Out-of-hospital cardiac arrests in Switzerland: Predictors for emergency department mortality in patients with ROSC or on-going CPR on admission to the emergency department

BACKGROUND: One of the leading causes of death is out-of-hospital cardiac arrest (OHCA) with an in-hospital mortality of about 70%. To identify predictors for the high mortality of OHCA patients and especially for women, that are considered at high risk for in-hospital mortality, we evaluated one specific setting of in-hospital treatment after OHCA: the emergency department (ED). METHODS: Retrospective analysis of consecutive ED admissions with OHCA at the Inselspital Bern, Switzerland from 1(st) June 2012 to 31(th) Mai 2015. Demographic, preclinical and ED medical data were compared for patient groups with return of circulation (ROSC) and on-going resuscitation (CPR) on admission, as well as for subgroups with and without ED mortality. Predictors for ED mortality were investigated using univariate analysis with logistic regression. RESULTS: In 354 patients (228 (64.4%) with ROSC; 126 (35.6%) with on-going CPR) we found an overall ED mortality of 28.5% (5.7% ROSC group; 69.8% on-going CPR group). Female gender (OR 7.053 (CI 95% 2.085; 24.853), p = 0.002) and greater age (OR 1.052 (95% CI 1.006–1.101), p = 0.029) were associated with ED mortality in the ROSC but not in the on-going CPR group. Ventricular fibrillation as initially monitored rhythm (OR 0.126 (95% CI 0.027–0.582), p = 0.008) and shorter CPR duration (OR 1.055 (95% CI 1.024;1.088), p = 0.001) were associated with ED survival in patients with ROSC but not in patients with on-going CPR on admission. In ROSC patients a higher lactate and lower pH were associated with mortality (pH: OR 0.009 (CI95% 0.000;0.420), p = 0.016; lactate: OR 1.183 (95% CI 1.037; 1.349), p = 0.013); similar in on-going CPR patients (pH 0.061 (95% CI 0.007, 0.558), p = 0.013, lactate: 1.146 (95% CI 1.041;1.261), p = 0.005). CONCLUSION: Patients with ROSC who died during ED care were predominantly women and older patients, as well as patients with non-shockable initial heart rhythm and long CPR durations. In patients with on-going CPR on admission, no clinical or demographic predictors for ED mortality were found. Higher lactate and lower pH were predictors in both OHCA groups.