Russ W, Sticher J, Scheld H, Hempelmann G
Department of Anesthesiology and Intensive Care Medicine, Justus Liebig-University of Giessen, Federal Republic of Germany.
Br J Anaesth. 1987 Dec;59(12):1484-91. doi: 10.1093/bja/59.12.1484.
Somatosensory evoked responses after median nerve stimulation were recorded in 21 patients during hypothermic cardiopulmonary bypass. During hypothermia a significant linear correlation (P less than 0.001) was found between evoked potential latency and temperature. Correlation was best for tympanic membrane temperature during cooling and for perfusate temperature (arterial, venous) during rewarming. The increase in latency was more pronounced for middle latency components (N2, N3) and for the early cortical N1 than for the cervical N0 and central conduction time. In all patients N1 was detectable at 26 degrees C, with slightly reduced amplitude. In the rewarming period the changes occurred in the reverse order and pre-bypass values were achieved at normothermia. The slopes of the regression lines were different during cooling and rewarming, when latencies were related to patient (tympanic, nasopharyngeal, rectal) temperature, but identical when arterial or venous blood temperature was used as the reference. No correlation was found between latency and perfusion pressure. We conclude that sophisticated temperature measurement is required to aid the interpretation of evoked responses used during hypothermia.
在21例患者低温体外循环期间记录了正中神经刺激后的体感诱发电位。在低温期间，诱发电位潜伏期与温度之间存在显著的线性相关性（P小于0.001）。降温期间，鼓膜温度与复温期间灌注液温度（动脉、静脉）的相关性最佳。中潜伏期成分（N2、N3）和早期皮质N1潜伏期的增加比颈段N0和中枢传导时间更为明显。所有患者在26℃时均可检测到N1，但其波幅略有降低。在复温期，变化顺序相反，体温正常时达到旁路前值。当潜伏期与患者（鼓膜、鼻咽、直肠）温度相关时，降温期和复温期回归线的斜率不同，但以动脉或静脉血温度为参考时斜率相同。未发现潜伏期与灌注压力之间存在相关性。我们得出结论，需要精确的温度测量来辅助解释低温期间使用的诱发电位。
