Hata J Steven, Shelsky Constance R, Hindman Bradley J, Smith Thomas C, Simmons Jonathan S, Todd Michael M
The Division of Critical Care, Department of Anesthesia, University of Iowa Hospitals and Clinics, Iowa City, IA 52242, USA.
Neurocrit Care. 2008;9(1):37-44. doi: 10.1007/s12028-007-9015-1.
Fever after acute brain injury appears to be a detrimental factor, associated with impaired neurological outcomes. This study assessed physiological changes in systemic oxygen consumption (VO2) during cutaneous cooling after severe brain injury.
This prospective, observational, clinical study evaluated ten, critically ill, brain-injured patients requiring mechanical ventilation with a core body temperature of greater or equal to 38 degrees C. Febrile patients failing to defervesce after acetaminophen underwent indirect calorimetry for a 1-hour baseline period followed by a 4 h cooling period. The Arctic Sun(R) Temperature Management System (Medivance) directed core temperature to a goal of 36 degrees C.
The patients had a mean age of 32 years (95% CI 23, 40), Glasgow Coma Scale of 6 (95% CI 5,7), and APACHE 2 score of 19 (95% CI 15, 22), with 8 of 10 patients suffering traumatic brain injuries. The baseline 1-h core temperature was significantly reduced from 38.6 degrees +/- 0.9 to 36.3 degrees +/- 1.2 degrees C (P < 0.0001) over 4 h. Two cohorts were identified based upon the presence or absence of shivering. Within the non-shivering cohort, systemic VO2 was significantly reduced from 415 +/- 123 to 308 +/- 115 ml/min (-27 +/- 18%) (P < 0.05). In contrast, those with shivering showed no significant reduction in VO2, despite significantly decreasing core temperature. The overall percentage change of VCO2 correlated with VO2 (r (2) = 0.91).
Fever reduction in acute brain injury appears to significantly reduce systemic VO2, but is highly dependent on shivering control.
急性脑损伤后发热似乎是一个有害因素，与神经功能预后受损有关。本研究评估了重度脑损伤后皮肤降温期间全身氧耗量（VO2）的生理变化。
这项前瞻性、观察性临床研究评估了10例需要机械通气、核心体温大于或等于38摄氏度的重症脑损伤患者。对服用对乙酰氨基酚后仍未退热的发热患者进行1小时基线期的间接测热法，随后进行4小时的降温期。北极光温度管理系统（Medivance）将核心温度控制在36摄氏度的目标。
患者的平均年龄为32岁（95%可信区间23,40），格拉斯哥昏迷量表评分为6分（95%可信区间5,7），急性生理与慢性健康状况评分系统II（APACHE 2）评分为19分（95%可信区间15,22），10例患者中有8例患有创伤性脑损伤。在4小时内，基线1小时核心温度从38.6摄氏度±0.9显著降至36.3摄氏度±1.2摄氏度（P<0.0001）。根据是否存在寒战确定了两个队列。在无寒战队列中，全身VO2从415±123显著降至308±115毫升/分钟（-27±18%）（P< .05）。相比之下，有寒战的患者尽管核心温度显著下降，但VO2没有显著降低。VCO2的总体百分比变化与VO2相关（r(2)=0.91）。
急性脑损伤时降低发热似乎能显著降低全身VO2，但高度依赖于对寒战的控制。
