Rajek A, Lenhardt R, Sessler D I, Grabenwöger M, Kastner J, Mares P, Jantsch U, Gruber E
Department of Cardiothoracic and Vascular Anesthesia, University of Vienna, Austria.
Anesth Analg. 1999 Jun;88(6):1220-5. doi: 10.1097/00000539-199906000-00006.
We measured afterdrop and peripheral tissue temperature distribution in eight patients cooled to approximately 17 degrees C during cardiopulmonary bypass and subsequently rewarmed to 36.5 degrees C. A nasopharyngeal probe evaluated trunk and head temperature and heat content. Peripheral tissue temperature (arm and leg temperature) and heat content were estimated using fourth-order regressions and integration over volume from 30 tissue and skin temperatures. Peripheral tissue temperature decreased to 19.7+/-0.9 degrees C during bypass and subsequently increased to 34.3+/-0.7 degrees C during 104+/-18 min of rewarming. The core-to-peripheral tissue temperature gradient was -5.9+/-0.9 degrees C at the end of cooling and 4.7+/-1.5 degrees C at the end of rewarming. The core-temperature afterdrop was 2.2+/-0.4 degrees C and lasted 89+/-15 min. It was associated with 1.1+/-0.7 degrees C peripheral warming. At the end of cooling, temperatures at the center of the upper and lower thigh were (respectively) 8.0+/-5.2 degrees C and 7.3+/-4.2 degrees C cooler than skin temperature. On completion of rewarming, tissue at the center of the upper and lower thigh were (respectively) 7.0+/-2.2 degrees C and 6.4+/-2.3 degrees C warmer than the skin. When estimated systemic heat loss was included in the calculation, redistribution accounted for 73% of the afterdrop, which is similar to the contribution observed previously in nonsurgical volunteers.
Temperature afterdrop after bypass at 17 degrees C was 2.2+/-0.4 degrees C, with approximately 73% of the decrease in core temperature resulting from core-to-peripheral redistribution of body heat. Cooling and rewarming were associated with large radial tissue temperature gradients in the thigh.
我们测量了8例在体外循环期间被冷却至约17℃并随后复温至36.5℃的患者的体温后降及外周组织温度分布。用鼻咽探头评估躯干和头部温度及热量含量。外周组织温度（手臂和腿部温度）及热量含量通过对30个组织和皮肤温度进行四阶回归及体积积分来估算。在体外循环期间外周组织温度降至19.7±0.9℃，随后在104±18分钟的复温过程中升至34.3±0.7℃。冷却结束时核心与外周组织温度梯度为-5.9±0.9℃，复温结束时为4.7±1.5℃。核心体温后降为2.2±0.4℃，持续89±15分钟。它与外周升温1.1±0.7℃相关。冷却结束时，大腿上部和下部中心的温度分别比皮肤温度低8.0±5.2℃和7.3±4.2℃。复温完成时，大腿上部和下部中心的组织分别比皮肤温度高7.0±2.2℃和6.4±2.3℃。当计算中纳入估计的全身热损失时，再分布占体温后降量的73%，这与先前在非手术志愿者中观察到的贡献相似。
17℃体外循环后的体温后降为2.2±0.4℃，核心温度下降约73%是由于体热从核心到外周的再分布所致。冷却和复温与大腿部较大的径向组织温度梯度相关。
