1. What is amniotic fluid embolism?
An acute cardio respiratory collapse within 6 hours after labour, birth or ruptured membranes,
with no identifiable cause, followed by acute coagulopathy in those women who survived the
initial period
Case fatality rate is 19% in UK
2. what is the pathogenesis ?
Theory 1 Breach in barrier between circulation
Tears in lower segment and veins in endocervix
Osmotic gradient created between uterus and maternal circulation
Theory 2 Amniotic fluid debris cause obstruction
Theory 3 Abnormal maternal immunological response
3. explain the pathophysiology of AFE?
Haemodynamic changes
1. Vasospasm
2. Severe PHTN
3. Acute RHF
4. Left side deviation of inter atrial and ventricular septum
5.Reduced preload and systemic hypotension
6. LVF
7. Decreased coronary perfusion and ischaemic injury
8. Cardiogenic shock
Humoral factors
Endothelin causes severe vasoconstriction
Coagulopathy
Consumption coagulopathy II, VII, X
Amniotic fluid contains activated coagulation factors
Induce platelet aggregation
4. what are the risk factors for AFE ?
1. Induction of labour
a. PG – X6
Syntocinon
2. Advanced maternal age
3. Caesarian section – x6
4. Vaginal instrumental delivery – x9
5. Multiple pregnancy
6. Placenta praevia
Insufficient evidence Polyhydramnios
Placental abruption
Cervical laceration
Uterine hyperstimulation
Uterine rupture
5. how do they present ?
Time Prior to birth of baby -53-60%
Shortely after delivery within 30 minutes
Symptoms
Numbness, tingling sensation, agitation, chest pain.
Symptoms prior to collapse -47%
Fetal compromise before maternal symptoms -36%
Cardiac arrest -60-80%
Excessive bleeding
Primarily clinical diagnosis and diagnosis of exclusion
Post mortem -fetal squamus in the maternal pulmonary circulation
Other investigations
FBC Hb-reduced
WBC -raised
Clotting profile PT/APTT -prolonged
Fibrinogen -reduced
TEG -total failure of clot formation
ECG Elevated cardiac enzymes
ST,T changes
CXR Diffuse opacity in lung fields
Immune Complements reduced
6. how do you diagnose AFE ?
Supportive
Maintain oxygenation
Circulatory suport
Correct coagulopathy
Reverse any observable physiological abnormalities
MDT management
Principles
Initial resuscitation
tilt the patient for 15 degree
Airway -intubate early
Breathing -high flow oxygen
Iv access
Rapid infusion of crystalloids
Vasopressors or inotropes
Circulation
Delivery
Coagulopathy
Aggressive correction of coagulopathy- FFP
Cryoprecipitate
Platelets
Factor VIIa
Ensure uterine contraction Uterine massage
Rusch balloon
Oxytocics
20% require hysterectomy
Baby If CPR failed for 4 minutes -deliver the baby in 5 minutes
8. What are the complications of AFE?
Maternal Fetal
Mortality -19% in UK Mortality -67/1000
Permanent neurological injury -7% NICU admission
Ventilation
Major morbidity -17% Encephalopathy
Sepsis Long-term morbidity
Renal failure
Thrombosis
Pulmonary oedema
Hysterectomy -21%
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