Change of target temperature from 36 °C to strict fever avoidance only in comatose cardiac arrest survivors - A before and after study

Aim: The guidelines on temperature control for comatose cardiac arrest survivors were recently changed from recommending targeted temperature management (32-36 °C) to fever control (≤37.7 °C). We investigated the effect of implementing a strict fever control strategy on prevalence of fever, protocol adherence, and patient outcome in a Finnish tertiary academic hospital.

Methods: Comatose cardiac arrest survivors treated with either mild device-controlled therapeutic hypothermia (≤36 °C, years 2020-2021) or strict fever control (≤37 °C, year 2022) for the first 36 h were included in this before-after cohort study. Good neurological outcome was defined as a cerebral performance category score of 1-2.

Results: The cohort consisted of 120 patients (≤36 °C group n = 77, ≤37 °C group n = 43). Cardiac arrest characteristics, severity of illness scores, and intensive care management including oxygenation, ventilation, blood pressure management and lactate remained similar between the groups. The median highest temperatures for the 36 h sedation period were 36.3 °C (≤36 °C group) vs. 37.2 °C (≤37 °C group) (p < 0.001). Time of the 36 h sedation period spent >37.7 °C was 0.90% vs. 1.1% (p = 0.496). External cooling devices were used in 90% vs. 44% of the patients (p < 0.001). Good neurological outcome at 30 days was similar between the groups (47% vs. 44%, p = 0.787). In multivariable model the ≤37 °C strategy was not associated with any change in outcome (OR 0.88, 95% CI 0.33-2.3).

Conclusions: The implementation strict fever control strategy was feasible and did not result in increased prevalence of fever, poorer protocol adherence, or worse patient outcomes. Most patients in the fever control group did not require external cooling.