Surface Temperature Control After Cardiac Arrest in the Emergency Department Without Feedback-Controlled Devices: An Observational Single-Centre Cohort Study of Routine Care

Background/Objectives: Guidelines recommend active fever prevention after cardiac arrest, yet many emergency departments (EDs) lack feedback-controlled temperature-management devices. We describe what simple surface methods achieved in one ED. Methods: Observational cohort of 123 comatose adults with return of spontaneous circulation treated with routine care in a university ED (2017–2020; records to March 2019 analysed retrospectively, later documentation collected prospectively). Technique and length of the management period (12 h or 24 h) were chosen by the treating physician without a written protocol: ice packs (n = 51), ice packs plus a forced-air blanket at its lowest heated setting (32 °C; n = 45), a thin sheet only (n = 21), forced air alone (n = 4) or a circulating-water device (n = 2). Trajectories were compared in a mixed-effects model; the primary endpoint, revised post hoc from the original target of ≤36.0 °C, was fever (≥37.7 °C) after cessation. Results: Ice packs plus forced air gave lower temperatures than ice packs alone from 4 h (adjusted difference −0.68 °C, 95% CI −0.95 to −0.41) to 24 h (−0.44 °C), but overshot below 35.0 °C more often (34/45 vs. 9/51). Fever after cessation was more frequent after physician-selected 12 h than 24 h periods (23/33 vs. 6/90) and in the thin-sheet group (20/21). All 21 thin-sheet patients died; baseline differences suggest allocation by prognosis, and mortality was not analysed causally. Conclusions: Ice packs with or without forced air kept most patients below the fever threshold for up to 36 h; the combination cooled more, which did not mean better control. Safety could not be assessed, and randomised evaluation is needed.