Clinical analysis of long-time mild hypothermia in patients with high-grade aneurysmal subarachnoid hemorrhage

Objective To explore the clinical effect of long-term mild hypothermia therapy on high-grade aneurysmal subarachnoid hemorrhage (aSAH). Methods A total of 58 patients with high-grade aSAH were retrospectively analyzed who were treated with long-term mild hypothermia at Department of Neurosurgical Intensive Care Unit (ICU), Xuanwu Hospital, Capital Medical University from March 2015 to January 2017. Among them, 24 cases were treated with microsurgical clipping and 34 with interventional endovascular embolization. Follow-up study was carried out through outpatient clinic visit or telephone with the modified Rankin Scale (mRS) score after hospital discharge. Results In 58 patients, the duration of long-term mild hypothermia therapy was 5-14 days with an average of 7.0±4.4 days. Cardiac arrhythmia occurred in 37 (63.8%) patients, hypotension in 50 (86.2%), deep venous thrombosis in 8 (13.8%), gastrointestinal motility disorder in 54 (93.1%), stress ulcers in 8 (13.8%), pneumonia in 30 (51.7%) and acute respiratory distress syndrome in 4 (6.9%) patients. Cerebral vasospasm was reported in 28 (48.3%) patients, chills in 21 (36.2%), coagulation dysfunction in 17 (29.3%), stress hyperglycemia in 15 (25.9%), hypoalbuminemia in 13 (22.4%), catheter-related infection in 6 (10.3%) and delayed cerebral ischemia in 10 (17.2%) patients. There were 8 (13.8%) cases of death reported during treatment. Univariate analysis showed that high-grade Hunt-Hess grades (Ⅳ and Ⅴ) and cerebral vasospasm were the risk factors for death during treatment of long-term mild hypothermia (all P <0.05). A total of 48 patients were followed up for 3-6 months with an average of 4.3±1.9 months. Among them, 56.5%(26/46) achieved favorable outcome and 43.5% (20/46) reported unfavorable results. Among the patients with poor outcome, 6 died and 14 were moderately or severely disabled. Conclusion Long-term mild hypothermia therapy could improve the prognosis of patients with high-grade aSAH.