Whitty R, Goldszmidt E, Parkes R K, Carvalho J C A
Department of Anesthesia and Pain Management, Mount Sinai Hospital, Toronto, Ontario, Canada.
Int J Obstet Anesth. 2007 Oct;16(4):341-5. doi: 10.1016/j.ijoa.2007.06.004. Epub 2007 Aug 13.
Combined spinal-epidural (CSE) analgesia is an effective technique for pain control in labor and is particularly useful in the active phase. Excessive doses of intrathecal bupivacaine may be associated with adverse effects. This study is designed to estimate the ED95 for intrathecal plain bupivacaine with fentanyl 15 microg in labor.
Forty healthy women in active labor (cervical dilatation > or = 5 cm and verbal numeric pain score > or = 6/10) were given CSE for labor analgesia with intrathecal plain bupivacaine and fentanyl 15 microg. The initial dose of bupivacaine was 1.75 mg. Doses were varied in a 0.25-mg testing interval according to a method of sequential allocation designed to cluster the dose around the ED95. Effectiveness was defined as a verbal numeric pain score < or = 1 within 10 min of intrathecal injection.
There was a 100% response rate to the 1.75-mg dose (95% CI 84.6-100.0%) and an 85.0% response rate to 1.50 mg (95% CI 64.0-95.8%). The ED95 for intrathecal plain bupivacaine with fentanyl 15 microg in active labor was 1.66 mg (95% CI 1.50-482.5 mg). The incidence of fetal bradycardia was 7.5%. The incidence of pruritus was 55%. No patient experienced motor block.
This is the first dose-finding study specifically designed to estimate the ED95 of intrathecal bupivacaine combined with a fixed amount of fentanyl for analgesia in active labor. The combination of bupivacaine 1.75 mg with fentanyl 15 microg rapidly and reliably alleviated pain in the active phase of labor.
腰麻-硬膜外联合（CSE）镇痛是分娩期疼痛控制的有效技术，在活跃期尤为有用。鞘内注射布比卡因剂量过大可能会产生不良反应。本研究旨在评估分娩时鞘内注射15微克芬太尼的单纯布比卡因ED95。
40名活跃期健康产妇（宫颈扩张≥5cm且言语数字疼痛评分≥6/10）接受CSE分娩镇痛，鞘内注射单纯布比卡因和15微克芬太尼。布比卡因初始剂量为1.75mg。根据旨在将剂量聚集在ED95周围的序贯分配方法，以0.25mg的测试间隔改变剂量。有效性定义为鞘内注射后10分钟内言语数字疼痛评分≤1。
1.75mg剂量的有效率为100%（95%CI 84.6-100.0%），1.50mg剂量的有效率为85.0%（95%CI 64.0-95.8%）。分娩活跃期鞘内注射15微克芬太尼的单纯布比卡因ED95为1.66mg（95%CI 1.50-482.5mg）。胎儿心动过缓发生率为7.5%。瘙痒发生率为55%。无患者出现运动阻滞。
这是第一项专门设计用于评估鞘内注射布比卡因联合固定剂量芬太尼用于分娩活跃期镇痛的ED95的剂量探索研究。1.75mg布比卡因与15微克芬太尼联合可迅速、可靠地缓解分娩活跃期疼痛。
