Time-dependent effectiveness of chest compression-only and conventional cardiopulmonary resuscitation for out-of-hospital cardiac arrest of cardiac origin

BackgroundLittle is known about the effect of the type of bystander-initiated cardiopulmonary resuscitation (CPR) for prolonged out-of-hospital cardiac arrest (OHCA).ObjectivesTo evaluate the time-dependent effectiveness of chest compression-only and conventional CPR with rescue breathing for witnessed adult OHCA of cardiac origin.MethodsA nationwide, prospective, population-based, observational study of the whole population of Japan included consecutive OHCA patients with emergency responder resuscitation attempts from 1 January 2005 to 31 December 2007. Multiple logistic regression analysis was performed to assess the contribution of the bystander-initiated CPR technique to favourable neurological outcomes.ResultsAmong 55 014 bystander-witnessed OHCA of cardiac origin, 12 165 (22.1%) received chest compression-only CPR and 10 851 (19.7%) received conventional CPR. For short-duration OHCA (0-15 min after collapse), compression-only CPR had a higher rate of survival with favourable neurological outcome than no CPR (6.4% vs. 3.8%; adjusted odds ratio (OR), 1.55; 95% confidence interval (CI), 1.38-1.74), and conventional CPR showed similar effectiveness (7.1% vs. 3.8%; adjusted OR, 1.78; 95% CI, 1.58-2.01). For the long-duration arrests (>15 min), conventional CPR showed a significantly higher rate of survival with favourable neurological outcome than both no CPR (2.0% vs. 0.7%; adjusted OR, 1.93; 95% CI, 1.27-2.93) and compression-only CPR (2.0% vs. 1.3%; adjusted OR, 1.56; 95% CI, 1.02-2.44).ConclusionsFor prolonged OHCA of cardiac origin, conventional CPR with rescue breathing provided incremental benefit compared with either no CPR or compression-only CPR, but the absolute survival was low regardless of type of CPR.