Amniotic fluid embolism with right heart masses presenting as cardiac arrest during labour

A healthy 34-year-old, gravida 5 para 2 woman presented to the antenatal clinic for routine assessment at 29weeks gestation. She reported a two-day history of lower abdominal cramping pain with associated minor vaginal bleeding, and was found to be in active labour. Ultrasound demonstrated a singleton fetus in transverse lie, and internal examination revealed a fully dilated cervix with bulging membranes. A decision was made to perform an emergency lower segment caesarean section (LSCS). The patient underwent a routine spinal anaesthetic achieving a satisfactory neuraxial block prior to incision. Upon opening of the membranes, the patient became confused, had seizure-like activity, lost consciousness and became profoundly cyanosed. Bradycardia was rapidly followed by complete loss of cardiac output. Advanced life support was commenced, with a live male infant delivered immediately prior to commencement of chest compressions. The uterus was exteriorised and compressed during cardiopulmonary resuscitation. Tracheal intubation was performed, and femoral venous and arterial sheaths were placed in preparation for extracorporeal life support (ECLS). Return of spontaneous circulation (ROSC) was obtained after 17min of advanced life support and blood pressure was supported by an epinephrine (adrenaline) infusion. The uterus was internally repositioned. Uterine atony and bleeding were treated with intravenous oxytocin and intra-uterine balloon tamponade. Haemostasis was difficult to achieve, with clinically apparent coagulopathy. Pathology results demonstrated disseminated intravascular coagulopathy (DIC); International Normalized Ratio 7.8, prothrombin time 65.4 s, activated partial thromboplastin time >200 s, platelets 32 10/L, fibrinogen 0.14 g/L; as well as a lactic acidosis: pH7.1, lactate 6.3mmol/L. The patient received 2 units of packed red blood cells, 2 units of pooled platelets, 2 units of fresh frozen plasma, 26 units of whole blood cryoprecipitate, tranexamic acid 1 g, and calcium chloride 10mmol. A presumptive diagnosis of AFE was made. Transoesophageal echocardiography (TOE) performed 18min post ROSC revealed extensive echodense masses within the right heart (Figures 1 and 2) and inferior vena cava. The masses in the right atrium and the right ventricle were large, highly mobile and heterogeneous, with a gelatinous appearance. No patent foramen ovale was seen. The patient was reviewed intraoperatively by specialists from cardiothoracic surgery, interventional radiology, and intensive care. Bedside bilateral lower limb ultrasonography did not demonstrate deep vein thrombosis. Once sustained haemodynamic improvement was obtained, the patient was transferred to the intensive care unit (ICU) for ongoing management. After 3.5 h, there was only moderate output from the surgical drains and biochemical and coagulation parameters were improving. Formal Doppler sonography confirmed the absence of lower limb thrombi. Twelve hours later, the patient no longer required inotropic or vasopressor support. Transthoracic echocardiography demonstrated complete resolution of the intracardiac masses, with normal biventricular size and