Poon Yan-Yuen, Liu Yueh-Wei, Huang Ya-Hui, Chan Samuel H H, Tsai Ching-Yi
Department of Anesthesiology, Chang Gung Memorial Hospital, Kaohsiung 83301, Taiwan.
Institute for Translational Research in Biomedicine, Chang Gung Memorial Hospital, Kaohsiung 83301, Taiwan.
Biology (Basel). 2021 Jul 2;10(7):617. doi: 10.3390/biology10070617.
Spinal anesthesia is generally accepted as an effective and safe practice. Three rare incidents of postoperative cerebral infarction after surgery under spinal anesthesia prompted us to assess whether spinal bupivacaine may compromise carotid or cerebral blood flow. Postoperative examination after the stroke incident revealed that all three patients shared a common pathology of stenosis or atheromatosis in the carotid or middle cerebral artery. In a companion study using 69 Sprague-Dawley rats, subarachnoid application of bupivacaine elicited an initial (Phase I) reduction in the mean arterial pressure, carotid blood flow (CBF) and baroreflex-mediated sympathetic vasomotor tone, all of which subsequently returned to baseline (Phase II). Whereas heart rate (HR) exhibited sustained reduction, cardiac vagal baroreflex, baroreflex efficiency index (BEI) and tissue perfusion and oxygen in the cerebral cortex remained unaltered. However, in one-third of the rats studied, Phase II gave way to Phase III characterized by secondary hypotension and depressed baroreflex-mediated sympathetic vasomotor tone, along with declined HR, sustained cardiac vagal baroreflex, decreased BEI, reduced CBF and waning tissue perfusion or oxygen in the cerebral cortex. We concluded that carotid and cerebral blood flow can indeed be compromised after spinal anesthesia, and an impaired baroreflex-mediated sympathetic vasomotor tone, which leads to hypotension, plays a contributory role.
脊髓麻醉通常被认为是一种有效且安全的操作方法。三例脊髓麻醉术后罕见的脑梗死事件促使我们评估布比卡因脊髓麻醉是否会损害颈动脉或脑血流。中风事件后的术后检查显示，所有三名患者在颈动脉或大脑中动脉均存在狭窄或动脉粥样硬化的共同病理特征。在一项使用69只Sprague-Dawley大鼠的配套研究中，蛛网膜下腔应用布比卡因引发了平均动脉压、颈动脉血流量（CBF）和压力反射介导的交感神经血管运动张力的初始（I期）降低，所有这些随后均恢复至基线水平（II期）。而心率（HR）则持续降低，心脏迷走神经压力反射、压力反射效率指数（BEI）以及大脑皮质的组织灌注和氧含量保持不变。然而，在三分之一的研究大鼠中，II期转变为III期，其特征为继发性低血压、压力反射介导的交感神经血管运动张力降低，同时伴有心率下降、持续的心脏迷走神经压力反射、BEI降低、CBF减少以及大脑皮质组织灌注或氧含量下降。我们得出结论，脊髓麻醉后颈动脉和脑血流确实可能受到损害，压力反射介导的交感神经血管运动张力受损导致低血压，这起到了一定作用。
