In 2015, the American Heart Association and European Resuscitation Council updated the guidelines for cardiopulmonary resuscitation (CPR) and emergency cardiovascular care according to the International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatme

J Thorac Dis 2016;8(8):E791-E793 jtd.amegroups. com In 2015, the American Heart Association and European Resuscitation Council updated the guidelines for cardiopulmonary resuscitation (CPR) and emergency cardiovascular care according to the International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations (1-3). The guidelines recommend administration of amiodarone for sustained ventricular fibrillation (Vf) and ventricular tachycardia (VT) refractory to CPR, defibrillation, and vasopressor in out-of-hospital cardiac arrest. Lidocaine is recommended as an alternative to amiodarone. However, these recommendations remain weak and are based on the two previous randomized controlled trials (RCTs) performed more than 10 years ago. In these trials, compared with both placebo and lidocaine, amiodarone improved the rate of return of spontaneous circulation (ROSC) but not the survival to hospital discharge and neurological outcome (4). However, these studies were not statistically powered to investigate survival and neurological outcome, so the actual efficacy of amiodarone therapy remains undetermined. To address this issue, the Resuscitation Outcomes Consortium performed the RCT called “ALPS”, the results of which were published recently (5). In the trial, amiodarone, lidocaine, or placebo was administered by paramedics for sustained Vf/VT after at least one shock in patients with non-traumatic out-of-hospital cardiac arrest. As per-protocol population, 3,026 patients were evaluated, of whom 974 were assigned to the amiodarone group, 993 to the lidocaine group, and 1,059 to the placebo group. The proportion of survival to hospital discharge, which was the primary outcome of this study, did not significantly differ between the three groups (24.4%, 23.7%, and 21.0% in the amiodarone, lidocaine, and placebo groups, respectively). The neurological function at discharge, which was the secondary outcome, also did not significantly differ. Regarding the ROSC at emergency department arrival, only lidocaine was significantly superior to placebo. What do these results mean? Should we refrain from the use of amiodarone for shock-refractory Vf/VT in cardiac arrest? This study gives us a different message when we focus on the time from collapse to the use of antiarrhythmic drugs. As the authors mentioned in the Discussion section, both amiodarone and lidocaine therapies resulted in significantly better rate of survival to hospital discharge than placebo in bystander-witnessed arrest (27.7%, 27.8%, and 22.7% with amiodarone, lidocaine, and placebo, respectively). Especially in emergency medical services-witnessed cardiac arrest, the rate of survival to discharge was twice higher with amiodarone than with placebo (38.6% vs. 16.7%). This study is the first RCT that showed the efficacy of amiodarone and lidocaine therapies in terms of survival to hospital discharge, although the result was obtained from the subanalysis. The immediate response to cardiac arrest and bystander CPR could be considered as the prerequisite to attaining the efficacy of antiarrhythmic drugs. It may be said that we should use amiodarone or lidocaine at least in witnessed arrest, instead of giving up the use of both drugs. This study is a meaningful study also for lidocaine. Lidocaine has been widely used, but no RCT has shown its efficacy for ROSC in shock-refractory Vf/VT. Although the Commentary