fentanylB. Propofol / nitrousC. Other options with volatiles

66.Drug NOT used to treat acute intermittent porphyria - question was: person with AIP given ?something and triggered a seizure, what not to use (repeat)A. MorphineB. PhenytoinMost anticonvulsants are contraindicated (such as phenytoin, carbamazepine, thiopentone) because they induce hepatic P450 enzymes. (This consumes heme and thus reduces the negative feedback on ALA synthesase which is then free to generate heme/porphyrins products.) Drugs considered safe to use in convulsing porphyriacs include: midazolam, propofol, gabapentin and magnesium.

67.Regarding anticholinesterases:A. pyridostigmine has slow onset of effectB. physostigmine does not rely on renal metabolism/excretionC. neostigmine cannot reverse centrally acting cholinergicsD. edrophonium is less reliable in reversal?

68.rpt question about multiple sclerosis (rpt):A. exacerbated with heat

69.rpt question about signs seen in sarin poisoning (rpt):A. mm fasciculationB. dry skin

70.nerve to block for painful meralgia parastheticaA. lateral femoral cutaneous nerveB. femoral nerve

71.paternal uncle has MH, pregnant lady, how best to test for MH (rpt q)A. muscle biopsy on pregnant ladyB. negative muscle biopsy of her fatherC. genetic testing of pregnant lady

72.The nerve supplying area of skin between greater trochanter and iliac crest:A. subcostal nerveB. ilioinguinal nerveC. genitofemoral nerveD. femoral nerveE. lat cutaneous femoral nerve

The lateral cutaneous branch of the last thoracic nerve is large, and does not divide into an anterior and a posterior branch. It perforates the Obliqui internus and externus, descends over the iliac crest in front of the lateral cutaneous branch of the iliohypogastric (Fig. 819), and is distributed to the skin of the front part of the gluteal region, some of its filaments extending as low as the greater trochanter. http://education.yahoo.com/reference/gray/illustrations/figure?id=820 When you look at the assoc. picture, it looks like this nerve will supply this bit skin (Lat cut br of the 12th Thoracic nerve).

73.Hydroxyethylstarch with intermediate volume replacement/ duration(rpt):A. 6% HES 130/0.4

74.Pyloric stenosis (rpt Q)A. alkaline then acid urineB. ?C. ?

75.Which can deliver minute ventilation of greater than 5L/min using a 14 G cannula used for needle cricothyroidotomyA. jet ventilation using pressure 400KPAB. oxygen flush button on anaesthetic machineC. oxygen tubing on oxygen port on anaesthetic machine at 12L/minD. E. none of the above

76.congenital diaphragmatic hernia (rpt)A. "there is hyperplasia of pulmonary arterioles"B.

77.young man in trauma, hypotensive ?BP70/40. CXR widened mediastinum. Fast STRONGLY POSITIVE. "best way to assess the widened mediastinum is" (rpt)A. intraop TOEB. TTE

78.IV paracetamolA. late plasma levels around the same as oralB. highly protein boundC. ?30%? renally excretedD. VD 10L/kg

A. TRUEB. FALSE - PPB 0-5%C. FALSE - renal excretion unchanged < 2%D. FALSE - Vd = 1L/kg

79.Head Trauma patient with unilateral dialated pupil, wahts the diagnosis ?A.Global injuryB.Optic nerve injuryC.Horners syndromeD.Tenstentorial herniation - with CNIII stretchE.....

80. Question about CO2 Laser. Does not cause deep tissue damage becausea. High Frequencyb. Penumbra effectc. ? Dissipation of energyde.

81. Patient with diastolic dysfunction. Is it caused by:a. Restrictive cardiomyopathyb. Dilated cardiomyopathyc. d.e.

82. supine hypotension syndrome (rpt)a. high SVRb. tachycardia

83.Non-normally distributed pain scores. What is the best way to describe spread of data?A. Inter-quartile rangeB. Standard deviationC. Standard error of the meanD. ?E. ?

84.What term means the number of people who are correctly identified as not having a disease:A. SensitivityB. SpecificityC. Positive predictive valueD. Negative predictive value

85.If a test is negative, what proportion will not have the disease:A. SensitivityB. SpecificityC. Positive Predictive ValueD. Negative Predictive Value

86. Cryoppt: insufficient (rpt)A. F9B. F13

87. Most likely to result in myocardial infarction (rpt):A. intraop myocardial ischaemiaB. post op myocardial ischaemia

88.Awake patient with diabetes insipidusA. EuvolaemicB.C.D.E. urinary Na <20 (not enough ADH and large consequent free water diuresis with low urinary sodium and hypernatraemia)

89.Indication for percutaneous closure of ASDa. Primun < 3cm (primum may involve the atrioventricular valves and are an endocardial cushion defect that is usually corrected surgically)b. Primun > 3cmc. Secundum < 3 cmd. Secundum > 3cme. sinus venosus ASD

90.Timing of worst coagulopathy after liver transplant a. 1-2 days b. 3-4 days c. 5-6 days annoyingly the OHA says 2-3days!

91.ASA grading was introduced toA. predict intraop anaesthetic risk

B. Predict intraop surgical and anaesthetic riskC. Standardise the physical status classification of patientsD. Predict periop anaesthetic riskE. Predict periop anaesthetic and surgical risk

92.Pulsus paradoxus is: (the Q was something like - severe asthmatic - when take BP you would find)A. Reduced BP on inspiration unlike normal (ie normally increased on insp)B. Reduced BP on inspiration exaggerated from normalC. Reduced BP on expiration unlike normalD. Reduced BP on expiration exaggerated from normalE. ?

92.Respiratory function in quadriplegics is improved byA. abdominal distensionB. an increase in chest wall spasticity - this splints their chest wall and prevents "flail" with diaphragmatic descentC. interscalene nerve blockD. the upright positionE. unilateral compliance reduction

93.An INCORRECT statement regarding the autonomic nervous system is thatA. autonomic dysfunction is a predictor for worse long term survival after myocardial infarctionB. heart rate responses are primarily mediated through the sympathetic nervous systemC. inhalation anaesthetics all impair autonomic reflex responsesD. autonomic dysfunction is a predictor for haemodynamic instability following anaesthetic inductionE. low heart rate variability is associated with worse cardiac outcomes following non-cardiac surgery

94.Correct statements regarding expiratory-inspiratory flow-volume loops include all of the following EXCEPT A. in obstructive disease the expiratory curve has a scooped out or concave appearance B. in restrictive disease expiratory flows are usually decreased in relation to lung volumeC. in restrictive disease the expiratory curve has a convex appearance D. the expiratory curve is largely effort independent E. the inspiratory curve is effort dependent

95.Carbon dioxide is the most common gas used for insufflation for laparoscopy because itA. is cheap and readily availableB. is slow to be absorbed from the peritoneum and thus saferC. is not as dangerous as some other gases if inadvertently given intravenouslyD. provides the best surgical conditions for vision and diathermyE. will not produce any problems with gas emboli as it dissolves rapidly in blood

96. Following a cadaveric renal transplant under general anaesthesia, your patient's plasma K+ increases to 6.0 mmol.l-1 in recovery after being 5.0 mmol.l-1 pre and intra-operatively. This patient requires (this is where i'm talking about figments of imagination - i'm pretty sure this paper had the version where RR 8/min, what is the most likely cause etc etc)A. an intravenous infusion of CaCl2 (10 mls over 20 minutes) this is still just moderate hyperkalaemia and in the absence of ECG changes this is not yet necessaryB. arterial blood gases to ascertain the acid/base statusC. potassium exchange resins rectally - temporising measure to help the cadaveric kidney outD. sodium bicarbonate infusion (50- 100 mEq over 5- 10 minutes) - only if acidoticE. urgent haemodialysis - if temporising measures fail and kidney does not kick in

97. Carcinoid syndrome - finding on examining heart:A. Fine inspiratory crepitationsB. Systolic murmur at apexC. Systolic murmur at left sternal edge - classical L heart valvular disease D. Murmur at apex with opening snapE. Pericardial rub

98.Histamine release in anaphylaxis does NOT cause: A. TachycardiaB. Myocardial depressionC. Coronary artery vasodilatationD. Prolonged PR intervalE. Decreased impulse conduction

99.Pre-ganglionic sympathetic fibres pass to the A. otic ganglion - has post ganglionic sympathetic fibres from around middle meningeal arteryB. carotid body - glossopharyngeal (parasympathetic)C. ciliary ganglion (sympathetic fibres pass through the ganglion but do not synapse there and they're post ganglionic)D. coeliac ganglion - part of the sympathetic prevertebral chain so pre-ganglionic fibres pass to itE. all of the above

100.Branches of the mandibular nerve do NOT include theA. auriculotemporal nerveB. long buccal nerveC. lingual nerveD. great auricular nerveE. chorda tympani nerve - facial nerveThe chorda tympani is a nerve that branches from the facial nerve (cranial nerve VII) inside the facial canal, just before the facial nerve exits the skull via the stylomastoid foramen. Chorda tympani is a branch of the facial nerve (the seventh cranial nerve) that serves the taste buds in the front of the tongue, runs through the middle ear, and carries taste messages to the brain. (Wikipedia) Disco 30/6/10

101. In a trial, 75 patients with an uncommon, newly described complication and 50 matched patients without this complication are selected for comparison of their exposure to a new drug. The results show

Complication present Complication absent

Exposed to new drug 50 25NOT exposed 25 25

From this dataA. the relative risk of this complication with drug exposure CANNOT be determined (retrospective)B. the odds ratio of this complication with drug exposure CANNOT be determinedC. the relative risk of this complication with drug exposure is 2D. the odds ratio of this complication with drug exposure is 1.33 E. none of the above

A. TRUE - this study is a retrospective case control and RR is not used rather ORB. FALSE - OR calculation is appropriateC. FALSE - RR not relevant

D. FALSE - OR = 2E. FALSE

102.BP measurement - overestimates with:A. big (wide) cuff - underestimatesB. skinny arm - underestimatesC. severely peripherally vasoconstricted D. atherosclerosis (it was arteriosclerosis - yes indeed) - rigid artery → cuff pressure must be higher to compress themE. slow cuff deflation - false fast deflation will overestimate DBP and underestimate SBP

103. A device that detects a 10mA difference in active and neutral leads and causes turning off of the circuit within 40 ms. this is a :A. Class 1 deviceB. Equipotential earthingC. LIMD. Residual Current DeviceE. Fuse

104.Post-transfusion hepatitis in Australia is associated with A. jaundice in over 50% of patients B. development of chronic disease in less than 10% of patients - 85-90% will develop chronic HCVC. hepatitis B in the majority of patients - hep C in the majority although now it is 1 in 3.6million and HBV is 1 in a million.D. the presence of antigen or antibody to hepatitis C E. elevation of serum alkaline phosphatase - usually not elevated ie not a transaminase

105.In a patient requiring FFP where the patient’s blood group is unknown, it is ideal to give FFP of groupA. AB. BC. AB - would argue that these people do not have Abs to ABO antigens ie less risk of a reactionD. OE. Blood group of FFP in this situation does not matter

106.Features of the transurethral resection of the prostate (TURP) syndrome include all of the following EXCEPTA. agitationB. anginaC. bradycardiaD. nauseaE. tinnitus

107.The most frequently reported clinical sign in malignant hyperpyrexia isA. arrhythmiaB. cyanosisC. sweatingD. tachycardia + ↑ETCO2 (after MMS)E. rigidity

108.Which of the following is not an absolute contra-indication for MRI?A. cochlear implant - B. heart valve prosthesis - fixed to fibrous tissueC. ICD - malfunction likely

D. pacemaker - malfunction likelyE. intracranial clips - if ferromagnetic

109.Reverse splitting of the second heart sound occurs with: A. LBBB B. Pulmonary hypertension - will tend to cause narrowed normal splitting ie less P2 delayC. Acute pulmonary embolus - congestion will cause larger end-diastolic volumes and ejection will take longer (normal split despite increased PA pressures)D. ASD - will cause a fixed split that does not vary with respiratory cycleE. Severe MR - will tend to accentuate normal split owing to faster LV ejection

physiologic splitting occurs on inspiration owing to entrainment of blood into the RV relative to the LV. RV ejection then takes longer resulting in a slightly delayed P2. On expiration this is minimise owing to the opposite effect.reverse splitting occurs with LBBB, PPM (where uncoordinated ventricular ejection causes P2 to go first), AS or HOCM (prolonged LV ejection)

110.Atrial fibrillation:A. Cardioversion results in longer life expectency than rate controlB. Need to stay on warfarin following cardioversionC. Pt with HR <80 generally do not require anticoagulationD.

111.Scoliosis surgery. what is incorrectA. one third of the blood loss occurs postoperatively B. major blood loss is frequently accompanied by a consumptive coagulopathy C. surgery will halt progression of the restrictive lung deficit D. the major neurological deficits that occur are usually due to damage to the posterior columns of the spinal cord - would have thought that anterior spine is more vulnerable in the setting of hypoperfusion of anterior spinal artery territory E. the use of aprotinin reduces blood loss

114. Difference between cardiac protected and body protected areaA. Equipotential earthing

115. Which hormone is not released during surgery?A. cortisolB. C. TSHD. growth hormone

116. Asystolic aortic arch repair. The best method for cerebral protection is:A. anterograde perfusion via coronary vesselB. retrograde perfusion via jugular veinC. thiopentone IVD. hypothermia to 20 degrees celcius

117. Specificity most closely meansA. chance of a positive test in people with the diseaseB. chance of a negative test in people without diseaseC. chance of...

118. Negative predictive value most closely meansA. chance of a positive test in people with the diseaseB. chance of a negative test in people without diseaseC. chance of ...(NB there were definitely two questions with identical options a. through e. (and each option was wordy and a bit confusing). The stems were definitely specificity and NPV)

119. Performing a bronchoscopy. The best way to orient the scope is: (see Q48)A. angle of the bronchusB. length of the bronchusc. RULD. trachealis muscle (posterior)

120. Symptoms of hypercalcaemia include: (see Q5)A.B.C. seizures - coma onlyD. short ST segment - FALSE, shortening of QT interval + prolonged PR + QRS prolongation + T wave flattening + heart block + digoxin accentuation

features of hypercalcaemia1. weakness/N+V/lethargy/metal changes/coma2. ECG changes above

treatment1. rehydrate2. frusemide diuresis3. palmidronate (long lasting)4. calcitonin → ↓ Ca and PO4 secretion from bone (transient)5. hydrocortisone 200-400mg IV (if secondary to malignancy)6. HD if secondary to renal failure

121. Paediatric VF arrest. Which is true?A. if resistant to defibrillation should give amiodarone 5mg/kgB.C. commonly associated with respiratory arrestD. is the most common form of arrest in this patient groupE. should defibrillate with 5J/kg - false 2 and then 4J/kg

123. OLV hypoxaemia. After 100% O2 and FOB next step is: (rpt)A. CPAP 5cm top lung - this will allow oxygen insufflation and slight distension of the non-dependent lung/you get 150mL TV with contralateral lung insufflation anyway. this is a good start (could increase to 10cmH2OB. CPAP 10cm top lungC. PEEP 5cm bottom lung - will increase shunt to non-dependent lung (this is a desperate manoeuvre)D. CPAP 5cm top + PEEP 5cm bottom

one lung ventilation CEACCP 2002surgical indications:

1. lung2. oesophageal3. mediastinal

4. spinalpre-operative assessment

attempts to determine the patient's ability to tolerate OLV and possible lung resection assess assuming pneumonectomy since

o disease may be more extensive than expectedo oedema + atelectasis → post op lung function may be significantly impaired

Hxo functional capacity

SOB at rest (NYHA IV) or cor pulmonale → bodes poorlyo cardiac problems

investigationso spirometry

FEV1 < 2L → probability of postop respiratory failure → 40%

o ABG - hypoxia at rest poor predictor/hypercapnia indicates respiratory failureo evaluation of individual lung function

technetium scanning to determine the post operative FEV1. FEV1 < 0.85L associated with respiratory failure post op

o pulmonary artery catheterisation and occlusion of the artery on the proposed side of the pneumonectomy, will test the remaining lung.

PA pressure > 40mmHg or PaO2 < 45mmHg or PCO2 > 60mmHg → survival unlikely

dicey testphysiology of OLV

lateral decubitus → V/Q mismatcho 60% flow to dependent lung BUT more ventilation to non-dependent lungo ↓ compliance and FRC of dependent lung owing to weight of mediastinum +

elevated position of diaphragm (abdominal contents pushing up) open chest

o ↑ compliance of non-dependent lung → ↑ dead space of non-dependent lung + ↑ shunt in dependent lung (A-a gradient ↑)

collapse of non-dependent lung → shunt if minute ventilation remains constant there will be a small increase in pCO2 owing to

reduced ventilation in theory with OLV, a shunt fraction of 50% is possible, that cannot be treated with ↑FiO2.

in reality several factors reduce this to about 20% of the pulmonary blood flow:o increased perfusion of dependent lung

o collapse of the non-dependent lung causes mechanical obstruction to circulationo HPV causes shunt to dependent lung

factors affecting pulmonary BFo volatiles

1MAC isoflurane → 20% ↓HPV N2O only 10% ↓HPV

o IV anaesthesia - no affect on HPVo vasodilators ↓HPVo vasoconstrictors constrict vessels in the dependent lung and increase BF to non-

dependent lung and shunt fraction (dopamine may do this less and is the first choice if vasopressor is required)

o ↑FiO2 → ↓PVR in dependent lung (favourable) o CO -

↑CO → recruitment and distension in the non-dependent lung → ↑shunt ↓CO → ↓Sv02 → ↓SaO2 if shunt fraction large

o PEEP ↑PVR → ↑ flow to non-dependent lung → ↑shunt

conduct of anaesthesia GA with controlled ventilation goals

o blunt airway reflexes - remifentanilo minimise HPV inhibition - propofol TIVA (no demonstration clinical benefit but

theoretically sound)o maintain haemodynamic stabilityo rapid offset drugs to avoid prolonged ventilation post op - remifentanil and TIVAo good post operative analgesia

thoracic epidural - large meta-analysis showed ↓atelectasis ↓LRTIs ↓pulmonary complications

paravertebral catheter (Sx or anaesthetic percutaneous) intercostal blocks at the start to avoid opioids during surgery

o restrictive fluid administration → better lung outcomes; vasopressor might be a better choice

practical aspectso DLT

MALE - 39-41Fr FEMALE - 37-39Fr children - 26Fr OK for 8-10yrs L sided DLT more commonly used - L bronchus is longer and so less chance of

obstructing the L upper lobe bronchus than a R DLT on the R obstructing the R upper lobe bronchus

contraindications incl. L bronchial lesions/L bronch stump clinical manoeuvres include auscultation and clamping fibreoptic bronchoscopic evaluation gold std - want to see the blue cuff just

beyond the carinao bronchial blockers

children (DLT too big) normal ETT then bronchoscopic placement of blocker

o single lumen ETT eg for TOF or bleeding lung

eureka type intubation for R main for L main - turn child's head to R and advanced the ETT with the concavity

facing posteriorlyo equipment

invasive BP CVL temperature spirometry - for pressure/volume loops OLV - ↓TV and ↑RR 20%

permissive hypercapnia to avoid barotraumao resus - treatment of hypoxia on OLV

100% oxygen let surgeon know check tube postition for slip +/- bronch eg cuff herniation check circuit check CO insufflate non-dependent lung with oxygen (TV of 150mL/min due to

contralateral lung ventilation small amounts of PEEP can be applied to the non-dependent lung

with a flow rate of 1L/min (Ayres T-piece can be used here) CPAP to non-dependent lung (5-10cmH2O) → distension of non-dependent

lung but no haemodynamic instability/surgical interference (can do this with the ambibag

consider PEEP to ventilated lung → ↑FRC and shifts the lung up to the steeper part of the compliance curve allowing better volume for a given pressure BUT ↑PEEP → ↑PVR → ↑flow to non-dependent lung + ↑ shunt. This needs to be balanced carefully

ultimately intermittent ventilation of the non-dependent lung may be required

surgical clamping of the non-dependent PA will eliminate shunt.