Managing Maternal Cardiac Arrest in Canada

Abstract

Fortunately, maternal mortality is a rare occurrence in the developed world and even more uncommon when the mortality is due to maternal cardiac arrest – the estimated rate is 1:20,000-1:30,000 pregnancies. When maternal cardiac arrest occurs, the lives of both the parturient and fetus are at risk. Consequently, there is a very brief window of opportunity for return of hemodynamic stability before the risk of permanent harm to the mother and fetus begins. Despite parturients being younger than the typical patient experiencing cardiac arrest, there are a variety of complex reasons why survival is reported at less than 10%. Substandard care, poor resuscitation attempts, and lack of compliance with accepted resuscitation algorithms have been common themes in the Centre for Maternal and Child Enquiries (CMACE) triennial reports out of the United Kingdom (UK). Importantly, commentary and management strategies have followed the publication of each report, and progress has been made over time to improve how providers manage these rare events. In 2000, the American Heart Association (AHA) clearly spelled out the rationale to advocate proceeding with an emergent Cesarean delivery after four minutes of maternal cardiac arrest. In 2010, the AHA developed a separate maternal cardiac arrest algorithm. While it is true that the evidence – first put forth in 1986 – is from case series and there will always be individual cases where a longer period of lack of blood flow to the uterus still results in a live intact neonate, it has been reported that a fetus more than 24-25 weeks’ gestation experiencing more than ten minutes of absent blood flow will generally experience neurological (and other) deficits. More importantly, evacuation of the gravid uterus makes successful maternal resuscitation much more likely regardless of gestational age. In a resuscitation scenario during which the application of good-quality chest compressions produces no palpable maternal pulse, uterine evacuation should be expedited. The release of aortocaval compression and autotransfusion effects may potentially facilitate attempts at maternal resuscitation. In this issue of the Journal, Baghirzada and Balki describe the experience with maternal cardiac arrest in their Canadian institution over a 12-year period. One of their conclusions is that the four-minute rule need not be applied too rigorously, as they provide evidence for intact neonatal survival up to 14 min after loss of maternal circulation. These observations are consistent with other case reports. The authors not only identified poor documentation for each of the five cases, but they also reported the difficulty in organizing and mobilizing the team to initiate the emergent Cesarean delivery within four minutes post-arrest. Rather than conclude that perhaps it is acceptable to delay the decision and start of surgery, there are other lessons to be learned; for example, all practitioners practicing in a hospital providing obstetrical services need to carry out a critical appraisal of their overall readiness to manage maternal cardiac arrest. If there are no clear, concise, and precise guidelines, it has been well documented that the entire team will be challenged to proceed in a protocol during management of cardiac arrest in any patient. This is recognized in the latest R. Preston, MD (&) Department of Anesthesiology, Pharmacology & Therapeutics, Faculty of Medicine, University of British Columbia, Rm 3300 JPPN, 910 W 10th Avenue, Vancouver, BC V5Z 1M9, Canada e-mail: roanne.preston@ubc.ca