Characteristics and outcome of patients with hypothermic out-of-hospital cardiac arrest: Experience from a European trauma center.

Background: Aim of the study was to investigate patient characteristics, survival rates and neurological outcome among hypothermic patients with out-of-hospital cardiac arrest (OHCA) admitted to a trauma center.

Methods: A review of patients with OHCA and a core temperature ≤32°C admitted to a trauma center between 2004 and 2016.

Results: Ninety-six patients (mean temperature 25.8°C±3.9°C) were entered in the study, 37 (39%) of them after avalanche burial. 47% showed return of spontaneous circulation (ROSC) prior to hospital admission. Survival with Glasgow-Pittsburgh Cerebral Performance Category (CPC) scale 1 or 2 was achieved in 25% of all patients and was higher in non-avalanche than in avalanche cases (35.6% vs 8.1%, p=0.002). Witnessed cardiac arrest was the most powerful predictor of favourable neurological outcome (RR: 10.8; 95% Confidence Interval: 3.2-37.1; Wald: 14.3; p<0.001), whereas ROSC prior to admission and body core temperature were not associated with survival with favourable neurological outcome. Cerebral CT scan pathology within 12h of admission increased the risk for unfavourable neurological outcome 11.7 fold (RR: 11.7; 95% CI: 3.1-47.5; p<0.001). Favourable neurological outcome was associated lower S 100-binding protein (0.69±0.5μg/l vs 5.8±4.9μg/l, p 0.002) and neuron-specific enolase (34.7±14.2μg/l vs 88.4±42.7μg/l, p 0.004) concentrations on intensive care unit (ICU) admission.

Conclusions: Survival with favourable neurological outcome was found in about a third of all hypothermic non-avalanche patients with OHCA admitted to a trauma center.