Objectives: Mild therapeutic hypothermia after out-of-hospital cardiac arrest is usually achieved either by surface cooling or by core cooling via the patient's bloodstream. We compared modern core (Coolgard) and surface (Arctic Sun) cooling devices with a zero hypothesis of equal cooling, complications, and neurologic outcomes.
Design: Single-center observational study.
Setting: University hospital medical and cardiac intensive care units.
Patients: One hundred sixty-seven consecutive patients comatose after out-of-hospital cardiac arrest of all causes treated with mild therapeutic hypothermia in a 5-yr period.
Interventions: Nonrandomized allocation to core or surface cooling depending on availability and physician preference.
Measurements and Main Results: All out-of-hospital cardiac arrest patients' records were reviewed for relevant data regarding medical history, cardiac arrest event, prehospital care, in-hospital treatment, and complications. Survivor neurologic function was reassessed at follow-up after 6 to 12 months. Baseline patient and arrest episode characteristics were similar in the treatment groups. There was no significant difference in survival with good neurologic function, either to hospital discharge (surface, 34/90, 38%; core, 34/75, 45%; p = .345) or at follow-up (surface, 34/88, 39%; core, 34/75, 45%; p = .387). Time from cardiac arrest to achieving mild therapeutic hypothermia was equal with both devices (surface, 273 min, interquartile range 158–330; core, 270 min, interquartile range 190–360; p = .479). There were significantly more episodes of sustained hyperglycemia among the surface-cooled patients (surface, 64/92, 70%; core, 36/75, 48%; p = .005) and significantly more hypomagnesaemia among core-cooled patients (surface, 16/87, 18%; core, 27/74, 37%; p = .01).
Conclusions: In this study, surface and core cooling of out-of-hospital cardiac arrest patients following the same established postresuscitation treatment protocol resulted in similar survival to hospital discharge and comparable neurologic function at follow-up.
From the Department of Anesthesiology (OT, TD), Institute for Experimental Medical Research (OT), Department of Cardiology (AM), Department of Acute Medicine (DJ), and Surgical Intensive Care Unit (KS), Oslo University Hospital, Oslo; and Department of Mathematics and Natural Sciences (BA), University of Stavanger, Stavanger, Norway.
Supported, in part, by grants from South-Eastern Norway Regional Health Authority, Oslo University Hospital, and Anders Jahres Fund.
The authors have not disclosed any potential conflicts of interest.
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