EBioMedicine. 2016 Apr;6:253-7. doi: 10.1016/j.ebiom.2016.02.042. Epub 2016 Mar 2.
INTRODUCTION: The current approach to, cardiopulmonary resuscitation of pregnant women in the third trimester has been to adhere to the "four-minute rule": If pulses have not returned within 4min of the start of resuscitation, perform a cesarean birth so that birth occurs in the next minute. This investigation sought to re-examine the evidence for the four-minute rule. METHODS: A literature review focused on perimortem cesarean birth was performed using the same key words that were used in formulating the "four-minute rule." Maternal and neonatal injury free survival rates as a function of arrest to birth intervals were determined, as well as actual incision to birth intervals. RESULTS: Both maternal and neonatal injury free survival rates diminished steadily as the time interval from maternal arrest to birth increased. There was no evidence for any specific survival threshold at 4min. Skin incision to birth intervals of 1min occurred in only 10% of women. CONCLUSION: Once a decision to deliver is made, care providers should proceed directly to Cesarean birth during maternal cardiac arrest in the third trimester rather than waiting for 4min for restoration of the maternal pulse. Birth within 1min from the start of the incision is uncommon in these circumstances.
The optimal treatment of a severe hemodynamic instability from shock to cardiac arrest in late term pregnant women is subject to ongoing studies. However, there is an increasing evidence that early "separation" between the mother and the foetus may increase the restoration of the hemodynamic status and, in the cardiac arrest setting, it may raise the likelihood of a return of spontaneous circulation (ROSC) in the mother. This treatment, called Perimortem Cesarean Section (PMCS), is now termed as Resuscitative Hysterotomy (RH) to better address the issue of an early Cesarean section (C-section). This strategy is in contrast with the traditional treatment of cardiac arrest characterized by the maintenance of cardiopulmonary resuscitation (CPR) maneuvers without any emergent surgical intervention. We report the case of a prehospital perimortem delivery by Caesarean (C) section of a foetus at 36 weeks of gestation after the mother's traumatic cardiac arrest. Despite the negative outcome of the mother, the choice of performing a RH seems to represent up to date the most appropriate intervention to improve the outcome in both mother and foetus.