Abstract 171: Effect of Shock Delivery After Conversion to Shockable Arrest From Out-of-Hospital Non-shockable Cardiac Arrest
Background: The 2005 guidelines for cardiopulmonary resuscitation (CPR) with electrical therapy recommended a single shock plus an immediate 2 minutes of CPR instead of 3-shock sequences recommended in the 2000 guidelines. The 2010 guidelines have stressed that it is necessary to improve CPR quality. Each set of guidelines recommended a timely shock when non-shockable patients were found to be in shockable rhythm. Few data are available concerning this electrical therapy.
METHODS: From the data of the All-Japan Utstein Registry, a prospective, nationwide, population-based registry of out-of-hospital cardiac arrest (OHCA), we included adult patients who had OHCA due to cardiac etiology, in whom non-shockable arrest were recorded as an initial rhythm, and who received shock after conversion from non-shockable arrest to shockable arrest by emergency medical service (EMS) personnel. Study patients were divided into three groups based on the different guidelines; 3-shock protocol of the 2000 guidelines, single shock plus an immediate 2 minutes of CPR (1-shock protocol) of the 2005 guidelines, and 1-shock protocol with improved CPR quality of the 2010 guidelines. The primary endpoint was favorable neurological outcome at 30 days after OHCA.
RESULTS: Of the patients with non-shockable arrest, 4,138 met the inclusion criteria. The three groups had similar 30-day favorable neurological outcome (2.2% in the 2000G group, 3.4% in the 2005G group, and 3.2% in the 2010G group, p=0.144) in the whole cohort. In the subgroup of cases in which biphasic defibrillators were used, the 2010G group had a significantly higher 30-day favorable neurological outcome than the other groups (1.2% in the 2000G group, 2.9% in the 2005G group, and 3.3% in the 2010G group, p=0.014). Adjusted odds ratios for favorable neurological outcome were 2.74 (95% CI, 1.31 to 5.73) in the 2010G group and 2.21 (95% CI, 1.02 to 4.73) in the 2005G group (reference; the 2000G group). However, no significant differences were seen in the subgroup in which monophasic defibrillators were used.
CONCLUSION: In the cases in which biphasic defibrillators were used, the single-shock protocol of the 2005 and 2010 guidelines were superior to the 3-shock protocol of the 2000 guidelines, in terms of neurological benefits.
- © 2013 by American Heart Association, Inc.