Breakthrough Fever in Cardiac Arrest Patients Without the Use of a Cooling Device

Background: Fever avoidance after cardiac arrest is recommended but cooling devices may not be used even if targeting normothermia. Objectives: We sought to establish the incidence of postarrest fever and association with clinical outcomes depending on whether a cooling device was used. Methods: We conducted a retrospective study of adult cardiac arrest survivors admitted to intensive care units (ICUs) in our health system in 2021. Our primary outcome was discharged alive. Univariate and multivariable statistics were computed, and additional outcomes included cooling device use, Tmax of ≥38°C within 48 h of admission, and Glasgow Coma Scale (GCS) ≥8 at discharge. Results: 364 patients were screened and 194 ultimately analyzed. Seventy-eight (40.2%) were female, median (IQR) age was 63 (54.0–72.8) years old, 96 (49.7%) were provided a cooling device, and 49 (25.3%) reached a temperature ≥38°C within 48 h of admission. Patients without a cooling device more often reached Tmax ≥38°C (37.1% vs. 13.5%, p < 0.001). Greater GCS on day 3 was a consistent independent predictor of being discharged alive and of GCS ≥8 at discharge while failure to use a cooling device was the strongest independent predictor of postarrest fever. Conclusions: Cooling devices were associated with fever prevention but used in patients who ultimately did poorly. Moreso than use of a cooling device, achieving fever avoidance may be more important for prognosis.