Watanabe Y, Dohi S, Iida H, Ishiyama T, Tashiro T, Shimonaka H
Department of Anesthesiology and Critical Care Medicine, Gifu University School of Medicine.
Masui. 1995 Aug;44(8):1097-101.
To evaluate the effects of systemic bupivacaine on the baroreflex control of heart rate, we investigated the baroreflex sensitivity assessed with a pressor and a depressor test using phenylephrine and nitroglycerin in pentobarbital anesthetized dogs (n = 12). Intravenous injection of bupivacaine (mean plasma concentration of 2.4 +/- 0.9 micrograms.ml-1) caused a significant suppression of the baroreflex sensitivity, defined by the slopes of regression line (in msec of RR interval change per mmHg increase or decrease in systolic blood pressure). The sensitivity obtained with the pressor and the depressor tests decreased from 6.0 +/- 2.3 to 3.5 +/- 1.7, from 2.4 +/- 1.3 to 1.3 +/- 0.8 msec.mmHg-1, respectively (P < 0.01). Suppression of the baroreflex sensitivity during epidural anesthesia with bupivacaine could be due not only to cardiac sympathectomy but also to a direct effect of bupivacaine on the reflex arch including the receptors, the afferent nerve pathways, the CNS, the efferent pathway, and the effector organs. Therefore, the hemodynamic responses to reduction of blood pressure are likely to be inhibited by epidural bupivacaine.
为评估全身应用布比卡因对心率压力反射控制的影响，我们在戊巴比妥麻醉的犬（n = 12）中，使用去氧肾上腺素和硝酸甘油通过升压和降压试验来研究压力反射敏感性。静脉注射布比卡因（平均血浆浓度为2.4±0.9微克·毫升⁻¹）导致压力反射敏感性显著降低，压力反射敏感性由回归线斜率定义（收缩压每升高或降低1 mmHg时RR间期变化的毫秒数）。升压和降压试验所测得的敏感性分别从6.0±2.3降至3.5±1.7，从2.4±1.3降至1.3±0.8毫秒·毫米汞柱⁻¹（P < 0.01）。布比卡因硬膜外麻醉期间压力反射敏感性的降低可能不仅归因于心脏交感神经切除术，还可能是布比卡因对反射弧（包括感受器、传入神经通路、中枢神经系统、传出通路和效应器器官）的直接作用。因此，硬膜外布比卡因可能会抑制对血压降低的血流动力学反应。
