Leben J, Tryba M, Kurz-Müller K, Schregel W
Klinik für Anaesthesiologie, Intensiv- und Schmerztherapie, Universitätsklinik Bergmannsheil Bochum.
Anaesthesist. 1998 Jun;47(6):475-8. doi: 10.1007/s001010050585.
Children are very sensible to the occurrence of intraoperative hypothermia (HT) (core temperature < or = 36.0 degrees C) during general anaesthesia because their regulation capacity is less effective than in adults and due to a large skin-surface area compared with their body mass. We compared the efficacy of different heating devices to prevent HT in children during surgery.
With approval of the local ethics committee 50 children between one and seven years, scheduled for peripheral surgery lasting at least 2 hours were included in this study. Anaesthesia was standardized in all patients. Patients were randomly divided into 5 groups. In group 1, in addition to the usual cotton blankets, room temperature was elevated to 27-28 degrees C. In group 2, room temperature was maintained at 27-28 degrees C, and the patients were additionally wrapped into an aluminum blanket. In group 3, elevated room temperature was combined with a convective heating blanket. Patients in group 4 were warmed with an aluminum blanket, while the room temperature was maintained at 22 degrees C. In group 5, room temperature was maintained at 22 degrees C and patients were warmed with a convective heating device (Tab. 1). Room and core body temperature (tympanon membrane) were continuously measured. ANOVA and Fisher's exact Test (significance level: p < 0.05) were performed for the statistical analysis of the results.
The demographic data of all 5 groups, the infused fluid volume and the anaesthetic technique were similar. There were no significant differences concerning age, height and weight of the pediatric patients (Tab. 2). The core temperature decreased by -1.7 degrees C in group 1. In group 4 core temperature decreased by -1.6 degrees C. Using a convective warming system in normal ambient temperature (group 5) core temperature increased by 0.2 degree C and was as effective in the prevention of HT as group 2. A significant increase in core temperature occurred in group 3 +0.7 degree C (Tab. 3 and Fig. 1).
OR temperature seems to be a critical factor influencing heat loss. Increasing OR temperature and covering with cotton sheets was not effective in preventing the heat loss. Increasing room temperature in combination with aluminum sheets is one alternative to prevent HT. Our study shows that the use of a convective warming device prevents HT during a 2-hour surgery in young children even at a OR temperature of about 22 degrees C. In conclusion, in pediatric patients the use of a convective heating system proved to be an effective alternative to room heating.
儿童在全身麻醉期间对术中体温过低（HT）（核心体温≤36.0摄氏度）的发生非常敏感，因为他们的体温调节能力不如成年人有效，且与体重相比皮肤表面积较大。我们比较了不同加热设备在儿童手术期间预防HT的效果。
经当地伦理委员会批准，本研究纳入了50名1至7岁计划进行至少持续2小时外周手术的儿童。所有患者的麻醉均标准化。患者被随机分为5组。第1组，除了通常的棉被外，室温升高到27 - 28摄氏度。第2组，室温维持在27 - 28摄氏度，患者另外用铝箔毯包裹。第3组，升高的室温与对流加热毯相结合。第4组患者用铝箔毯保暖，而室温维持在22摄氏度。第5组，室温维持在22摄氏度，患者用对流加热设备保暖（表1）。持续测量室温和核心体温（鼓膜）。对结果进行方差分析和费舍尔精确检验（显著性水平：p < 0.05）以进行统计分析。
所有5组的人口统计学数据、输注液体量和麻醉技术相似。儿科患者的年龄、身高和体重无显著差异（表2）。第1组核心体温下降了1.7摄氏度。第4组核心体温下降了1.6摄氏度。在正常环境温度下使用对流升温系统（第5组）核心体温升高了0.2摄氏度，在预防HT方面与第2组一样有效。第3组核心体温显著升高0.7摄氏度（表3和图1）。
手术室温度似乎是影响热量损失的关键因素。提高手术室温度并用床单覆盖在预防热量损失方面无效。将室温升高与铝箔床单相结合是预防HT的一种选择。我们的研究表明，即使在手术室温度约为22摄氏度的情况下，使用对流加热设备也能在幼儿2小时手术期间预防HT。总之，在儿科患者中，使用对流加热系统被证明是一种有效的替代室内加热的方法。
