title: Bystander CPR is associated with improved neurologically favourable survival in cardiac arrest following drowning.
abstract: Cardiac arrest associated with drowning is a major public health concern with limited research available on outcome. This investigation aims to define the population at risk, and identify factors associated with neurologically favourable survival.
  
  
  
  The Cardiac Arrest Registry for Enhanced Survival (CARES) database was queried for patients who had suffered cardiac arrest following drowning between January 1, 2013 and December 31, 2015. The primary outcomes of interest were for favourable or unfavourable neurological outcome at hospital discharge, as defined by Cerebral Performance Category (CPC).
  
  
  
  A total of 919 drowning patients were identified. Neurological outcome data was available in 908 patients. Neurologically favourable survival was significantly associated with bystander CPR (Odds Ratio (OR)=2.94; 95% Confidence Interval (CI) 1.86-4.64; p<0.001), witnessed drowning (OR=2.6; 95% CI 1.69-4.01; p<0.001) and younger age (OR=0.97, 95% CI 0.96-0.98; p<0.001). Public location of drowning (OR=1.17; 95% CI 0.77-1.79; p=0.47), male gender (OR=0.9, 95% CI 0.57-1.43; p=0.66), and shockable rhythm (OR=1.54; 95% CI 0.76-3.12; p=0.23), were not associated with favourable neurological survival. AED application prior to EMS was associated with a decreased likelihood of favourable neurological outcome (OR=0.38; 95% CI 0.28-0.66; p<0.001). In multivariate analysis, bystander CPR (adjusted OR 3.02, 95% CI 1.85-4.92, p<0.001), witnessed drowning (adjusted OR 3.27, 95% CI 2.0-5.36, p<0.001) and younger age (adjusted OR 0.97, 95% CI 0.96-0.98, p<0.001) remained associated with neurologically favourable survival.
  
  
  
  Neurologically favourable survival after drowning remains low but is improved by bystander CPR. Shockable rhythms were uncommon and not associated with improved outcomes.
authors.affiliation: Division of Trauma Anesthesiology, Keck School of Medicine of the University of Southern California, 1520 San Pablo Street, Suite 3451, Los Angeles, CA 90033, United States. Electronic address: Joshua.Tobin@med.usc.edu.
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Tobin
authors.affiliation: Indiana University School of Public Health-Bloomington, 1025 E 7th St., Bloomington, IN 47405, United States.
authors.forename: William D
authors.initials: WD
authors.lastname: Ramos
authors.affiliation: Indiana University School of Public Health-Bloomington, 1025 E 7th St., Bloomington, IN 47405, United States.
authors.forename: Yongjia
authors.initials: Y
authors.lastname: Pu
authors.affiliation: Florida State University, College of Medicine, 1115 W Call St., Tallahassee, FL 32304, United States.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Wernicki
authors.affiliation: University of Washington School of Medicine, MB.7.520 - Emergency Medicine, 4800 Sand Point Way NE, Seattle, WA 98105, United States.
authors.forename: Linda
authors.initials: L
authors.lastname: Quan
authors.affiliation: Perelman School of Medicine at the University of Pennsylvania, 3401 Civic Center Blvd., Philadelphia, PA 19104-4399, United States.
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Rossano
mesh_terms: D000328:Adult; D000367:Age Factors; D016887:Cardiopulmonary Resuscitation / Q000379:methods* / Q000706:statistics & numerical data; D004332:Drowning / Q000401:mortality*; D005260:Female; D006801:Humans; D008297:Male; D016017:Odds Ratio; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality* / Q000628:therapy*; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
keywords: Cardiopulmonary arrest; Cardiopulmonary resuscitation and emergency cardiac care; Drowning; Mortality/Survival; Quality and outcomes