The role of induced normothermia therapy in treating abnormal hyperthermia after severe subarachnoid hemorrhage

Considering the aggravating effect of hyperthermia on the outcome after experimental brain insult, it is recommended that body temperature be maintained in a safe normothermic range after acute stroke to prevent secondary brain damage by hyperthermia. Here we retrospectively reviewed our recent experiences with mild hypothermia therapy (MHT) for 12 patients with severe subarachnoid hemorrhage [severe SAH: Hunt & Kosnik grade ≥ 4, Glasgow Coma Scale (GCS≤7)≤] with special reference to the incidence of hyperthermia (> 38.0°C) after rewarming, and emphasize the importance of maintaining body temperature in a normothermic range (36-37 °C: induced normothermia therapy; INT). One patient with moderate SAH underwent only the INT to control postoperative brain swelling. The INT was induced with surface cooling under general anesthesia. Of 12 patients treated with MHT, 5 patients (GCS 3, 4) died on the next day because of primary damage. Among the 7 surviving patients treated with MHT and one patient with moderate SAH but not treated with MHT, a high fever was noted in 5 patients (after rewarming in 4). The initial case, presented before the introduction of INT, died soon because of massive brain swelling. In another 2 cases, the fever was caused by pneumonia or urinary tract infection and was able to be controlled with antibiotics and pyretics. The other patient after MHT and the patient not treated with MHT developed high fevers of unknown origin (probably by vasospasm) and underwent INT. In both patients, body temperature was maintained within the normal range and the final outcome was GR (good recovery) and MD (moderate disability), respectively. The efficacy of INT in preventing secondary brain damage was discussed.