去甲肾上腺素预防剖宫产腰硬联合麻醉后低血压的90%有效剂量的临床研究

A clinical research of ED90 norepinephrine to prevent hypotension after combined spinal and epidural anesthesia during cesarean delivery

目的·通过序贯分析法确定择期剖宫产蛛网膜下腔联合硬膜外麻醉(腰硬联合麻醉)后90%产妇不发生低血压的去甲肾上腺素静脉推注剂量。方法·根据偏倚钱币序贯法依次对40例择期剖宫产的产妇进行前瞻性双盲序贯研究。主要观察指标为胎儿娩出前维持产妇收缩压高于其基础值80%所使用的去甲肾上腺素静脉推注剂量。次要观察指标包括头晕、胸闷、恶心、呕吐、心动过缓、继发性高血压、补救性使用阿托品的发生率、补救性使用去甲肾上腺素的发生率,以及新生儿1 min和5 min Apgar评分等。使用Isotonic回归分析估计90%有效剂量(90%effective dose,ED_(90))及其95%CI。结果·腰硬联合麻醉后预防性静脉推注去甲肾上腺素维持产妇血压的ED_(90)为[10.85(95%CI 9.20~11.67)]μg。产妇头晕、胸闷、恶心的发生率分别为2.5%、7.5%和10.0%,补救性使用去甲肾上腺素发生率为5.0%;未出现呕吐、心动过缓、继发性高血压及补救性使用阿托品。所有新生儿1 min及5 min Apgar评分均为10分。结论·建议剖宫产腰硬联合麻醉后单次静脉推注去甲肾上腺素11μg,以预防产妇麻醉后低血压的发生。

Objective·To determine the optimal intravenous norepinephrine bolus dose needed to prevent hypotension after combined spinal and epidural anesthesia in 90%of women during elective cesarean delivery.Methods·Forty women undergoing elective cesarean delivery were allocated into this double-blinded,prospective,and sequential dose-finding study using biased coin design sequential method.The primary outcome was the successful use of the norepinephrine bolus dose to maintain systolic blood pressure above 80%of the baseline until delivery.Secondary outcomes included dizziness,breathlessness,nausea,vomiting,bradycardia,secondary hypertension and supplemental use of atropine or norepinephrine of the women,as well as 1 min and 5 min Apgar scores of the newborns.The 90%effective dose(ED90)and its 95%CI were estimated using Isotonic regression methods.Results·The estimated ED90 intravenous bolus dose of norepinephrine was[10.85(95%CI 9.20-11.67)]μg to prevent hypotension after combined spinal and epidural anesthesia during cesarean delivery.The occurrence rates of dizziness,breathlessness,and nausea were 2.5%,7.5%and 10.0%,respectively.The occurrence rate of additional rescue norepinephrine boluses was 5.0%.No vomiting,bradycardia,secondary hypertension and supplemental use of atropine appeared.Apgar scores of all newborns at 1 min and 5 min were 10.Conclusion·An intravenous norepinephrine bolus dose of 11μg is recommended to prevent hypotension after combined spinal and epidural anesthesia during cesarean delivery for clinical practice.