Bennett J, Ramachandra V, Webster J, Carli F
Department of Anaesthesia, Northwick Park Hospital, Harrow, Middlesex.
Br J Anaesth. 1994 Aug;73(2):180-3. doi: 10.1093/bja/73.2.180.
We have measured aural canal (core) and skin temperatures, and body heat content in 45 patients undergoing elective hip arthroplasty. They received general anaesthesia which included thiopentone, vecuronium and enflurane and nitrous oxide in oxygen. Patients were allocated randomly to three groups: group 1, control (n = 15), received no intraoperative warming device; group 2 had passive skin surface warming (metallized plastic sheet, Thermolite (n = 15); and group 3 had active skin surface warming (forced heated air, Bair-Hugger) (n = 15). Duration of surgery, fluid administration and the temperature and relative humidity of the operating theatre were similar for the three groups. Core temperature and mean body heat content decreased significantly during surgery in groups 1 and 2 (aural canal temperature 1.5 and 1.0 degrees C, and mean body heat content 287 and 189 kJ, respectively), while in group 3 these variables remained near preoperative values (P = 0.001). Mean skin and hand temperatures decreased in the control group, increased in the active warming group and were unchanged in the passive warming group (P < 0.005), indicating that the forced heated air system was very efficient in providing thermal homeostasis during surgery, while the metallized plastic sheet was able to insulate the skin only from radiant and convective heat losses, without attenuating the reduction in core temperature.
我们测量了45例行择期髋关节置换术患者的耳道（核心）温度、皮肤温度和身体热量含量。他们接受了包括硫喷妥钠、维库溴铵、安氟醚以及氧气和笑气的全身麻醉。患者被随机分为三组：第1组为对照组（n = 15），未使用术中保暖装置；第2组采用被动皮肤表面保暖（金属化塑料片，Thermolite，n = 15）；第3组采用主动皮肤表面保暖（强制热风，Bair-Hugger）（n = 15）。三组患者的手术时间、液体输入量以及手术室的温度和相对湿度相似。第1组和第2组患者在手术期间核心温度和平均身体热量含量显著下降（耳道温度分别下降1.5℃和1.0℃，平均身体热量含量分别下降287 kJ和189 kJ），而第3组这些变量仍接近术前值（P = 0.001）。对照组的平均皮肤温度和手部温度下降，主动保暖组升高，被动保暖组无变化（P < 0.005），这表明强制热风系统在手术期间维持热稳态方面非常有效，而金属化塑料片仅能使皮肤免受辐射和对流热损失，而不会减弱核心温度的降低。
