Duration of Resuscitation Impacts Favorable Outcomes

Shorter resuscitation times of out-of-hospital cardiac arrest (OHCA) patients have a positive impact on favorable functional outcomes, according to a new study.

Researchers at Michigan State University (East Lansing, MI, USA), the University of Alabama (Birmingham, USA), and other institutions conducted an analysis of a large, multi-center, study involving 11,368 patients (median age 69, 62.6% male), who were resuscitated by emergency medical services (EMS) following OHCA. The primary exposure of the analysis was duration of resuscitation, defined by return of spontaneous circulation (ROSC) or termination of resuscitation. The primary outcome was survival to hospital discharge.

Patients were additionally classified into those who survived with unfavorable outcome, those who had ROSC but did not survive, and those without ROSC. Accrual was plotted as a function of resuscitation duration, and the dynamic probability of favorable outcome at discharge was estimated for the whole cohort and in subgroups. The results revealed that 35.4% of the patient’s achieved ROSC, 10.8% survived to hospital discharge, and 8% survived to hospital discharge with favorable outcome.

The distribution of cardiopulmonary resuscitation (CPR) duration differed by outcome; for CPR duration of up to 37 minutes, 99% of patients with eventual favorable outcome at discharge had achieved ROSC. The probability of favorable outcomes declined over longer resuscitation duration, but subjects with initial shockable cardiac rhythm, witnessed cardiac arrest, and bystander CPR were more likely to survive with favorable outcome after prolonged efforts (30-40 minutes). The study was published on October 19, 2016, in Circulation.

“Adjusting for prehospital and inpatient covariates, resuscitation duration was associated with survival to discharge with eventual favorable outcome,” concluded lead author Joshua Reynolds, MD, of the MSU College of Human Medicine, and colleagues. “Shorter resuscitation duration was associated with likelihood of favorable outcome at hospital discharge. Subjects with favorable case features were more likely to survive prolonged resuscitation up to 47 minutes.”

The 2010 American Heart Association (AHA) guidelines for hands-only CPR call for at least 100 chest compressions per minute for at least two minutes, at a depth of at least two inches in the center of the victim's chest prior to using an AED machine.

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Michigan State University
University of Alabama