Progress of Brain Hypothermia Treatment for Severe Subarachnoid Hemorrhage-177 Cases Experienced and a Narrative Review.

The benefits of hypothermia for the treatment of subarachnoid hemorrhage (SAH) remain controversial. In 1999, we initiated brain hypothermia treatment (BHT) in the hyperacute phase to mitigate the evolution of early brain injury in patients with World Federation of Neurological Surgeons (WFNS) grade V SAH. In June 2014, we introduced endovascular cooling to maintain normothermia for seven days following the initial BHT period. Immediately after the decision to treat the sources of bleeding, cooling was initiated, with a target temperature of 33-34°C. Bleeding sources were extirpated primarily by clipping with decompressive craniectomy. Patients were rewarmed at a rate of ≤1°C/day after ≥48 hours of surface cooling. After being rewarmed to 36°C, temperatures were controlled with antipyretic (chronologically divided into groups A-C with 47, 46, and 46 patients, respectively) or endovascular (group D, 38 patients) cooling. Overall, 177 patients (median age, 62 [52-68] years; 94 [53.1%] women; onset-to-arrival time, 36 minutes [28-50]) were included. The median Glasgow Coma Scale (GCS) score upon admission was 4 (3-6). Median core body temperature was 36 (35.3-36.6)°C on arrival, 34.6 (34.0-35.3)°C on entering the operating room, 33.8 (33.4-34.3)°C upon starting the microsurgical or interventional radiology procedure, and 33.7 (33.3-34.2)°C upon admission to the intensive care unit. There were no significant differences in age, sex, GCS score, pupillary findings, location of bleeding sources, or treatment methods. There were 69 (39.0%) overall favorable outcomes (modified Rankin Scale score of 0-3) at 6 months and 11 (23.4%), 18 (39.1%), 17 (37.0%), and 23 (60.5%) in groups A-D, respectively ( p = 0.0065). The outcomes of patients with WFNS grade V SAH improved over time. Herein, we report our experience using BHT for severe SAH through a narrative review.