Epidural anesthesia, hypotension, and changes in intravascular volume
Epidural anesthesia, hypotension, and changes in intravascular volume
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DOI：
10.1097/00000542-200402000-00016
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发表时间：
2004-02-01
期刊：
影响因子：
8.8
通讯作者：
Kehlet, H
中科院分区：
文献类型：
--
作者：
Holte, K;Foss, NB;Kehlet, H
背景资料：硬膜外麻醉或脊髓麻醉最常见的副作用是低血压伴功能性血容量减少，需要输液或使用血管加压药。在接受腰椎硬膜外麻醉的患者中进行的短期研究（20分钟）表明，当存在低血压时，血浆容量可能会增加，这可能对低血压治疗的选择有影响。然而，没有长期的信息或测量血浆量与或不与低血压后硬膜外anesthesias.Methods：在12名健康志愿者，作者评估了血浆（I-125-白蛋白）和红细胞（Cr-51-EDTA）的体积前和90分钟后，10毫升布比卡因，0.5%，通过胸硬膜外导管（T7-T10）。90分钟后（t = 90），受试者被随机分配到液体（7 ml/kg羟乙基淀粉）或血管加压药（0.2 mg/kg麻黄碱），40分钟后（t = 130），血浆和红细胞体积进行了测量。在同一时间点，测量平均红细胞体积和红细胞压积。在整个研究过程中，每5分钟测量一次收缩压和舒张压、心率和血红蛋白。容量动力学分析进行了志愿者接受羟乙基starch.Results：血浆容量本身并没有改变胸段硬膜外麻醉后，尽管血压下降。血浆容量随着液体给药而增加，但血管加压药保持不变;尽管两种治疗具有相似的血流动力学效应。血红蛋白浓度没有显着改变硬膜外阻滞或麻黄碱管理，但羟乙基淀粉管理后显着下降。体积动力学分析表明，输注的液体膨胀了相当小的体积，约为1.5 l。消除常数为56 ml/min。结论：胸段硬膜外麻醉本身不会导致血容量的变化，尽管血压降低。当输注液体时，存在稀释，并且液体最初似乎位于中心。由于羟乙基淀粉和麻黄碱的给药具有相似的血流动力学效应，后者可能是心肺疾病患者的首选，其中围手术期液体超负荷是不可取的。
Background: The most common side effect of epidural or spinal anesthesia is hypotension with functional hypovolemia prompting fluid infusions or administration of vasopressors. Short-term studies (20 min) in patients undergoing lumbar epidural anesthesia suggest that plasma volume may increase when hypotension is present, which may have implications for the choice of treatment of hypotension. However, no long-term information or measurements of plasma volumes with or without hypotension after epidural anesthesia are available.Methods: In 12 healthy volunteers, the authors assessed plasma (I-125-albumin) and erythrocyte (Cr-51-EDTA) volumes before and 90 min after administration of 10 ml bupivacaine, 0.5%, via a thoracic epidural catheter (T7-T10). After 90 min (t = 90), subjects were randomized to administration of fluid (7 ml/kg hydroxyethyl starch) or a vasopressor (0.2 mg/kg ephedrine), and 40 min later (t = 130), plasma and erythrocyte volumes were measured. At the same time points, mean corpuscular volume and hematocrit were measured. Systolic and diastolic blood pressure, heart rate, and hemoglobin were measured every 5 min throughout the study. Volume kinetic analysis was performed for the volunteers receiving hydroxyethyl starch.Results: Plasma volume did not change per se after thoracic epidural anesthesia despite a decrease in blood pressure. Plasma volume increased with fluid administration but remained unchanged with vasopressors; despite that both treatments had similar hemodynamic effects. Hemoglobin concentrations were not significantly altered by the epidural blockade or ephedrine administration but decreased significantly after hydroxyethyl starch administration. Volume kinetic analysis showed that the infused fluid expanded a rather small volume, approximately 1.5 l. The elimination constant was 56 ml/min.Conclusions: Thoracic epidural anesthesia per se does not lead to changes in blood volumes despite a reduction in blood pressure. When fluid is infused, there is a dilution, and the fluid initially seems to be located centrally. Because administration of hydroxyethyl starch and ephedrine has similar hemodynamic effects, the latter may be preferred in patients with cardiopulmonary diseases in which perioperative fluid overload is undesirable.