麦角新碱联合卡贝缩宫素与单用缩宫素预防剖宫产产后出血研究

目的比较麦角新碱联合卡贝缩宫素与单用缩宫素预防剖宫产产后出血的效果。方法采用真实世界研究方法,回顾性分析四川大学华西第二医院2017年1—12月收治的择期剖宫产孕妇424例。根据胎儿娩出后用药情况分为两组:给予麦角新碱联合卡贝缩宫素为研究组(208例),单用缩宫素为对照组(216例)。结果研究组术中额外用药率为2.4%,明显低于对照组22.2%,差异有统计学意义(P0.05)。研究组手术前后血红蛋白及红细胞压积分别为(126.9±9.9)g/L、(123.1±10.9)g/L及0.38±0.03、0.37±0.03,对照组分别为(126.6±12.1)g/L、(123.9±14.3)g/L及0.38±0.03、0.37±0.04,两组比较差异均无统计学意义(P0.05)。两组孕产妇失血量及按照单一合并症及并发症(妊娠期肝内胆汁淤积症、胎膜早破、妊娠期糖尿病、瘢痕子宫、胎盘粘连)估计失血量,两组比较差异均无统计学意义(P0.05);而严重产后出血率(出血量大于1000m L)研究组为1.4%,对照组为3.2%,两组之间的差异有统计学意义(P0.05)。结论麦角新碱联合卡贝缩宫素预防剖宫产严重产后出血及减少术中额外使用宫缩剂的效果较显著。     

缩宫素在引产与催产中的应用

缩宫素用于引产和催产在指征、剂量、时机和母儿监护等方面尚存不一致。正确认识缩宫素作用特点,注意不断调整用量,以期达到诱发有效宫缩、使产程正常进展而所用剂量最小,是保证其安全有效应用的关键。     

缩宫素在产程中的应用

缩宫素为一种多肽激素，自20世纪50年代合成纯化的缩宫素后，一直被广泛应用于临床，其主要作用机制为促进子宫平滑肌收缩。子宫对缩宫素的敏感性与子宫肌组织中缩宫素受体含量有关，个体差异较大，在产程中如使用得当则安全有效，可起到减少难产率及剖宫产率的作用；反之，可危及母儿生命。     

围产期用药的药理特点

1　胎儿药理1.1　药物吸收　药物进入胎儿体内的途径主要是通过胎盘 ,也有一些药物经羊膜腔转运进入羊水后而被胎儿吞饮 ,由胃肠道吸收入胎儿体内。从胎儿尿中排出的药物又可由胎儿吞饮羊水 ,重新进入胎体 ,形成羊水—肠道循环。现已证明 ,胎儿每小时吞噬羊水 5～ 70 ml不等。此外 ,胎儿皮肤也可从羊水中吸收药物。1.2　药物分布　药物在胎儿体内分布与胎儿血循环分配一致 ,胎儿的肝、脑相对较大 ,血液灌注量大 ,血液通过脐静脉 ,大部分 (约 6 0 % )经肝脏至心脏 ,而其余 (40 % )中的相当大部分至胎儿脑。因而药物分布至肝、脑较多。缺氧时 …     

缩宫素对神经精神系统发育的影响

缩宫素（oxytocin,OT）在分娩和泌乳中起重要作用,近年OT对神经精神系统发育的影响逐渐受到重视。分娩时主要来源于母体下丘脑的OT通过减少神经元活动及代谢的能量需求,对分娩过程中的胎脑起保护作用。OT同时作为神经递质或神经调质,调节儿童神经精神系统发育,并可能与儿童孤独症、成人社会行为、社会认知障碍相关。研究OT对神经精神系统发育的影响有重要意义。     

缩宫素对神经精神系统发育的影响

缩宫素（oxytocin, OT）在分娩和泌乳中起重要作用,近年OT对神经精神系统发育的影响逐渐受到重视。分娩时主要来源于母体下丘脑的OT通过减少神经元活动及代谢的能量需求,对分娩过程中的胎脑起保护作用。OT同时作为神经递质或神经调质,调节儿童神经精神系统发育,并可能与儿童孤独症、成人社会行为、社会认知障碍相关。研究OT对神经精神系统发育的影响有重要意义。     

缩宫素与前列腺素在足月妊娠引产中的比较

由于足月妊娠母婴合并症及并发症需终止妊娠或临产后因宫缩欠佳需加强产力时,传统方法多采用缩宫素引产或促产;近年来临床上已开始使用前列腺素类药物来促宫颈成熟和足月妊娠引产,临床医师在选择这两种药物时应对其作用机理、使用方法、副反应及注意事项有充分了解和比较,以便更好发挥药效,减少副反应。1　理化作用1.1　缩宫素(Oxytocin.OT)妊娠期OT主要由母体下丘脑视上核及室旁核合成,分娩时宫内OT的增加来源于蜕膜、绒毛膜、羊膜上缩宫素基因的表达。多种因素可促OT的释放,如分娩中胎头刺激宫颈、阴道上段的感受器;而儿茶酚胺类药物…     

缩宫素在催引产中的规范化应用

缩宫素是目前临床上应用最广泛的催产、引产药物,在有效缩短分娩时间及降低剖宫产率方面发挥着不可替代的作用。但缩宫素的不规范使用也会增加母儿并发症的发生率。临床实践中对于缩宫素的使用剂量、方法、时机以及活跃期是否停用等方面尚未达成一致。因此,寻找缩宫素的最佳用药剂量、把握用药时机、合理规范使用的同时避免不规范使用带来的严重不良结局,是保障用药安全及成功经阴道分娩的关键。     

地塞米松辅助缩宫素预防产后出血的初探

本文对100例因胎儿偏大、臀位及骨盆等因素而行剖官产术的足月产妇，在剖官产术中胎儿娩出后静推地塞米松及催产素，发现术后2h内失血量较单用催产素明显减少。现报道如下。     

对引产中缩宫素使用持续时间的探讨

本研究目的是探讨引产过程中 ,在宫缩活跃后是否需要继续使用缩宫素。作者前瞻性观察使用缩宫素引产的 10 4例孕妇 ,引产的指征为 :①过期妊娠 ;②胎膜早破超过 2 4小时 ;③羊水过少 ,羊水指数小于 5cm ;④胎儿生长受限 (FGR) ;⑤孕妇糖尿病 ;⑥散发的胎心监护不满意。病例排除标准为 :①胎儿非纵产式 ;②超过 1次的剖宫产史 ;③多胎妊娠 ;④频发的胎心监护不满意 ;⑤B超估计胎儿体重超过 4 2 5 0g。随机分为两组 ,每组各有 5 2例孕妇。A组孕妇缩宫素逐渐加量诱导宫缩 ,至宫口开大 5cm时维持该浓度直至分娩 ;B组孕妇缩宫素逐渐加量 ,到宫…     

Pharmacology of oxytocin and prostaglandins

Significant advances have been made in the last 20 years in our knowledge about the subcellular events occurring during myometrial contractions and cervical ripening and in the mechanism of action of oxytocin and prostaglandins. These advances have been instrumental in furthering our understanding of the mechanism of action of inhibitors of uterine contractility and have opened the door to clinical trials of agents such as specific COX-II inhibitors that may have the potential to inhibit labor without serious maternal or fetal side effects. There is still a long way to go, however, before all the complex actions of oxytocin and prostaglandins can be understood at a subcellular level, particularly the mechanism of action of prostaglandins in the process of cervical ripening.     

The effect of labour and maternal oxytocin infusion on fetal plasma oxytocin concentration

It is not known whether human labour is associated with increased fetal oxytocin production or transfer of oxytocin across the placenta. Previous reports are contradictory, due in part, to the influence of maternal analgesia on fetal production. We determined plasma oxytocin concentration in the umbilical artery and vein of women after vaginal delivery and after caesarean section with general anaesthesia before or after the onset of labour. The results demonstrate that fetal production of oxytocin is not influenced by general anaesthesia, thus enabling comparison of labour and nonlabour samples at caesarean section. Labour was not associated with an increase in fetal oxytocin production. Oxytocin was also measured in the umbilical artery and vein during maternal oxytocin infusion to assess placental transfer. The results do not support transfer of oxytocin across the placenta in women.     

The effect of labour and maternal oxytocin infusion on fetal plasma oxytocin concentration

It is not known whether human labour is associated with increased fetal oxytocin production or transfer of oxytocin across the placenta. Previous reports are contradictory, due in part, to the influence of maternal analgesia on fetal production. We determined plasma oxytocin concentration in the umbilical artery and vein of women after vaginal delivery and after caesarean section with general anaesthesia before or after the onset of labour. The results demonstrate that fetal production of oxytocin is not influenced by general anaesthesia, thus enabling comparison of labour and nonlabour samples at caesarean section. Labour was not associated with an increase in fetal oxytocin production. Oxytocin was also measured in the umbilical artery and vein during maternal oxytocin infusion to assess placental transfer. The results do not support transfer of oxytocin across the placenta in women.     

Comparison of oxytocin and oxytocin antagonist metabolism in the plasma of pregnant humans and baboons

Oxytocin antagonists may be useful in inhibiting the uterine contractions of preterm labor. One such compound is TT-235 (previously referred to as Antag III). The purpose of this study was to compare the resistance of TT-235 and oxytocin to enzymatic degradation by oxytocinase in the blood of humans and baboons during their 3rd trimester of pregnancy. Blood samples from pregnant women and baboons not in labor were incubated in vitro with known amounts of oxytocin and TT-235. Samples were collected at 0, 15, 30, 45, and 60 min for oxytocin analysis and at 0, 10, 60, and 360 min for TT-235 analysis. Oxytocin was analyzed by radioimmunoassay after extraction, while TT-235 was analyzed by radioreceptor assay. In human blood, oxytocin was readily metabolized with >83% disappearance over the 60-min incubation period. In contrast, TT-235 was stable up to 360 min of incubation. In the baboon, oxytocin did not diminish over the 60-min incubation period. The level of TT-235 was similar to that in human blood without change over 360 min of incubation. This study suggests (1) that in contrast to blood from pregnant humans, blood from pregnant baboons lacks oxytocinase at least in vitro and (2) that TT-235 is resistant to enzymatic degradation by human blood, implying that this oxytocin antagonist may have a prolonged activity in vivo in humans.     

Induction of labor with vaginal misoprostol plus oxytocin versus oxytocin alone

Objective

To compare the effect of an oxytocin infusion alone or preceded by an intravaginal application of misoprostol for labor induction in women with term pregnancies and a low Bishop score.

Methods

This study randomized 100 multiparous women with singleton pregnancies over 38 weeks and a Bishop score less than 6 to receive either a single 50-µg dose of misoprostol intravaginally 3 hours before initiation of the oxytocin infusion or only an oxytocin infusion. The time from induction to delivery, the route of delivery, and maternal and fetal outcomes were analyzed.

Results

The mean time from induction to delivery was 9.36 ± 1.97 hours in the misoprostol plus oxytocin group and 11.08 ± 3.23 in the oxytocin alone group (P = 0.002). The rates of vaginal delivery, 1- and 5-minute Agpar scores, placental abruption, and postpartum hemorrhage were similar between the 2 groups, as were the rates of admission to the neonatal intensive care unit. There were no cases of perinatal asphyxia.

Conclusion

A 50-µg intravaginal application of misoprostol before starting the oxytocin infusion is a more effective method of labor induction than an oxytocin infusion alone for our study population.     

Human ovulation and plasma oxytocin

Plasma oxytocin (OT) concentrations were measured by radioimmunoassay (RIA) method without extracting plasma in 11 normal menstruating women. Mean plasma OT level began to increase steadily from the 7th day of the menstrual cycle and this level rose up to 20 +/- 5 microU/ml (Mean +/- S.E.) on the 10th day of the cycle. OT level declined to 13 +/- 6 microU/ml on the day of LH peak and continuously declined for another 2 days - then rose. The OT level was higher during the follicular phase than during the luteal phase. In 1 individual OT measured in 2 cycles a year apart showed the highest level of OT coincided with LH and FSH peak and abruptly declined. When there was the highest level of progesterone, the OT level was measurable 1 out of 11 cycles. From this study, we conclude that OT may have a role in human ovulation either synergistically or alone with other ovulatory mechanisms and ovarian estradiol and progesterone control the secretion of OT and also suggests that OT may play some role in the regulation of the luteolysis and the menstrual cycle in women.