硫酸镁作为子宫松弛剂的应用

硫酸镁抑制宫缩治疗早产有较好的疗效。大剂量硫酸镁能降低胎盘血管阻力,增加子宫动脉血流量,对胎儿有利。高浓度的硫酸镁使神经肌肉连接处减少神经冲动所释放的乙酰胆硷,降低终板对其敏感性。镁离子在细胞内与钙离子竞争,使其浓度下降,肌球蛋白轻链激酶不能活化而抑制平滑肌收缩,达到松弛目的。硫酸镁保胎时副反应发生率低,减慢用药速度即缓解,其严重副反应有肺水肿,但发生率较肾上腺素能β受体兴奋剂少。     

宫缩抑制剂预防早产的药物评价研究进展

各种宫缩抑制剂在临床上早已广泛应用于预防早产,宫缩抑制剂有β2受体激动剂、硫酸镁、钙通道阻滞剂和缩宫素受体拮抗剂等类型.而日益增多的研究证据表明,由于β2受体激动剂的药物不良反应,全世界范围正在逐渐减少β2受体激动剂的使用;硫酸镁仍是美国最常用的宫缩抑制剂,最近发现对于早产儿具有神经保护作用;钙通道阻滞剂治疗早产在近几年受到了大量的关注,在治疗早产上比β2受体激动剂更有效,也更安全;缩宫素受体拮抗剂阿托西班具有很好的孕妇和胎儿安全性,其疗效仍有待进一步证实.     

阿托西班在晚期流产和早产治疗中的临床价值

目的 探讨缩宫素受体拮抗剂--阿托西班在晚期流产和早产治疗中的临床价值.方法 对应用B2受体激动剂--利托君、硫酸镁后子宫收缩仍不能被抑制、产程仍然进展、或出现不良反应的35例晚期流产和早产患者,应用阿托西班短期用药方案进行治疗,观察阿托西班抑制宫缩的疗效、药物不良反应和妊娠结局.结果 应用阿托西班48 h时抑制宫缩的有效率为77%(27/35),7 d时抑制宫缩的有效率为60%(21/35).1例(3%)出现轻微恶心和呕吐反应.35例患者中分娩34例,1例双胎妊娠在随访中.34例已分娩患者中,孕周＜28周分娩11例,28～34周分娩17例,＞34周分娩3例,足月分娩3例.应用阿托西班后妊娠时间最短延长4 h,最长延长14周+2.新生儿存活34例,死亡9例(孕周均＜28周),34个存活新生儿中发生新生儿呼吸窘迫综合征14例.结论 对早产或晚期流产患者应用利托君、硫酸镁治疗无效或出现不良反应时,阿托西班仍有明显延长妊娠时间的作用,且患者的妊娠结局良好.     

盐酸利托君与硫酸镁治疗先兆早产的Meta分析

目的:评价盐酸利托君与硫酸镁治疗先兆早产的效果与副反应,以阐明两种药物的临床应用价值。方法:计算机检索相关数据库,收集盐酸利托君与硫酸镁治疗先兆早产的随机对照试验,对符合纳入标准的临床研究进行Meta分析。结果:共纳入34篇文献,盐酸利托君较硫酸镁起效快,延长妊娠时间,增加新生儿体重,但孕妇副反应发生率较高。与硫酸镁组相比,盐酸利托君组显效时间、延长妊娠时间及新生儿出生体重的MD值(95%CI)分别为-1.22(-1.24,-1.20)、0.97(0.87,1.06)、0.39(0.36,0.41),副反应的OR值为2.21(95%CI 1.89,2.59)。结论:盐酸利托君治疗先兆早产的显效时间短、延长妊娠时间较长,且新生儿出生体重等均较硫酸镁好,但其母体发生副反应的风险明显高于硫酸镁。如何安全有效地选择保胎药物还需要进一步分层随机对照研究来证实。     

安宝治疗产时胎儿窘迫40例临床分析

目的探讨安宝治疗产时胎儿窘迫效果.方法对40例诊断为产时胎儿窘迫并准备行剖宫产终止妊娠的病例作为研究组,术前给予安宝治疗;并随机选择40例符合相同条件的病例作为对照组.观察治疗后产妇的心率变化、宫缩抑制情况、异常胎监图形恢复情况、新生儿出生后Apgar评分和脐静脉血pH.结果应用安宝后产妇虽有心率加速,但无一例＞130/min,无一例自诉不适;用药后宫缩显著抑制(P＜0.01);异常胎监图形明显恢复(P＜0.01);新生儿窒息发生率显著低于对照组(P＜0.05),新生儿出生后1分钟Apgar评分显著高于对照组(P＜0.05);脐静脉血pH虽高于对照组,但无统计学差异,估计与例数偏少有关.结论安宝通过有效抑制宫缩、改善子宫-胎盘血流灌注,对于产时胎儿窘迫者用药是安全、有效的.     

安宝治疗前时胎儿窘迫40例临床分析

目的 探讨安宝治疗产时胎儿窘迫效果。方法 对４０例诊断为产时胎儿窘迫并准备行剖宫产终止妊娠的病例作为研究组,术前给予安宝治疗;并随机选择４０例符合相同条件的病例作对照组。观察治疗后产妇的心率变化、宫缩抑制情况、异常胎监图形恢复情况、新生儿出生后Ａｐｇａｒ评分和脐静脉血ｐＨ。结果 应用安宝后产妇虽有心率加速,但无一例〉１３０／ｍｉｎ,无一例自诉不适;用药后宫缩显著抑制（Ｐ〈０．０１）;异常胎监图形明显恢复（Ｐ〈０．０１）;新生儿窒息发生率显著低于对照组（Ｐ〈０．０５）,新生儿出生后１分钟Ａｐｇａｒ评分显著高于对照组（Ｐ〈０．０５）;脐静脉血ｐＨ虽高于对照组,但无统计学差异,估计与例数偏少有关。结论 安宝通过有效抑制宫缩、改善子宫－胎盘血流灌注,对于产时胎儿窘迫者用药是安全、有效的。     

早产药物治疗的循证评价

<正>中华医学会妇产科学分会颁布早产指南中明确提出治疗或预防早产的药物有四类,包括宫缩抑制剂、硫酸镁、产前糖皮质激素和预防性地应用抗生素。此外,最新有文献报道另有其他药物对早产保胎有一定疗效,本文就这些药物对早产预防和治疗进行循证医学分析与评价。1 宫缩抑制剂宫缩抑制剂包括β2-肾上腺素能受体兴奋剂、缩宫素受体拮抗剂、钙离子通道阻滞剂和前列腺素合成酶抑制剂。1.1 β2-肾上腺素能受体兴奋剂β2-肾上腺素能受体兴奋剂通过与β2     

早产的药物治疗及评价

1　抑制早产治疗的禁忌证在以下情况不应进行宫缩抑制治疗 :①胎儿已死 ;②胎儿有影响生存的重大畸形 ;③宫内感染 ;④孕妇有严重的妊娠合并症 ,需要及早分娩时 ;⑤胎儿可存活。2　早产的一般治疗早产患者需取侧卧位 ,卧床休息。休息后宫缩可减少。理论上认为静脉补液治疗可通过增加子宫的血流 ,降低垂体抗利尿激素和催产素的分泌 ,起到抑制宫缩的作用。通常是静脉给予 5 0 0ｍＬ的生理盐水或乳酸林格液。最近Ｓｔａｎ等荟萃分析的结果发现 :静脉补液治疗与卧床休息比较并没有明显优越之处[1] 。3　抑制宫缩的药物目前抑制宫缩的药物有以下 …     

催产素受体拮抗剂治疗早产的研究进展

目前治疗早产抑制宫缩的药物已不少 ,如 β2 肾上腺素能受体激动剂、钙离子通道阻滞剂、硫酸镁、前列腺素抑制剂等 ,然而在有效性与安全性方面尚未令人满意。近年来 ,一种抑制宫缩的新药———催产素受体拮抗剂 (Ａｔｏｓｉｂａｎ)已完成Ⅲ期临床试验 ,并被证实是一种有效的、副反应较少的、具有广泛临床应用前景的治疗早产药物。1　催产素在分娩发动中的作用正常分娩发动机制尚不明确。分娩发动过程主要包括子宫有效收缩和宫颈成熟扩张。许多研究表明 ,分娩发动过程的主要效力因子分别是催产素和前列腺素 ,它们相互影响 ,协同作用[1] 。子…     

苄羟麻黄碱治疗早产的临床观察

目的：探讨β２－肾上腺素能受体兴奋剂苄羟麻黄碱抑制子宫收缩，治疗早产的临床效果。方法：对１２６例先兆早产孕妇随机分为两组，分别静脉滴注苄羟麻黄碱或硫酸镁。采用达到有效抑制宫缩的最低浓度，适时停药，病情反复则间歇多次应用。结果：苄羟麻黄碱首次用药达有效抑制宫缩的显效时间为２．３３±０．６３小时，用药总累计时间为９．３８±３．８８天；延长孕期４．８１±２．８３周；足月分娩率７３．４４％；均极显著优于硫酸镁组（Ｐ分别＜０．００１、０．００５、０．０１）。尚未发现严重毒副反应。结论：苄羟麻黄碱抑制宫缩作用强、显效快，治疗早产安全、有效     

Magnesium sulfate as a tocolytic agent

Although magnesium sulfate is widely used as a tocolytic agent in the hope of preventing spontaneous preterm birth, there is a paucity of data from large well-designed randomized clinical studies demonstrating the efficacy of magnesium sulfate therapy. Given the potential for untoward side effects and the inherent risks of magnesium sulfate therapy, a thorough understanding of the potential risks and benefits of this agent is needed. To accomplish this understanding we have provided a detailed review the history, pharmacology, physiology, maternal/fetal side effects, and tocolytic efficacy of magnesium sulfate.     

Oral nicardipine versus intravenous magnesium sulfate for the treatment of preterm labor

OBJECTIVE: The aim of this study was to compare the efficacy and safety of oral nicardipine in acute therapy for preterm labor with those of parenteral magnesium sulfate. STUDY DESIGN: Patients between 24 and 34 weeks' gestation with documented preterm labor were randomly assigned to receive oral nicardipine (n = 57) or intravenous magnesium sulfate (n = 65) as initial tocolytic therapy. Patients in the nicardipine group received a 40-mg loading dose and then 20 mg every 2 hours as needed to stop contractions (total 80 mg). Patients in the magnesium sulfate group received a 6-g bolus followed by 2 to 4 g/h to provide uterine quiescence. Patients could be switched to another tocolytic regimen if they continued to have contractions after 6 hours of therapy. The main outcome variables examined were time to uterine quiescence, time gained in utero, recurrence of preterm labor, failure of tocolysis, and pertinent maternal and neonatal outcomes. RESULTS: There were no significant differences in maternal demographic characteristics between the groups. Among patients who responded with uterine quiescence within 6 hours, there was a significant decrease in the time to uterine quiescence in the nicardipine group (P <.01). Patients in the magnesium sulfate group were more likely to have recurrence of preterm labor necessitating further tocolytic attempts (P =.048). The patients in the magnesium sulfate group had more adverse side effects, mainly nausea and vomiting (P =.004). There were no differences in birth weight, estimated gestational age at delivery, or neonatal complications between the 2 groups. CONCLUSIONS: Oral nicardipine is an effective, safe, and well-tolerated tocolytic agent. In this prospective clinical trial patients randomly assigned to receive oral nicardipine had arrest of preterm labor more rapidly than did those randomly assigned to receive parenteral magnesium sulfate. Patients who received magnesium sulfate were more likely to have adverse medication effects and recurrent preterm labor.     

Prevention of preterm delivery: nifedipine or magnesium sulfate.

OBJECTIVE: to establish the efficacy and safety of nifedipine and magnesium sulfate in arresting preterm labor. METHOD: seventy-four patients with singleton pregnancies at 23-36 weeks in preterm labor, were selected randomly to receive either oral nifedipine or intravenous magnesium sulfate. RESULTS: both drugs had similar tocolytic efficacy and side effects while nifedipine was faster than magnesium sulfate in arresting uterine contractions (4.8 +/- 4.23 vs. 2.98 +/- 3.03 h) P = 0.04. CONCLUSION: this data suggests that oral nifedipine with the same efficacy, side effects and faster action could be a suitable and more convenient alternative to intravenous magnesium sulfate in arresting preterm labor.     

The effect of magnesium sulfate tocolysis on the fetal biophysical profile

The biophysical profile has proved to be a valuable tool for the assessment of fetal well-being, independent of gestational age. Magnesium sulfate is commonly used as a tocolytic agent, yet relatively little is known about its effects on the biophysical activities of the fetus. To investigate the effects of magnesium sulfate on the biophysical profile, we performed serial studies on patients who received tocolytic therapy with this agent because of preterm labor. A total of 16 women with 22 fetuses at 26 to 34 weeks' gestation in spontaneous preterm labor were studied. An initial biophysical profile was performed at the time of admission, and a second examination was performed when maternal serum magnesium levels reached 6 to 8 mg/dl. On admission all fetuses had reactive nonstress test results and 21 of 22 (95%) demonstrated sustained fetal breathing movements. With magnesium sulfate tocolysis, 50% of fetuses had nonreactive nonstress test results, and only 4 of 22 (18%) demonstrated sustained fetal breathing movements. Fetal tone, gross body movements, and amniotic fluid volume were found to be unaffected by magnesium sulfate tocolysis.     

Magnesium sulfate tocolysis: time to quit

Intravenous magnesium sulfate tocolysis remains a North American anomaly. This therapy rose to prominence based on poor science and the recommendations of authorities. However, a Cochrane systematic review concluded that magnesium sulfate is ineffective as a tocolytic. The review found no benefit in preventing preterm or very preterm birth. Moreover, the risk of total pediatric mortality was significantly higher for infants exposed to magnesium sulfate (relative risk 2.8; 95% confidence interval 1.2-6.6). Given its lack of benefit, possible harms, and expense, magnesium sulfate should not be used for tocolysis. Any further use of magnesium sulfate for tocolysis should be restricted to formal clinical trials with approval by an institutional review board and signed informed consent for participants. Should tocolysis be desired, calcium channel blockers, such as nifedipine, seem preferable.     

Randomized investigation of magnesium sulfate for prevention of preterm birth

One hundred fifty-six women with preterm labor between 24 and 34 weeks' gestation were randomized to receive either intravenous magnesium sulfate or no tocolytic therapy. Magnesuim sulfate infusions of up to 3 gm/hr were used in 76 pregnancies and resulted in a mean serum magnesium concentration of 5.5 +/- 1.4 mEq/L (mean +/- SEM). Compared with 80 control pregnancies, magnesium sulfate tocolysis had no significant effect on duration of gestation, birth weight, neonatal morbidity, and perinatal mortality. We conclude that clinically safe infusions of magnesium sulfate are ineffective when used to prevent preterm birth.     

Efficiency and safety of magnesium sulfate treatment in obstetrics

Current views on efficacy and safety of magnesium sulfate treatment in obstetrics are presented. Negative effects of MgSO4 on fetus and newborn are described. Contradictory reports dealing with tocolytic efficacy of magnesium sulfate are discussed.     

The safety and efficacy of tocolytic agents for the treatment of preterm labor

Pharmacologic inhibition of uterine contractions remains the mainstay of treatment for preterm labor despite the ongoing controversy regarding its effectiveness. A diverse variety of tocolytic medications have been proposed for clinical use, with betamimetics and magnesium sulfate being the common therapeutic agents of choice in the United States today. The clinician using these agents should be aware of the significant maternal and fetal side-effects associated with these particular medications. New classes of pharmacologic agents, including prostaglandin synthetase inhibitors, calcium channel blockers and phosphodiesterase inhibitors, have been proposed as tocolytic agents and are currently undergoing critical clinical evaluation. The purpose of this review is to provide a compilation of the available clinical studies that document the safety and efficacy of these various tocolytic agents.     

Maternal paralytic ileus as a complication of magnesium sulfate tocolysis

Beta-adrenergic agonists tocolysis is currently the most popular treatment modality in the United States. However, magnesium sulfate is receiving increasing attention as an alternating tocolytic agent in the presence of various clinical situations, such as the treatment of insulin-dependent diabetes. While there is an abundance of information about the maternal and fetal side effects associated with beta-adrenergic tocolysis, little information is available about maternal adverse side effects of magnesium sulfate treatment for preterm labor. Side effects such as pulmonary edema, respiratory depression, hypocalcemia, and hypermagnesemia have been reported in patients receiving this agent for either tocolysis or pre-eclampsia, though their occurrence is quite rare. One of the infrequent complications of beta-adrenergic agonist tocolysis is the occurrence of a paralytic ileus, which to our knowledge has not yet been reported in association with magnesium sulfate tocolysis. This article therefore concerns the development of a paralytic ileus in a patient receiving parenteral magnesium sulfate for tocolysis. The clinical features are described and the possible mechanisms involved discussed.