Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Xueshi Road 1, Hangzhou, 310006, China.
Department of Anesthesiology and Perioperative Medicine, Tufts Medical Center, Boston, MA, USA.
Clin Drug Investig. 2021 Dec;41(12):1047-1053. doi: 10.1007/s40261-021-01090-x. Epub 2021 Oct 16.
While oxytocin is commonly used for the prevention of uterine atony, its pharmacology may be affected by a prior history of caesarean delivery. The objective of this study was to determine the 50% effective dose (ED) of bolus oxytocin after caesarean delivery in parturients with and without prior caesarean delivery.
This was a parallel-group, double-blind, dose-response study using Dixon's up-and-down sequential allocation method to estimate the ED of bolus-administered oxytocin in parturients having caesarean delivery under combined spinal-epidural anaesthesia (CSE). Twenty-seven parturients with a history of prior caesarean delivery (With-PCD group) and 26 parturients with no such history (Without-PCD group) were enrolled. Oxytocin was administered as an intravenous bolus at a starting dose of 0.5 units, which was then increased or decreased by 0.25 units at a time. Uterine tone was assessed by the obstetrician as either 'adequate' or 'inadequate' 3 min after delivery of the fetus. Adverse effects, administration of additional uterotonic agents, and estimated blood loss were recorded.
The ED of oxytocin was greater in the With-PCD group than in the Without-PCD group (0.95 units [95% CI 0.82-1.08] vs. 0.55 units [95% CI 0.38-0.73], P < 0.001). The overall incidence of adverse effects was higher in the With-PCD group than in the Without-PCD group (33.3% vs. 7.7%, P = 0.02).
The initial bolus dose of oxytocin needed to prevent uterine atony was higher in parturients with prior caesarean delivery than in parturients without prior caesarean delivery. Uterine scarring may contribute to the increased oxytocin requirements of the former group.
ChiCTR1900023474; investigator: Wei CN; date of registration: 30 May 2019.
虽然催产素常用于预防子宫收缩乏力，但它的药理学可能会受到先前剖宫产史的影响。本研究的目的是确定有和没有先前剖宫产史的产妇在剖宫产时给予催产素负荷剂量的 50%有效剂量（ED）。
这是一项平行组、双盲、剂量反应研究，使用 Dixon 的上下序贯分配法来估计椎管内麻醉下剖宫产产妇给予催产素负荷剂量的 ED。共有 27 例有先前剖宫产史的产妇（有 PC 组）和 26 例无此类病史的产妇（无 PC 组）入组。催产素以 0.5 单位的起始剂量静脉推注，然后每次增加或减少 0.25 单位。胎儿娩出后 3 分钟，由产科医生评估子宫收缩情况为“足够”或“不足”。记录不良反应、给予额外的子宫收缩剂和估计失血量。
有 PC 组的催产素 ED 大于无 PC 组（0.95 单位[95%CI 0.82-1.08]比 0.55 单位[95%CI 0.38-0.73]，P<0.001）。有 PC 组的不良反应总发生率高于无 PC 组（33.3%比 7.7%，P=0.02）。
有先前剖宫产史的产妇预防子宫收缩乏力所需的催产素初始负荷剂量高于无先前剖宫产史的产妇。子宫瘢痕可能导致前者对催产素的需求增加。
ChiCTR1900023474；研究者：陈伟；注册日期：2019 年 5 月 30 日。
