Department of Anaesthesia, Maternal and Infant Care Research Center, Mount Sinai Hospital, University of Toronto, ON, Canada.
Department of Anaesthesiology and Pain Medicine and Department of Obstetrics and Gynaecology, University of Toronto, ON, Canada.
Anaesthesia. 2021 Jul;76(7):918-923. doi: 10.1111/anae.15322. Epub 2020 Nov 23.
Prophylactic oxytocin administration at the third stage of labour reduces blood loss and the need for additional uterotonic drugs. Obesity is known to be associated with an increased risk of uterine atony and postpartum haemorrhage. It is unknown whether women with obesity require higher doses of oxytocin in order to achieve adequate uterine tone after delivery. The purpose of this study was to establish the bolus dose of oxytocin required to initiate effective uterine contraction in 90% of women with obesity (the ED ) at elective caesarean delivery. We conducted a double-blind dose-finding study using the biased coin up-down design method. Term pregnant women with a BMI ≥ 40 kg.m undergoing elective caesarean delivery under regional anaesthesia were included. Those with conditions predisposing to postpartum haemorrhage were not included. Oxytocin was administered as an intravenous bolus over 1 minute upon delivery of the fetus. With the first woman receiving 0.5 IU, oxytocin doses were administered according to a sequential allocation scheme. The primary outcome measure was satisfactory uterine tone, as assessed by the operating obstetrician 2 minutes after administration of the oxytocin bolus. Secondary outcomes included the need for rescue uterotonic drugs, adverse effects and estimated blood loss. We studied 30 women with a mean (SD) BMI of 52.3 (7.6) kg.m . The ED for oxytocin was 0.75 IU (95%CI 0.5-0.93 IU) by isotonic regression and 0.78 IU (95%CI 0.68-0.88 IU) by the Dixon and Mood method. Our results suggest that women with a BMI ≥ 40 kg.m require approximately twice as much oxytocin as those with a BMI < 40 kg.m , in whom an ED of 0.35 IU (95%CI 0.15-0.52 IU) has previously been demonstrated.
在分娩第三阶段预防性给予催产素可减少出血量和对额外子宫收缩药物的需求。肥胖已知与子宫收缩乏力和产后出血的风险增加有关。尚不清楚肥胖妇女在分娩后是否需要更高剂量的催产素才能达到足够的子宫收缩。本研究旨在确定在择期剖宫产时，肥胖妇女（ED）中 90%的人需要多大剂量的催产素才能开始有效的子宫收缩。我们使用偏倚硬币上下设计方法进行了一项双盲剂量发现研究。纳入了 BMI≥40kg/m2、接受区域麻醉择期剖宫产的足月孕妇。不包括易发生产后出血的孕妇。胎儿娩出后 1 分钟内静脉推注催产素。第一位接受 0.5IU 催产素的女性，根据序贯分配方案给予催产素剂量。主要结局测量指标为给药后 2 分钟手术产科医生评估的满意子宫收缩情况。次要结局包括需要抢救性子宫收缩药物、不良反应和估计失血量。我们研究了 30 名平均（SD）BMI 为 52.3（7.6）kg/m2 的女性。催产素的 ED 为 0.75IU（95%CI 0.5-0.93IU），通过等渗回归和 0.78IU（95%CI 0.68-0.88IU）通过 Dixon 和 Mood 方法。我们的结果表明，BMI≥40kg/m2 的女性需要的催产素大约是 BMI<40kg/m2 的女性的两倍，先前已证明后者的 ED 为 0.35IU（95%CI 0.15-0.52IU）。
