Assessing the efficacy of the new protocol for chest compressions before definitive cardiac arrest in emergency medical service-witnessed adult out-of-hospital cardiac arrests.

AIMS

Japanese emergency medical services (EMS) personnel providing advance life support confirm the absence of a carotid pulse before initiating chest compressions (CCs) in adult out-of-hospital cardiac arrest (OHCA). This study aims to investigate the efficacy of a new protocol facilitating early CCs before definitive cardiac arrest in enhancing the outcomes of OHCA.

METHODS

The 2011 new protocol facilitated EMS to initiate CCs when the carotid pulse was weak and/or <50/min in comatose adult patients with respiratory arrest (apnoea or agonal breathing) and loss of the radial pulse. During 2008-2015, we compared the neurologically favourable 1-year survival rate of EMS-witnessed OHCA and EMS-confirmed out-of-hospital respiratory arrest (OHRA) in adults before (N = 257 and 34, respectively) and after (N = 255 and 54, respectively) the implementation of the new protocol.

RESULTS

After the new protocol, EMS initiated CCs >1.5 min before definitive cardiac arrest in 31% (80/255) and 33% (18/54) of EMS-witnessed OHCA and EMS-confirmed OHRA, respectively. While the new protocol was not significantly associated with survival of EMS-confirmed OHRA, it was significantly associated with survival of EMS-witnessed OHCA: 9.0% and 14.9%, before and after, P by univariate analysis <0.03; adjusted OR (95% CI) by multivariable logistic regression analysis, 2.01 (1.04-3.90). Neither early start of CCs nor the new protocol was associated with the progression to cardiac arrest in 212 cases with impending cardiac arrest.

CONCLUSIONS

A new EMS protocol facilitating early CCs before definitive cardiac arrest was associated with higher survival of EMS-witnessed OHCA.