Clifton G L, Miller E R, Choi S C, Levin H S, McCauley S, Smith K R, Muizelaar J P, Wagner F C, Marion D W, Luerssen T G, Chesnut R M, Schwartz M
Vivian L Smith Center for Neurologic Research, Department of Neurosurgery, University of Texas-Houston Medical School, 77030, USA.
N Engl J Med. 2001 Feb 22;344(8):556-63. doi: 10.1056/NEJM200102223440803.
Induction of hypothermia in patients with brain injury was shown to improve outcomes in small clinical studies, but the results were not definitive. To study this issue, we conducted a multicenter trial comparing the effects of hypothermia with those of normothermia in patients with acute brain injury.
The study subjects were 392 patients 16 to 65 years of age with coma after sustaining closed head injuries who were randomly assigned to be treated with hypothermia (body temperature, 33 degrees C), which was initiated within 6 hours after injury and maintained for 48 hours by means of surface cooling, or normothermia. All patients otherwise received standard treatment. The primary outcome measure was functional status six months after the injury.
The mean age of the patients and the type and severity of injury in the two treatment groups were similar. The mean (+/-SD) time from injury to randomization was 4.3+/-1.1 hours in the hypothermia group and 4.1+/-1.2 hours in the normothermia group, and the mean time from injury to the achievement of the target temperature of 33 degrees C in the hypothermia group was 8.4+/-3.0 hours. The outcome was poor (defined as severe disability, a vegetative state, or death) in 57 percent of the patients in both groups. Mortality was 28 percent in the hypothermia group and 27 percent in the normothermia group (P=0.79). The patients in the hypothermia group had more hospital days with complications than the patients in the normothermia group. Fewer patients in the hypothermia group had high intracranial pressure than in the normothermia group.
Treatment with hypothermia, with the body temperature reaching 33 degrees C within eight hours after injury, is not effective in improving outcomes in patients with severe brain injury.
在小型临床研究中，对脑损伤患者进行低温诱导显示可改善预后，但结果并不确定。为研究此问题，我们进行了一项多中心试验，比较低温与正常体温对急性脑损伤患者的影响。
研究对象为392例年龄在16至65岁之间、因闭合性颅脑损伤后昏迷的患者，这些患者被随机分配接受低温治疗（体温33摄氏度），于受伤后6小时内开始，并通过体表降温维持48小时，或接受正常体温治疗。所有患者均接受标准治疗。主要结局指标为受伤后6个月的功能状态。
两个治疗组患者的平均年龄以及损伤类型和严重程度相似。低温治疗组从受伤到随机分组的平均（±标准差）时间为4.3±1.1小时，正常体温治疗组为4.1±1.2小时，低温治疗组从受伤到达到33摄氏度目标体温的平均时间为8.4±3.0小时。两组中57%的患者预后较差（定义为严重残疾、植物状态或死亡）。低温治疗组的死亡率为28%，正常体温治疗组为27%（P = ０.79）。低温治疗组患者住院期间出现并发症的天数多于正常体温治疗组。低温治疗组颅内压升高的患者少于正常体温治疗组。
受伤后8小时内体温降至33摄氏度的低温治疗对改善重度脑损伤患者的预后无效。
