Balki Mrinalini, Erik-Soussi Magda, Kingdom John, Carvalho Jose C A
Department of Anesthesia and Pain Management, Mount Sinai Hospital, University of Toronto, 600 University Avenue, Room 19-104, Toronto, ON, M5G 1X5, Canada,
Can J Anaesth. 2014 Sep;61(9):808-18. doi: 10.1007/s12630-014-0190-1. Epub 2014 Jun 7.
To compare the in vitro contractile responses to oxytocin, ergonovine, prostaglandin F2 alpha (PGF2α), and misoprostol in isolated myometrium from non-labouring and labouring pregnant women.
Myometrial strips obtained from labouring (with or without oxytocin augmentation) and non-labouring women undergoing Cesarean deliveries were subjected to a dose-response testing with oxytocin, ergonovine, PGF2α, or misoprostol (10(-10) M to 10(-5) M). The amplitude and frequency of contractions, motility index (MI) (amplitude × frequency), and area under the curve during the dose-response period were recorded. The primary outcome was the motility index. Data were analyzed using linear regression models.
We performed 130 experiments in myometrial strips obtained from 46 women. The overall MI (√gram·contractions·10 min(-1) [√g·c·10 min(-1)]) was greatest for oxytocin (mean 5.10 √g·c·10 min(-1); 95% confidence interval [CI] 4.70 to 5.50) than for ergonovine (mean 3.46 √g·c·10 min(-1); 95% CI 3.13 to 3.80; P < 0.001), PGF2α (mean 2.64 √g·c·10 min(-1); 95% CI 2.40 to 2.87; P < 0.001), and misoprostol (2.52 √g·c·10 min(-1); 95% CI 2.22 to 2.82; P < 0.001). The MI for oxytocin was significantly lower in augmented labour (mean 4.11 √g·c·10 min(-1); 95% CI 3.48 to 4.73) than in non-augmented labour (mean 5.19 √g·c·10 min(-1); 95% CI 4.39 to 6.00; P = 0.04) or in absence of labour (mean 5.80 √g·c·10 min(-1); 95% CI 5.36 to 6.24; P < 0.001). Nevertheless, in augmented labour, oxytocin still produced superior contractions compared with other uterotonic drugs. Responses to ergonovine, PGF2α, and misoprostol were unaffected by labour or prior exposure to oxytocin.
Oxytocin induces superior myometrial contractions compared with ergonovine, PGF2α, and misoprostol. The effect of oxytocin is reduced in myometrium of women with oxytocin-augmented labour; however, it is still superior to the other uterotonics. This trial was registered at ClinicalTrials.gov: NCT01689311.
比较非临产和临产孕妇离体子宫肌层对缩宫素、麦角新碱、前列腺素F2α（PGF2α）和米索前列醇的体外收缩反应。
从接受剖宫产的临产（使用或未使用缩宫素加强宫缩）和非临产妇女获取子宫肌条，用缩宫素、麦角新碱、PGF2α或米索前列醇（10⁻¹⁰ M至10⁻⁵ M）进行剂量反应测试。记录收缩的幅度和频率、运动指数（MI）（幅度×频率）以及剂量反应期的曲线下面积。主要结局指标是运动指数。使用线性回归模型分析数据。
我们对从46名妇女获取的子宫肌条进行了130次实验。缩宫素的总体MI（√克·收缩·10分钟⁻¹ [√克·次·10分钟⁻¹]）（平均5.10 √克·次·10分钟⁻¹；95%置信区间[CI] 4.70至5.50）大于麦角新碱（平均3.46 √克·次·10分钟⁻¹；95% CI 3.13至3.80；P < 0.001）、PGF2α（平均2.64 √克·次·10分钟⁻¹；95% CI 2.40至2.87；P < 0.001）和米索前列醇（2.52 √克·次·10分钟⁻¹；95% CI 2.22至2.82；P < 0.001）。在使用缩宫素加强宫缩的临产妇女中，缩宫素的MI（平均4.11 √克·次·10分钟⁻¹；95% CI 3.48至4.73）显著低于未使用缩宫素加强宫缩的临产妇女（平均5.19 √克·次·10分钟⁻¹；95% CI 4.39至6.00；P = 0.04）或未临产妇女（平均5.80 √克·次·10分钟⁻¹；95% CI 5.36至6.24；P < 0.001）。然而，在使用缩宫素加强宫缩的临产妇女中，缩宫素产生的宫缩仍优于其他宫缩剂。对麦角新碱、PGF2α和米索前列醇的反应不受临产或先前使用缩宫素的影响。
与麦角新碱、PGF2α和米索前列醇相比，缩宫素能诱导更优的子宫肌层收缩。在使用缩宫素加强宫缩的妇女的子宫肌层中，缩宫素的作用减弱；然而，它仍优于其他宫缩剂。本试验在ClinicalTrials.gov注册：NCT01689311。
