Bystander-initiated conventional vs compression-only cardiopulmonary resuscitation and outcomes after out-of-hospital cardiac arrest due to drowning

Abstract

Background: Great emphasis has been placed on rescue breathing in out-of-hospital cardiac arrest (OHCA) due to drowning. However, there is no evidence about the effect of rescue breathing on neurologically favorable survival after OHCA due to drowning. The aim of this study is to examine the effect of bystander-initiated conventional (with rescue breathing) versus compression-only (without rescue breathing) cardiopulmonary resuscitation (CPR) in OHCA due to drowning.

Methods: This nationwide population-based observational study using prospectively collected government-led registry data included patients with OHCA due to drowning who were transported to an emergency hospital in Japan between 2013 and 2016. The primary outcome was one-month neurologically favorable survival.

Results: The full cohort (n = 5121) comprised 2486 (48.5%) male patients, and the mean age was 72.4 years (standard deviation, 21.6). Of these, 968 (18.9%) received conventional CPR, and 4153 (81.1%) received compression-only CPR. 928 patients receiving conventional CPR were propensity-matched with 928 patients receiving compression-only CPR. In the propensity score-matched cohort, one-month neurologically favorable survival was not significantly different between the two groups (7.5% in the conventional CPR group vs. 6.6% in the compression-only CPR group; risk ratio, 1.15; 95% confidence interval, 0.82-1.60; P = 0.4147). This association was consistent across a variety of subgroup analyses.

Conclusions: Among patients with OHCA due to drowning, there were no differences in one-month neurologically favorable survival between bystander-initiated conventional and compression-only CPR groups, although several important data (e.g., water temperature, submersion duration, or body of water) could not be addressed. Further study is warranted to confirm our findings.

Keywords: Basic life support; Cardiopulmonary resuscitation; Drowning; Epidemiology; Out-of-hospital cardiac arrest.