Amniotic Fluid Embolism

Amniotic fluid embolism (AFE) is a rare, unpredictable and potentially catastrophic obstetric emergency characterized by sudden maternal cardiovascular and respiratory compromise, frequently accompanied by severe coagulopathy. A patient who was coping with contractions a minute ago becomes breathless, grey and frightened, and then the monitor changes. AFE typically occurs during labour, delivery or shortly after birth. In one national registry, 70% of cases occurred during labour, 11% after a vaginal birth and 19% during a caesarean birth. The reported incidence is about two to six cases per 100,000 births, and the case fatality rate ranges from about 20% to 40% or more in classic cases. Many units meet only one or two cases in a decade, so most nurses will face their first one without having seen it before. That is why the response has to be a practised habit rather than a memory of a rare disease. Despite its name, AFE is not simply a mechanical obstruction caused by amniotic fluid entering the pulmonary circulation. Current understanding suggests a complex maternal inflammatory and cardiovascular response to fetal or amniotic...