anaesthetic management of obstetric emergencies

Dr sheeba hakakWaterford regional hospital

Definition

Obstetrical emergencies are life-threatening medical conditions that occur in pregnancy or during or after labor and delivery.

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Massive obstetric haemorrhage1. MOH is a major cause of maternal death and

morbidity2. Variably defined as; . blood loss >1500ml . decrease in hb >4g/dl or .acute transfusion requirements >4 units3. The gravid uterus receives up to 12% of cardiac

output ,thus OH can be un expected and rapidly become life threatening.

Classification

Antepartum placenta previa/accreta placental

abruption uterine rupture

Post partum uterine inversion uterine atony birth trauma or

laceration

ANTEPARTUM HEMORRHAGE

Per vagina blood loss after 20 weeks’ gestation.

Complicates close to 4% of all pregnancies and is a MEDICAL EMERGENCY!

Is one of the leading causes of antepartum hospitalization, maternal morbidity, and operative intervention.

Placenta Previa

Defined as a placenta implanted in the lower segment of the uterus, presenting ahead of the leading pole of the fetus.

1. Total placenta previa. The internal cervical os is covered completely by placenta.

2. Partial placenta previa. The internal os is partially covered by placenta.

3. Marginal placenta previa. The edge of the placenta is at the margin of the internal os.

4. Low-lying placenta. The placenta is implanted in the lower uterine segment such that the placenta edge actually does not reach the internal os but is in close proximity to it

Placenta Previa

Incidence about 1 in 300

Perinatal morbidity and mortality are primarily related to the complications of prematurity, because the hemorrhage is maternal.

Etiology

Advancing maternal age Multiparity Multifetal gestations Prior cesarean delivery Smoking Prior placenta previa

Placenta Previa

The most characteristic event in placenta previa is painless hemorrhage.

This usually occurs near the end of or after the second trimester.

The initial bleeding is rarely so profuse as to prove fatal.

It usually ceases spontaneously, only to recur.

Placenta Previa

Placenta previa may be associated with placenta accreta, placenta increta or percreta.

Coagulopathy is rare with placenta previa.

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Diagnosis.

Placenta previa or abruption should always be suspected in women with uterine bleeding during the latter half of pregnancy.

The possibility of placenta previa should not be dismissed until appropriate evaluation, including sonography, has clearly proved its absence.

The diagnosis of placenta previa can seldom be established firmly by clinical examination. Such examination of the cervix is never permissible unless the woman is in an operating room with all the preparations for immediate cesarean delivery, because even the gentlest examination of this sort can cause torrential hemorrhage.

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The simplest and safest method of placental localization is provided by transabdominal sonography.

Transvaginal ultrasonography has substantively improved diagnostic accuracy of placenta previa.

MRI

At 18 weeks, 5-10% of placentas are low lying. Most ‘migrate’ with development of the lower uterine segment

Placenta PreviaManagement Admit to hospital

NO VAGINAL EXAMINATIONNO VAGINAL EXAMINATION

IV access

Placental localization

Placenta PreviaManagement

Severe bleeding

Caesarean section

Moderate bleeding

Gestation>34/52

<34/52

ResuscitateSteroids Unstable

Stable

Resuscitate

Mild

bleeding Gestation<36/52

Conservative care

>36/52

Anaesthetic management for previa Examine the airway in case emergency G/A

is required and provide aspiration prophylaxis

Ask OB about involvement with any previous cesarean scar on ultrasound [risk of accreta]

Place two large bore IV lines and have warmers available.

Assure that blood is type and cross matched.

What type of anaesthetic?

Anaesthetic management of previa A review of 514 women with placenta

prtevia found: No difference between G/A or regional

anaesthesia in anaesthetic or operative complications.

G/A was associated with increased EBL and transfusions and decreased post op Hgb.

Am J Obstet Gyn 1999;180:1432

Anaesthetic management for previa A retros pective review 350 consective cases

of plcenta previa [ 60% using regional anaesthesia, 40% using G/A found:

. decreased EBL with regional vs G/A

. decreased transfusion with regional.

. no diff in incidence of hypotension. .two spinals were converted to G/A

secondry to c-hyst. Br J Anaesth 2000;84;725

Interventional radiology

Prenatal diagnosis of palcenta accreta/percreta is now becoming more common[vs diagnosis at delivery]

Have a care conference in advance with anaesthesiology ,OB,nursing and interventional radiology present.

Placental Abruption

Defined as the premature separation of the normally implanted placenta.

Occurs in 1-2% of all pregnancies

Perinatal mortality rate associated with placental abruption was 119 per 1000 births compared with 8.2 per 1000 for all others.

Placental Abruption

external hemorrhage concealed hemorrhage Total Partial

Risk factors for abruption Hypertension,chronic or pregnancy-

induced Age>35yrs Multiparity Smoking Cocaine use Abdominal trauma Premature rupture of membranes Hx of previous abruption

Diagnosis of abruption

Vaginal bleeding with abdominal pain

Uterine hypertonicity Fetal distress Retroplacental clot The presentation can be quite

variable and difficult to diagnose

OB management of abruption Evaluate maternal stability[vital

signs,coagulation studies] Evaluate fetal well-being and

maturity If severe fetal distress and/or

maternal instability ...........urgent C/S If stable mother and

fetus......induction of labor and vaginal delivery

Anaesthetic management of abruption Assure good IV access and

availability. Regional techniques are appropriate

if maternal volume staus and coags normal

If G/A is indicated,consider induction with etomidate or ketamine

Have several oxytocics available for treatment of uterine atony.

Uterine rupture

Risk factors for uterine rupture Previous uterine surgery Abdominal trauma Uterine trauma Grand multiparity Fetal macrosomia Fetal malposition

Diagnosis of uterine rupture Fetal distress Cessation of uterine contraction [ in

labor] Vaginal bleeding Abdominal pain

OB management of uterine rupture Uterine repair. Hysterectomy ANAESTHETIC MANAGEMENT. Depends on ease of repair ,but be

prepared for G/A and volume replacement.

PPH

The mean blood loss in a vaginal delivery is 500 ml & 1000 ml for cesarean section.

Definition: Blood loss greater than 500 ml for vaginal and

1000 ml for cesarean delivery. However, clinical estimation of the amount of

blood loss is notoriously inaccurate. Another proposed definition for PPH is a 10%

drop in haematocrit.

PPH Risk Factors

PPH Risk Factors

PPH Risk Factors

PREVENTION OF PPH

Although any woman can experience a PPH, the presence of risk factors makes it more likely.

For women with such risk factors, consideration should be given to extra precautions such as: IV access Coagulation studies Crossmatching of blood Anaesthesia backup Referral to a tertiary centre

OB MANAGEMENT OF PPH

Bimanual uterine compression and massage

Infusion of oxytocin Evaluation for retained placenta Use of other oxytocics

ANAESTHETIC MANAGEMENT OF PPH1. Volume resuscitation large bore IVs ,monitors,warmers2. Analgesia pre existing epidural,ketamine,G/A3. Oxytocics4. Move to OT sooner rather than later.5. Consider notifying interventional

radiology.

Oxytocic drugs

Drug/dose Oxytocin 20-80u/l Methergine 0.2mg

IM

Hemabate ..prostagladin F2alpha 250 mcg IM

Side effects vasodialation with

IV bolus,hyponatremia

Diffuse vasoconstriction,pulmonary and systemic htn,coronary vasospasm,nausea

Broncho spasm,pul htn,hypoxia,nausea,diarrhoea.

PRE ECLAMPSIA

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Definitions of Hypertensive Disorders in Pregnancy [1,2,4,5] Preeclampsia

Blood pressure elevation with proteinuria Occurs after 20 weeks of gestation Proteinuria

urinary excretion of 300 mg or greater of protein in 24 hr

Edema no longer diagnostic for poor specificity

Eclampsia seizures

Definitions of Hypertensive Disorders in Pregnancy [1,2,4,9] HELLP syndrome

defined by the presence of all 3 criteria: Hemolysis (abnormal peripheral

smear, bilirubin 1.2 mg/dL [20.5 µmol/L], or lactate dehydrogenase 600 IU/L)

Elevated liver enzymes (aspartate aminotransferase 2 x normal)

Thrombocytopenia (platelets <100 x 103/µL)

Aetiology

Exact aetiology unknown Possible causes 1. widespread endothelial

dysfunction leading to placental ischemia and multi organ dysfunction

2. synthesis of many substances like NO and PGI2 may be decreased in pre ecclampsia which leads to smooth muscle reactivity and platelet adhesion

Complications

Neurological Headache Visual disturbances Hyperexcitability Seizures Intracranial hemorrhage Cerebral edema

Pulmonary  Upper airway edema Pulmonary edema

Cardiovascular  Decreased intravascular volume Increased arteriolar resistance Hypertension Heart failure

Complications

Hepatic  Impaired function Elevated enzymes Hematoma Rupture

Renal  Proteinuria Sodium retention Decreased glomerular filtration Renal failure

Hematological  Coagulopathy

    Thrombocytopenia     Platelet dysfunction     Prolonged partial thromboplastin time

Microangiopathic hemolysis

Risk Factors [10]

Obesity Black race Chronic hypertension

Diabetes or insulin resistance Collagen vascular disease Thrombophilias Increased circulating testosterone Multiple gestation Previous preeclampsia

Management

Definitive treatment of preeclampsia is delivery

Whether or not to deliver the fetus gestational age maternal and fetal condition severity of preeclampsia

Patients at term delivered Remote from term Conservative approach Delivery at any gestational age

Maternal end-organ dysfunction Nonreassuring tests of fetal well-being

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Mgso4

Anticonvulsant of choice in preventing and treating fits.

Iv bolus 4 to 6 gms and then Infusion 1 to 2 gms/hr to keep sr mg in

therapeutic range [2-3 mmol/lt] Indicators of mgso4 toxicity...... ECG changes [3-5mmol/lt] loss of deep TR [5 mmlol/lt] resp dep [6-7.5 mmol/lt] cardiac arrest [12 mmol/lt]

Anaesthetic considerations Pre anaesthetic assessment1 Fluid balance and hemodynamics .hypo albuminaemia,increased cap

permeability,high hydrostatic pressure leads to risk of pul and pharyngolaryngeal oedema

2. Estimation of cardiac out put ......if .....oliguria ,pul oedema,htn resistant to initial therapy.

Coagulation Assessment of coag status is

essential before reg anaesthesia .

Epidural analgesia

Early epidural is an ideal form of pain relief in preceelamptic pts.

It helps to control the exaggerated hypertensive response to pain and can improve placental blood flow.

A functioning epidural may safely be etended for C/S.

Anaesthesia for c/s

Regional vs G/A 1 Avoidance of hypertensive

response to laryngoscopy [more in preecclamptics]

2 Blunting of neuro endocrine response to surgery

3 Prevention of transient neonatal depression associated vth G/A.

Spinal vs epidural Advantages 1. quicker and more reliable in on set 2. less potential trauma in the epidural

space. Dis advantages theoretical risk of more abrupt

hypotension in a pt who may be relatively hypovolumic and with a fetus who may be compromosed by palcental insufficiency.

Aternatively CSE used .....giving small dose of L/A in SA and option of utilizing the epidural as necessary.

General anaesthesia

G/A may be necessary Main concerns; 1.mucosal oedema of upper

airway 2.severe hypertensive

responses to laryngoscopy and surgery 3.pts on mgso4 may be very

sensitive to effects of NDMRs Difficult obstetric intubation trolley

ready.

Feotal distress

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DEFINITION

Foetal distress is defined as depletion of oxygen and accumulation of carbon dioxide,leading to a state of hypoxia and acidosis during intra uterine life.

causes

During labor; umblical cord prolapse umblical cord

compression [variable

deceleration] uteroplacental

insufficency [late

deceleration] At delivery; shoulder dystocia

management

Change maternal position Administer supplemental oxygen Maintain/improve maternal

circulation Give a tocolytic for hypertonicity Deliver ......forceps C/S

CLASSIFICATION OF C/S ACCORDING TO URGENCY Catagory 1 .requiring immediate delivery

[a threat to maternal and foetal life]

Catagory 2.requiring urgent delivery [maternal and foetal compromise that is not immediately life threatening] Catagory 3.requiring early delivery [no maternal or foetal compromise] Catagory 4.elective delivery [at a time suited to the women and

maternity staff]

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Thank you