Dear editor:

We are presenting a case of amniotic fluid embolism with presentation of pulmonary embolism during Cesarean section. A 27-year-old healthy woman was admitted to our hospital for scheduled Cesarean section. Her past medical history was unremarkable without any allergies.

In the operation room, spinal anesthesia was performed smoothly and a male neonate (2180 g, Apgar score: 8 to 9) was delivered. During operation, mother was alert without significant hemodynamic change. However, 2 min later, while delivery of the placenta, she became irritated, confused, and started to yell out. Hypotension (58/36 mmHg) and marked sinus bradycardia (32 beats/min), combined with hypoxia (SpO₂ 70%) was presented. Then bradycardia rhythm turned to pulseless electrical activity. Cardiopulmonary resuscitation (CPR) with chest compression was performed immediately and Epinephrine 0.3 mg was administered intravenously. One minute later, she resumed spontaneous circulation. After trachea intubation, a radial arterial cannula and central venous catheter were set up.

Intra-operative TEE was performed after CPR, with finding of grossly dilatation of main pulmonary artery and right ventricle. An embolus was suspected inside the pulmonary artery. Color flow Doppler examination revealed mild pulmonary valve and tricuspid valve regurgitation (Fig. 1A–C). Pulmonary embolism with acute right heart failure was considered.

Download full-size image

Fig. 1. A. TEE applied in midesophageal ascending aorta short axis view revealed enlarged main pulmonary artery (PA) with a embolus inside the lumen (white arrow) near the bifurcation. (Ao: Aorta). B. Under color Doppler exam, right pulmonary artery (RPA) was partially obstructed by the embolus (white arrow). (Ao: Aorta, PA: pulmonary artery). C. In the midesophageal right ventricular inflow-outflow view, dilated pulmonary artery (PA) with diameter 3.04 cm and right ventricle (RV) with diameter 3.61 cm was noted. Tricuspid valve regurgitation (TR) and pulmonary valve regurgitation (PR) were noted under color Doppler exam. (Ao: Aorta, RA: right atrium, LA: left atrium). D. EXTEM trace (left) shows prolonged clot formation time (CFT), decreased α angle, and decreased maximum clot firmness (MCF), suggesting decreased platelet function or fibrinogen deficiency. FIBTEM trace (right) shows decreased MCF, suggesting fibrinogen deficiency. Black dotted lines represent finding in normal patient

Progressive oozing over surgical field and difficult hemostasis raised the suspicion of AFE related disseminated intravascular coagulation (DIC). Blood withdrawn was sent for ROTEM^® with the initial EXTEM trace showed clotting time: 58 s, clot formation time: 890 s, and clot amplitude at 10 min (A10) after clotting time: 15 mm. The FIBTEM A10: 3 mm was also abnormal. These findings suggested coagulopathy with fibrinogen deficiency (Fig. 1D). According to the ROTEM^®, Cryoprecipitate 30 units were given. PRBC 4 units and FFP 6 units were given thereafter in the operation room. After surgery, she stays in SICU for two days and general ward for another 7 days.

The patient collapsed soon after the delivery of placenta which was 15 min after induction of anesthesia. Anaphylactic shock or spinal anesthesia related sympathetic block were less likely at this point. The rupture of uterus membrane while delivery may lead to the entrance of amniotic tissue into the maternal circulation. Finding of suspicious embolus in pulmonary artery is highly suspected to be amniotic tissue.¹ The severe coagulopathy later correlates to anaphylactic reaction to amniotic fluid. The collapse is assumed to be related to suddenly dropped systemic vessel resistance due to DIC or partially obstructed pulmonary artery by the suspicious embolus which caused acute right heart failure. AFE is therefore the final diagnosis.

In our case, right ventricle and pulmonary artery dilatation with tricuspid and pulmonary regurgitation suggested right heart failure. Besides, pulmonary embolism was confirmed with finding of an echogenic embolus in pulmonary artery near the bifurcation with partial obstruction of the right pulmonary artery. This helps guide the treatment plan to right heart failure by maintaining preload and contractility of right heart. Adequate fluid resuscitation with inotropic agents were given. It also helps exclude more common reasons of cardiogenic shock including myocardial infarction, cardiac tamponade, or other structural heart disease.

PPH may take place after AFE rapidly since the DIC situation consumes the coagulation factors. However, some have questioned standard plasma coagulation tests in the management of acute hemorrhage.² The range of ROTEM^® has been used in peri-partum period as reliable reference.³ROTEM^® guided monitor of coagulation function and treatment in PPH is also reported.^4,5 Early detection of clot firmness with A5 (clot firmness at 5 min after clotting time), A10, and A 15, correlate well with MCF (maximum clot firmness).⁶ Therefore, blood transfusion, in this case, Cryoprecipitate, can be given in time while the standard coagulation profile result usually required an hour. The adequate amount of blood component needed can be guided by following data of ROTEM^® to avoid excessive transfusion.

Conflict of interest

None declared.