Effectiveness of remifentanil for labor pain control: A systematic review and meta-analysis

Background: Many medical conditions restrict the use of neuraxial analgesia for labor pain control, and several options such as hypnosis, acupuncture, entonox and doula have limited efficacy. Intravenous remifentanil patient-controlled analgesia (PCA) is being considered as the potential alternative to epidural analgesia (EA) and assessed by several studies. The aim of this study was to systematically assess the effectiveness of intravenous remifentanil patient-controlled analgesia (PCA) for the relief of labor pain and the influence on maternal and infant outcomes. Methods: Electric databases and clinical guidelines were searched. Two reviewers independently evaluated the relevance, inclusion and study quality, and extracted the data of randomized controlled trials in which i.v. remifentanil PCA were compared with any other analgesic treatment for labor pain in healthy parturients. Weighted mean differences and odds ratio were calculated and are reported with 95% confidence intervals. Results: From 75 potentially relevant titles and abstracts, five studies, of variable methodological quality, were included. All included trials used i.v. remifentanil PCA technique and compared with different pain-alleviating means, examining analgesic efficacy from 30 min to over 11 h. Remifentanil provided superior analgesic effect than the comparison (weighted mean difference -1.85, 95% confidence interval -2.17 to -1.54), but produced negative influence on the infant outcomes (Odds Ratio 0.10, 95% confidence interval 0.03 to 0.42). Delivery methods and side effects were similar between remifentanil and the comparison. Conclusions: Pooled assessment of remifentanil intervention seems an attractive strategy for controlling labor pain in health term parturients, but it is not supported by strong evidence. Current evidence suggests that it may produce effective analgesia by only a modest level.