Department of Anesthesiology, Stanford University, Stanford, CA, USA.
Int J Obstet Anesth. 2012 Jan;21(1):29-34. doi: 10.1016/j.ijoa.2011.09.002. Epub 2011 Nov 18.
Previous studies have demonstrated that the addition of intrathecal fentanyl to a spinal anesthetic for cesarean delivery improves intraoperative analgesia. However, intrathecal fentanyl may induce acute tolerance to opioids. The objective of this study was to investigate whether the addition of intrathecal fentanyl to spinal anesthesia with intrathecal morphine increases postoperative analgesic requirements and pain scores.
In this randomized, double-blinded study, 40 women having elective cesarean delivery were enrolled. Patients received spinal anesthesia with hyperbaric bupivacaine 12 mg, morphine 200 μg, and fentanyl 0, 5, 10 or 25 μg. Each patient received intravenous patient-controlled analgesia morphine for 24h postoperatively. Outcome measures included postoperative morphine usage and pain scores, as well as intraoperative pain, nausea, hypotension and vasopressor use.
Total morphine use over the 24-h post-spinal study period was similar among the study groups (P=0.129). Postoperative pain scores were higher in patients receiving fentanyl 5, 10 and 25 μg compared to fentanyl 0 μg control group (P=0.003).
The study results suggest that intrathecal fentanyl may induce acute tolerance to intrathecal morphine. However, because there was no difference in postoperative analgesia requirement and the difference in pain scores was small, the clinical significance of this finding is uncertain.
先前的研究表明，在剖宫产术中鞘内给予芬太尼可改善术中镇痛效果。然而，鞘内给予芬太尼可能会导致阿片类药物的急性耐受。本研究旨在探讨鞘内给予吗啡的脊髓麻醉中鞘内给予芬太尼是否会增加术后镇痛需求和疼痛评分。
在这项随机、双盲研究中，纳入了 40 名择期行剖宫产术的妇女。患者接受布比卡因 12mg、吗啡 200μg 和芬太尼 0、5、10 或 25μg 的鞘内麻醉。每位患者术后均接受静脉自控镇痛吗啡 24 小时。观察指标包括术后吗啡用量和疼痛评分以及术中疼痛、恶心、低血压和血管加压药使用情况。
鞘内研究期间 24 小时内的总吗啡用量在各研究组之间相似（P=0.129）。与芬太尼 0μg 对照组相比，接受芬太尼 5、10 和 25μg 的患者术后疼痛评分更高（P=0.003）。
研究结果表明，鞘内给予芬太尼可能会导致鞘内给予吗啡的急性耐受。然而，由于术后镇痛需求无差异，且疼痛评分差异较小，因此该发现的临床意义尚不确定。
