The effect of maternal low flow oxygen administration during the second stage of labour on umbilical cord artery pH : a randomised controlled trial

作者：Guangfang Qian, Xiaobin Xu, L Chen, Songyun Xia, A Wang, Yunhai Chuai, Wen Jiang · 发表于：BJOG An International Journal of Obstetrics & Gynaecology · 年份：2017 · DOI：10.1111/1471-0528.14418 · 被引用次数：30 · 研究领域：Neonatal and fetal brain pathology、Neonatal Respiratory Health Research、Pregnancy and preeclampsia studies

OBJECTIVE: To assess the effect of maternal low flow oxygen administration during the second stage of labour on umbilical cord artery pH. DESIGN: A randomised controlled trial. SETTING: A tertiary teaching hospital in China. POPULATION: Women in the second stage of labour with no complications. METHODS: About 443 women were randomly allocated to receive either supplemental oxygen at a flow rate of 2 l/min or a sham supplementation by nasal cannula. Healthcare providers, women and outcome assessors were blinded to allocation. MAIN OUTCOME MEASURES: Umbilical cord artery pH and fetal heart rate (FHR) pattern. RESULTS: Baseline characteristics were similar between the two groups. There were no significant differences between the two groups in the umbilical cord artery pH [median 7.261, interquartile range (IQR) 7.228-7.295 versus 7.266 (IQR 7.232-7.297), P = 0.64], the proportion with pH less than 7.2 [30/219 versus 34/224, P = 0.66, RR (relative risk) 0.9, 95% CI 0.57-1.42], and the proportion with normal FHR pattern (147/219 versus 153/224, P = 0.79, RR 0.98, 95% CI 0.86-1.12). Maternal partial pressure of dissolved oxygen was significantly higher in the oxygen group than in the sham group [median 150.0 mmHg (IQR 142.6-156.7) versus 112.0 (IQR 104.8-118.3), P < 0.001], whereas carbon dioxide was significantly lower in the oxygen group than in the sham group (mean difference -1.1, 95% CI -2.1 to -0.1, P = 0.03). CONCLUSION: The use of 2 l/min maternal oxygen during the second s...