氧化亚氮吸入分娩镇痛对产程中胎心率的影响

目的:探讨氧化亚氮吸入分娩镇痛对产程中胎心率的影响。方法:随机选择2003年8月~2004年6月分娩的足月、单胎、头位、无阴道分娩禁忌症且宫口扩张≥3cm的一对一专责助产士陪伴分娩的初产妇876例,以自愿接受氧化亚氮吸入分娩镇痛的438例作为研究组,未采用任何药物进行分娩镇痛的438例作为对照组,镇痛前、后监护胎心率直至胎儿娩出。结果:尽管两组间胎儿窘迫及新生儿窒息率无显著性差异,但研究组在产程活跃期胎心率加速减少,基线细变异减少,出现频发早期减速以及迟发减速者多于对照组。结论:使用氧化亚氮吸入分娩镇痛有必要密切监护胎心率的变化以及早发现胎儿缺氧,及时处理,避免胎儿窘迫和新生儿窒息。

Effects of inhalation of nitrous oxide in oxygen during the active of labour on fetal heart rate

Objective:To investigate the effects of inhalation of nitrous oxide during the active of labour on.fetal heart rate. Methods:Occiput presentation, term nulliparous without vaginal delivery contraindication were randomized enrolling in the study. 438 parturients were given 50% nitrous oxide in oxygen during the active of labour voluntarily. 438 parturients given no analgesic but a doula were randomized into compared group..Cardiotocography was performing continuously at least 20 min before analgesia, after the start of analgesia at 1st stage of labour and continue it until the 3rd stage of labour began. Results:After inhalating nitrous oxide FHR-baseline variability and acceleration becoming less or loss are significantly more frequent. Although fetal depress and neonatal asphyxia reached no statistical significance as compared with no labor analgesia, early deceleration and late deceleration appeared more frequently. Conclusion:The present data recommended caution when performing labour analgesia with nitrous oxide. It seems important that cardiotocography monitored continuously to detect fetal hypoxaemia after inhalating nitrous oxide.