体重调节去甲肾上腺素输注量预防剖宫产术中腰硬联合麻醉低血压：随机双盲剂量-反应研究
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A randomised double-blind dose-response study of weight-adjusted infusions of norepinephrine for preventing hypotension during combined spinal-epidural anaesthesia for Caesarean delivery
背景与目的
输注去甲肾上腺素是预防剖宫产术中腰麻低血压的有效方法。然而，去甲肾上腺素的最佳给药方案尚未确定。本研究旨在探讨剖宫产腰麻过程中，体重调节、固定速率输注去甲肾上腺素预防低血压的剂量-反应特征。
方 法
本项双盲随机对照试验共收集了80例施行择期剖宫产的产妇，并分别于腰硬联合麻醉诱导后立即预防性输注去甲肾上腺素：0.025μg kg-1 min-1（N1组）、0.05μg kg-1 min-1（N2组）、0.075μg kg-1 min-1（N3组）或0.10μg kg-1 min-1（N4组）。主要结果为未发生低血压，定义为分娩前收缩压降低≥基线值20%或≤90mm Hg。50%有效剂量（ED50）和ED90值采用概率回归计算。
结 果
N1、N2、N3、N4组低血压发生率分别为11/20(55%)、6/20(30%)、2/20(10%)、1/20 (5%)(P<0.0001)。去甲肾上腺素预防低血压的ED50和ED90(95%CI)分别为0.029(-0.002 ~ 0.043)和0.080 (0.065~0.116)mg kg-1 min-1。反应性高血压的发生率随去甲肾上腺素剂量的增加而增加(P=0.002)。其他不良反应组间相似。
结 论
本研究表明，输注去甲肾上腺素0.08 mg kg-1 min-1 可有效预防90%患者的低血压。这一结果可为去甲肾上腺素输注的初始剂量提供指导。
原始文献摘要
Fu F, Xiao F, Chen W, et al. A randomised double-blind dose-response study of weight-adjusted infusions of norepinephrine for preventing hypotension during combined spinal-epidural anaesthesia for Caesarean delivery.[J]. Br J Anaesth 2020 Mar;124(3).
Background: Norepinephrine infusion has been suggested as an effective method for preventing hypotension during spinal anaesthesia for Caesarean delivery. However, optimal dosing regimens for norepinephrine have not been well established. This study aimed to determine the dose-response characteristics of a weight-adjusted fixed-rate infusion of norepinephrine to prevent hypotension during neuraxial anaesthesia for Caesarean delivery.
Methods: In a double-blind, randomised controlled trial, 80 parturients having elective Caesarean delivery received a prophylactic norepinephrine infusion at 0.025 μg kg-1 min-1 (Group N1), 0.05 μg kg-1 min-1 (Group N2), 0.075 μg kg-1 min-1 (Group N3), or 0.10 μg kg-1 min-1 (Group N4), starting immediately after induction of combined spinal-epidural anaesthesia. The primary outcome was non-occurrence of hypotension, defined as a decrease in systolic arterial pressure≥ 20% below baseline value or to ≤90 mm Hg, before delivery. Values for 50% effective dose (ED50) and ED90 were calculated using probit regression.
Results: The incidence of hypotension was 11/20 (55%), 6/20 (30%), 2/20 (10%), and 1/20 (5%) in Groups N1, N2, N3, and N4, respectively (P<0.0001). The ED50 and ED90 (95% confifidence interval) of norepinephrine infusions for preventing hypotension were 0.029 (-0.002 to 0.043) and 0.080 (0.065~0.116) mg kg-1 min-1 , respectively. The incidence of reactive hypertension increased with increasing norepinephrine dose (P=0.002). Other adverse effects were similar among groups.
Conclusions: Under the conditions of this study, an infusion of norepinephrine 0.08 mg kg-1 min-1 was effective for preventing hypotension in 90% of patients. This information should provide a guide for initiating norepinephrine infusions.
麻醉学文献进展分享
贵州医科大学高鸿教授课题组
翻译：冯玉蓉 编辑：冯玉蓉 审校：王贵龙