Advanced cardiac life support: lessons from recent trials on how to move forward.

PURPOSE OF REVIEW This review discusses potential reasons why many recent large trials in advanced cardiac life support have failed to demonstrate a difference in outcomes and suggests some points for consideration in planning future trials. RECENT FINDINGS The ARREST trial, a small controlled trial studying the effect of intra-arrest extracorporeal membrane oxygenation (ECMO, or E-CPR) on survival and functional outcome in patients with refractory ventricular fibrillation cardiac arrest, was stopped after 30 patients for benefit. This stands in contrast to several recent trials enrolling up to several thousand patients and finding no difference. Three ways in which the ARREST trial approach differed from that of other recent trials, and how those differences may contribute to the possibility of detecting the benefit of an intervention, are discussed. SUMMARY Refining our ability to select patients with potential to benefit from an intervention, providing those interventions earlier, and tailoring the specifics of an intervention to the individual patient all may be important in design of cardiac arrest trials, as illustrated by the large effect seen in the ARREST trial.