Turner William, Boonstra Linda, Maxwell Cynthia, Downey Kristy, Balki Mrinalini
Department of Anesthesia and Pain Management, Mount Sinai Hospital, Mount Sinai Toronto, ON, Canada.
Department of Anesthesiology & Pain Medicine, University of Toronto, Toronto, ON, Canada.
Can J Anaesth. 2025 Mar;72(3):426-435. doi: 10.1007/s12630-024-02891-2. Epub 2025 Jan 6.
Class III obesity (body mass index [BMI] ≥ 40 kg·m) is associated with high rates of Cesarean deliveries and postpartum hemorrhage, with increased maternal and fetal morbidity. The doses of oxytocin and carbetocin are two to four times higher at Cesarean delivery in patients with class III obesity. We sought to investigate the efficacy of carbetocin 80 µg iv compared with oxytocin 1 IU iv (plus infusion) at elective Cesarean delivery in parturients with class III obesity. We hypothesized that, with equipotent dosing, carbetocin would be noninferior to oxytocin.
We conducted a randomized, double-blind, noninferiority study in nonlabouring, term parturients with BMI ≥ 40 kg·m undergoing elective Cesarean delivery under neuraxial anesthesia. Patients received either a 1-IU bolus of oxytocin iv followed by an infusion of 4.8 IU·hr or an 80-µg carbetocin bolus iv followed by a placebo infusion. Uterine tone was determined by palpation by the obstetrician at 3, 5, and 10 min, using a verbal numerical rating score of 0 (boggy) to 10 (firm). The primary outcome was uterine tone at 3 min. Secondary outcomes included uterine tone at 5 and 10 min, blood loss, additional uterotonics, and side effects.
Forty-seven participants were included in the analysis. Median tone at 3 min was similar for oxytocin (8; 95% confidence interval [CI], 7 to 8) and carbetocin (8; 95% CI, 8 to 9) (P = 0.06), with no difference at 5 and 10 min. Blood loss, side effects, and the need for additional uterotonics were not significantly different between the study groups.
We conclude that carbetocin is noninferior to oxytocin at elective Cesarean delivery in parturients with class III obesity, with the advantage of single bolus dosing without infusion.
ClinicalTrials.gov ( NCT04902729 ); first submitted 21 May 2021.
Ⅲ级肥胖（体重指数[BMI]≥40kg·m²）与剖宫产率和产后出血率高相关，会增加母婴发病率。Ⅲ级肥胖患者剖宫产时缩宫素和卡贝缩宫素的剂量比正常情况高两到四倍。我们旨在研究在择期剖宫产时，静脉注射80μg卡贝缩宫素与静脉注射1IU缩宫素（加静脉输注）相比，对Ⅲ级肥胖产妇的疗效。我们假设，在等效剂量下，卡贝缩宫素不劣于缩宫素。
我们对BMI≥40kg·m²、未临产、足月且接受择期剖宫产的产妇进行了一项随机、双盲、非劣效性研究，产妇在神经轴麻醉下进行手术。患者要么静脉注射1IU缩宫素推注，随后以4.8IU·hr的速度静脉输注，要么静脉注射80μg卡贝缩宫素推注，随后静脉输注安慰剂。产科医生在3、5和10分钟时通过触诊确定子宫张力，使用0（松软）至10（坚硬）的口头数字评分。主要结局是3分钟时的子宫张力。次要结局包括5分钟和10分钟时的子宫张力、失血量、额外使用的宫缩剂和副作用。
47名参与者纳入分析。缩宫素组3分钟时的子宫张力中位数为8（95%置信区间[CI]，7至8），卡贝缩宫素组为8（95%CI，8至9）（P=0.06），5分钟和10分钟时无差异。两组间失血量、副作用以及额外使用宫缩剂的需求无显著差异。
我们得出结论，在Ⅲ级肥胖产妇的择期剖宫产中，卡贝缩宫素不劣于缩宫素，其优点是单次推注给药无需输注。
ClinicalTrials.gov（NCT04902729）；于2021年5月21日首次提交。
