487: IS DROWNING DIFFERENT?...A FOCUSED ANALYSIS OF CARDIAC ARREST OUTCOMES ASSOCIATED WITH DROWNING

Abstract

Introduction: Drowning is the 2nd leading cause of accidental death in children < 19 in the US, accounting for > 1,000 deaths/year. Outcome registries frequently combine drowning arrests with all other asphyxia induced cardiac arrests. A recent report of the PECARN out of hospital cardiac arrests (OHCA) identified drowning/asphyxia as one factor associated with improved survival, but did not evaluate drowning as an etiology separate from other respiratory causes of cardiac arrest. Methods: Retrospective cohort study from fifteen children’s hospital associated with the Pediatric Emergency Care Applied Research Network. Patients between 1 day and 18 years of age with an OHCA, chest compressions > 1 minute, return of spontaneous circulation > 20 minutes, and a reported respiratory etiology for OHCA were evaluated. Respiratory causes of arrests were divided into drowning or non-drowning and associations between these groups were tested using Chi 2, Fishers exact test, and kruskal wallis. Logistic regression was used to evaluate the association between arrest etiology and outcome while controlling for potential confounders. Results: Ninety four OHCA were evaluable: drowning 43 (46%) and respiratory failure without drowning 51 (54%). Patients whose OHCA was due to drowning were older (54 months [27, 139] vs 6 months [2, 49]; p<0.001), less likely African American (8 (22%) vs 23 (50%); p= 0.011), less likely to have a pre-existing medical condition (12 (28%) vs 35 (66%); p<0.001), less likely to be witnessed (9 (21%) vs 26 (50%); p= 0.004), and less likely to have ongoing CPR on ED arrival (16 (38%) vs 35 (70%); p=0.003). Drowning patients had a shorter duration of CPR (24 min [IQR: 3, 43] vs 45 min [IQR: 30, 55]; p= 0.012). There was no difference in prevalence of bystander CPR, or lowest pH or highest lactate in the 6 hours following ROSC. There was a trend towards higher survival to discharge for drowning etiology compared to non-drowning etiology: 22/43 (51%) vs 17/51 (33%); p= 0.08 and favorable neurologic outcome: 16/43 (37%) vs 11/51 (22%); p= 0.09. After controlling for age and witnessed status, patients who had an OHCA due to drowning were more likely to survive to discharge (OR 5.25, 95%CI: 1.8, 15.7; p=0.003). Conclusions: OHCA following drowning represents a unique subset of patients that differ from OHCA caused by other respiratory etiologies. Patients’ with drowning as the etiology of OHCA were more likely to survive to discharge. There was a trend towards more favorable neurologic outcome in patients who had an OHCA due to drowning when compared to other causes of asphyxia. OHCA secondary to drowning is a subgroup of patients that should be separated from other respiratory etiologies of cardiac arrest as these patients may have different risk factors for mortality.