Werdehausen Robert, Braun Sebastian, Hermanns Henning, Freynhagen Rainer, Lipfert Peter, Stevens Markus F
Department of Anesthesiology, University of Düsseldorf, Düsseldorf, Germany.
Reg Anesth Pain Med. 2007 Jan-Feb;32(1):73-8. doi: 10.1016/j.rapm.2006.07.009.
Skin-temperature increase is a reliable but late indicator of success during regional-anesthesia techniques. The goal of this study is to determine the distribution of skin-temperature changes during different regional techniques. Does skin temperature increase in the whole area innervated by the blocked neural structures or only in certain regions within this area with the capability to react preferentially to sympathetic block (i.e., vessel-rich skin)? Although onset time may vary between different regional-anesthetic techniques, we hypothesized that the distribution of skin warming is equal.
Skin temperature was assessed continuously by infrared thermography in 24 patients who received either combined femoral-nerve and sciatic-nerve block, epidural anesthesia, or spinal anesthesia.
Apart from differences in time of onset, no differential spatial distribution of skin-temperature changes could be detected. The earliest and greatest rise of skin temperature occurred at the great toe (10.6 degrees C +/- 0.4 degrees C), became smaller proximally, and was negligible above the ankles, irrespective of the type and extent of block. Video-thermography revealed that cold blood flows through subcutaneous veins immediately after onset of sympathetic block and initially decreases skin temperature (0.6 degrees C +/- 0.3 degrees C) during onset of spinal anesthesia.
Irrespective of the applied regional-anesthetic technique, skin-temperature changes are more pronounced distally. Thermography prevents false measurements of skin temperature above subcutaneous veins and displays flow of cold blood as the mechanism of initial skin-temperature drop after regional anesthesia. Measurements of skin-temperature increase cannot be used to evaluate the extent of analgesia or sympathetic block.
皮肤温度升高是区域麻醉技术成功的一个可靠但较晚出现的指标。本研究的目的是确定不同区域麻醉技术过程中皮肤温度变化的分布情况。皮肤温度升高是发生在被阻滞神经结构所支配的整个区域，还是仅发生在该区域内某些对交感神经阻滞有优先反应能力的特定区域（即血管丰富的皮肤）？尽管不同区域麻醉技术的起效时间可能有所不同，但我们假设皮肤升温的分布是相同的。
通过红外热成像连续评估24例接受股神经和坐骨神经联合阻滞、硬膜外麻醉或脊髓麻醉患者的皮肤温度。
除起效时间不同外，未检测到皮肤温度变化的差异空间分布。无论阻滞类型和范围如何，最早且最大的皮肤温度升高发生在大脚趾（10.6℃±0.4℃），向近端逐渐变小，在踝关节以上可忽略不计。视频热成像显示，交感神经阻滞后立即有冷血通过皮下静脉流动，并且在脊髓麻醉起效期间最初会使皮肤温度降低（0.6℃±0.3℃）。
无论采用何种区域麻醉技术，皮肤温度变化在远端更为明显。热成像可防止对皮下静脉上方皮肤温度的错误测量，并显示冷血流动是区域麻醉后最初皮肤温度下降的机制。皮肤温度升高的测量不能用于评估镇痛或交感神经阻滞的程度。
