Su Fangming, Wei Xiaoping, Chen Xiaohe, Hu Zhiyang, Xu Hongli
Department of Obstetrics, Second People's Hospital Affiliated to Jinan University, Shenzhen 518020, China.
Zhonghua Fu Chan Ke Za Zhi. 2002 Oct;37(10):584-7.
To investigate the efficacy and safety of labor analgesia with inhalation of 50% nitrous oxide in oxygen.
A total of 1300 cases of term primiparous women in labor were divided into two groups. Study group (n = 658) 50% nitrous oxide in oxygen was inhaled during labor for relieving labor pain. Control group (n = 642) intermittent inhalation of 50% oxygen was carried out during labor. Two groups were compared with following indices: duration of the labor, delivery mode, meconium stained of amniotic fluid, postpartum bleeding volume, neonatal Apgar score, side effect of nitrous oxide, and blood gas analysis of samples from maternal radius artery and fetal umbilical blood.
The efficiency of relieving labor pain in study group was much better than that of control group (80.9% vs 0.9%, P < 0.001). Rate of cesarean section in study group was lower than control group (11.6% vs 19.3%, P < 0.05). The active phase of labor in study group was shorter than control group (153 min vs 187 min, P < 0.05). There was side effect of dizziness in 39.4% cases of study group but there were no any complaint in the control group cases. There were no significantly differences in duration of the labor, meconium stained amniotic fluid, postpartum bleeding volume, neonatal Apgar score, and blood gas analysis between two groups (P > 0.05).
Inhalation of 50% nitrous oxide in oxygen was safe and effective labor analgesia. It is acceptable. The measure of relieving labor pain may increase the vaginal birth rate. There is no severe side effect on mother and baby.
探讨吸入含50%氧化亚氮的氧气用于分娩镇痛的有效性及安全性。
将1300例足月初产妇分为两组。研究组（n = 658）在分娩过程中吸入含50%氧化亚氮的氧气以减轻分娩疼痛。对照组（n = 642）在分娩过程中间歇吸入50%的氧气。比较两组的以下指标：产程、分娩方式、羊水粪染情况、产后出血量、新生儿Apgar评分、氧化亚氮的副作用以及产妇桡动脉和胎儿脐血样本的血气分析。
研究组分娩镇痛有效率明显优于对照组（80.9%对0.9%，P < 0.001）。研究组剖宫产率低于对照组（11.6%对19.3%，P < 0.05）。研究组活跃期产程短于对照组（153分钟对187分钟，P < 0.05）。研究组39.4%的病例出现头晕副作用，而对照组病例无任何不适主诉。两组在产程、羊水粪染情况、产后出血量、新生儿Apgar评分及血气分析方面差异无统计学意义（P > 0.05）。
吸入含50%氧化亚氮的氧气是一种安全有效的分娩镇痛方法，是可接受的。这种减轻分娩疼痛的措施可能会提高阴道分娩率。对母婴无严重副作用。
