Successful Use of Intra-Aortic Balloon Pump in an Amniotic Embolism Case

Disclosures: Dr. Gallegos, Dr. Clarke, Ms. Bashor, and Dr. Abbottsmith report no conflicts of interest regarding the content herein.

Amniotic fluid embolism is a rare and life-threatening complication in pregnancy. Incidence studies range from 1 in 15,200 deliveries in North America to 1 in 53,800 deliveries in Europe, and the reported most maternal fatality rates have declined from 85% in 1979 to a range of 13.3% to 44% in the most recent studies.¹  

The reason for the large range between countries is unknown, and thought to potentially be related to reporting discrepancies. While AFE should not be considered uniformly lethal, treatment is largely based on supportive measures to help maintain oxygenation, cardiac output and blood pressure, and the correction of coagulopathy.

We report the case of a patient with complete circulatory shutdown due to AFE, who was successfully revived with the use of intra-aortic balloon pump (IABP). 

Case report

A 28 year-old Caucasian female (5 pregnancies, 3 live births [G5P3]) with a previous history of still birth at 28 weeks and a previous diagnosis of syphilis, presented in active labor with a twin pregnancy. She was at 31 weeks gestation and required a cesarean section due to breech malposition of the fetuses. The intraoperative case was not complicated by excessive blood loss and Twin A was delivered without incident. However, prior to delivery of Twin B, a large amount of amniotic fluid was noted on breach of the amniotic sac. The patient then underwent circulatory shutdown and decompensated into cardiopulmonary arrest following delivery of Twin B.

Ventricular tachycardia/ventricular fibrillation, pulseless electrical activity (PEA) and multiple resuscitation pathways were pursued, including multiple rounds of epinephrine, sodium bicarbonate, calcium chloride, amiodarone administrations and multiple defibrillations. Two electrocardiograms (EKGs) were performed, which showed marked ST segment elevation in the inferior leads with reciprocal depression in leads 1 and L. 

A Bakri balloon uterine tamponade device was placed to stop the postpartum hemorrhage, the uterus was replaced, surgically closed, and the incision site stapled during code. A transesophageal echocardiogram (TEE) showed evidence of left ventricular failure, with evidence of ischemia noted on electrocardiogram. 

An intra-aortic balloon pump (IABP, Maquet, Figure 1) was placed via the right femoral artery with TEE guidance. Once the IABP was advanced successfully, the device was turned on and the patient’s hemodynamics improved. When a tenuous pulse was regained, the patient was taken to the cath lab to ensure that she was not experiencing myocardial infarction or spontaneous coronary dissection.

The patient then underwent right and left heart catheterization, which showed normal coronary arteries, an ejection fraction of 40%, no mitral valve regurgitation, and no aortic stenosis with left ventricular systolic dysfunction with segmental contraction abnormalities. With myocardial infarction and acute coronary artery dissection ruled out, the cause of the cardiac arrest remained unexplained. The diagnosis was considered to be amniotic fluid embolism (AFE), as there were no other obvious causes to cardiopulmonary arrest.

As the patient demonstrated signs and symptoms of intra-abdominal bleeding, the patient was taken from the cath lab to the OR for a full abdominal hysterectomy. She remained mechanically ventilated, sedated, and on neuromuscular blockade. Hypothermia protocol was initiated for suspected anoxic brain injury status post cardiac arrest. Her hospital course was complicated by acute respiratory distress syndrome, disseminated intravascular coagulation, and sepsis.

The patient was on an IABP for three days, and was weaned off as she demonstrated decreased need for vasopressors. The patient tolerated removal of the IABP and maintained hemodynamic stability as measured by Swan-Ganz catheter reading. The patient progressed through her complicated hospital course and was admitted to the acute rehab unit, where she rehabilitated to minimal assists with activities of daily living. 

Discussion

AFE is a rare event, and treatment is generally limited to oxygen, medications, and blood transfusions. Risk factors for AFE remain poorly understood. Population-based retrospective cohort studies are the only data available, limiting the ability to make inferences about causality due to lack of information about temporal relationships. In any case, cesarean delivery was the only risk factor significantly associated with AFE present in this case.¹ 

While use of IABP for AFE is not common, it is a well-known and accepted treatment for acute cardiogenic shock. This patient received various rounds of resuscitation with multiple pathways pursued, without success. While multiple rounds of cardiopulmonary resuscitation can cause risk of anoxic brain injury, this patient was spared from any lasting brain damage. The patient demonstrated signs of disseminated intravascular coagulation (DIC) prior to IABP placement and while IABP can cause some thrombocytopenia, this patient did not experience an increase in bleeding following IABP placement. No other bleeding, trauma or site infections were documented on this patient.

In this case, the decision to transfer the patient to the cath lab and use an IABP is very likely what saved her life, and may be a good alternative for other patients once other potentially catastrophic issues, such as spontaneous coronary artery dissection, have been ruled out. A strong, multidisciplinary team able to adapt to the emergency at hand was integral to the success of this case.

Reference

1. Conde-Agudelo A, Romero R. Amniotic fluid embolism: an evidence based review. Am J Obstet Gynecol. 2009 Nov; 201(5): 445.e1–445.13.