BACKGROUND The 90% effective dose (ED90) of oxytocin infusion has been previously estimated to be 16.2 IU h- 1. However, bolus administration of oxytocin prior to the infusion may decrease the infusion dose required. The aim of this study was to estimate the ED95 for oxytocin infusion after a bolus at elective caesarean delivery (CD) in nonlaboring parturients. METHODS We performed a randomized, triple blinded study in 150 healthy termparturients scheduled for elective CD under epidural anaesthesia. After delivery of the infant and i.v. administration of 1 IU oxytocin as a bolus, Participants were randomized to receive oxytocin infusion at a rate of 0, 1, 2, 3, 5, or 8 IU h- 1, to be given for a total of 1 h. Uterine tone assessed by the blinded obstetrician as either adequate or inadequate. Secondary outcomes included estimated blood loss (EBL), requirement for supplemental uterotonic agents, and development of side effects. RESULTS The 95% effective dose (ED95) of oxytocin infusion was estimated to be 7.72 IU h- 1 (95% confidence interval 5.80-12.67 IU h- 1). With increasing oxytocin infusion rate, the proportion of parturients who needed rescue oxytocin bolus or secondary uterotonic agents decreased. No significant among-group differences in the EBL and oxytocin-related side effects were observed. CONCLUSIONS In parturients who receive a 1 IU bolus of oxytocin during elective cesarean delivery, an infusion rate of oxytocin at 7.72 IU h- 1 will produce adequate uterine tone in 95% of parturients. These results suggest that the total dose of oxytocin administered in the postpartum period can be decreased when administered as an infusion after oxytocin bolus.

中文翻译：

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催产素输注速率的ED50和ED95在择期剖腹产过程中维持子宫张力的剂量发现研究。

背景技术以前已经估计催产素输注的90％有效剂量（ED90）为16.2 IU h-1。但是，在输注之前推注催产素可能会减少所需的输注剂量。这项研究的目的是评估在不分娩的产妇进行选择性剖腹产（CD）推注大剂量推注催产素后的ED95。方法我们对150名健康的足月分娩的硬膜外麻醉下进行选择性CD的患者进行了一项随机，三盲研究。分娩婴儿并静脉推注1 IU催产素后，随机分配参与者接受催产素输注的速率为0、1、2、3、5或8 IU h-1，总计1小时 盲产科医生认为子宫色调足够或不足。次要结果包括估计的失血量（EBL），补充宫缩剂的需求，以及副作用的发展。结果催产素输注的95％有效剂量（ED95）估计为7.72 IU h-1（95％置信区间5.80-12.67 IU h-1）。随着催产素输注速率的增加，需要急诊催产素推注或次生子宫收缩剂的产妇比例下降。没有观察到EBL和催产素相关副作用的组间显着差异。结论在选择性剖宫产期间接受1 IU催产素推注的分娩者中，以7.72 IU h-1输注催产素将使95％的分娩者产生足够的子宫张力。这些结果表明，当在催产素推注之后以输注方式施用时，可以降低产后时期催产素的总剂量。