Ben-David B, Miller G, Gavriel R, Gurevitch A
Department of Anesthesia, Allegheny General Hospital, Pittsburgh, Pennsylvania 15212, USA.
Reg Anesth Pain Med. 2000 May-Jun;25(3):235-9.
The hypotension following spinal anesthesia remains commonplace in cesarean delivery. Intrathecal opioids are synergistic with local anesthetics and intensify sensory block without increasing sympathetic block. The combination makes it possible to achieve spinal anesthesia with otherwise inadequate doses of local anesthetic. We hypothesized that this phenomenon could be used to provide spinal anesthesia for cesarean delivery while incurring less frequent hypotension.
Thirty-two women scheduled for cesarean delivery were divided into 2 groups of patients who received a spinal injection of either 10 mg of isobaric (plain) bupivacaine 0.5% or 5 mg of isobaric bupivacaine with 25 microg fentanyl added. Each measurement of a systolic blood pressure less than 95 mm Hg or a decrease in systolic pressure of greater than 25% from baseline was considered as hypotension and treated with a bolus of 5 to 10 mg of intravenous ephedrine.
Spinal block provided surgical anesthesia in all patients. Peak sensory level was higher (T3 v T4. 5) and motor block more intense in the plain bupivacaine group. The plain bupivacaine patients were more likely to require treatment for hypotension (94% v 31%) and had more persistent hypotension (4.8 v 0.6 hypotensive measurements per patient) than patients in the minidose bupivacaine-fentanyl group. Mean ephedrine requirements were 23.8 mg and 2.8 mg, respectively, for the 2 groups. Patients in the plain bupivacaine group also complained of nausea more frequently than patients in the minidose bupivacaine-fentanyl group (69% v 31%).
Bupivacaine 5 mg + fentanyl 25 microg provided spinal anesthesia for cesarean delivery with less hypotension, vasopressor requirements, and nausea than spinal anesthesia with 10 mg bupivacaine.
剖宫产术中腰麻后低血压仍很常见。鞘内注射阿片类药物与局部麻醉药具有协同作用，可增强感觉阻滞而不增加交感神经阻滞。这种联合使用使得使用原本剂量不足的局部麻醉药就能实现腰麻成为可能。我们推测这种现象可用于为剖宫产提供腰麻，同时减少低血压的发生频率。
32例计划行剖宫产的女性被分为2组，分别接受鞘内注射10mg等比重（普通）0.5%布比卡因或5mg等比重布比卡因加25μg芬太尼。收缩压低于95mmHg或收缩压较基线下降超过25%的每次测量都被视为低血压，并给予5至10mg静脉麻黄碱推注治疗。
所有患者均通过腰麻获得了手术麻醉。普通布比卡因组的感觉阻滞峰值水平更高（T3对T4.5），运动阻滞更强。与小剂量布比卡因-芬太尼组患者相比，普通布比卡因组患者更有可能需要治疗低血压（94%对31%），且低血压持续时间更长（每位患者低血压测量次数为4.8次对0.6次）。两组的平均麻黄碱需求量分别为23.8mg和2.8mg。普通布比卡因组患者恶心的主诉也比小剂量布比卡因-芬太尼组患者更频繁（69%对31%）。
与10mg布比卡因腰麻相比，5mg布比卡因+25μg芬太尼用于剖宫产腰麻时，低血压、血管升压药需求量和恶心发生率更低。
