Increased protocol adherence and safety during controlled normothermia as compared to hypothermia after cardiac arrest

Abstract

Purpose: This study aims to compare protocol adherence, neurological outcome and adverse effects associated with a controlled hypothermia versus a controlled normothermia protocol in patients successfully resuscitated after cardiac arrest.

Methods: In this retrospective single-center study in a university intensive care unit in Switzerland, post-cardiac arrest patients were compared before and after a protocol change from targeted temperature management at 33 °C (TTM-33) to 36 °C (TTM-36) using an intravascular cooling device. Protocol adherence was assessed as the primary outcome. Secondary outcomes were in-hospital mortality, neurological outcome and adverse effects.

Results: 373 patients after cardiac arrest were screened, of whom a total of 133 patients were included. Protocol adherence was lower in the TTM-33 group (47% vs 87% of patients, p < 0.01). In-hospital mortality (59% vs 45%, p = 0.15) and neurological outcome (modified Rankin Score < 4 in 33% vs 39% and CPC-Score < 3 in 33% vs 39% of patients, p = 0.60 and 0.97) were similar. Overall incidence of adverse effects was comparable, with bradycardic arrhythmias occurring more frequently in the TTM-33 group.

Conclusion: Protocol adherence was higher in the TTM-36 group. In-hospital mortality and neurological outcome were similar, while bradycardic arrhythmias were encountered more often in TTM-33.

Keywords: Cardiac arrest; Hypothermia; Neurological outcome; Resuscitation; Temperature.