Remifentanil for labour analgesia: a meta-analysis of randomised controlled trials.

CONTEXT Remifentanil is a potent short-acting μ-opioid receptor agonist which is rapidly metabolised in the mother and fetus and may be ideal for labour analgesia. OBJECTIVES To assess efficacy and safety of remifentanil compared with other analgesic techniques for labour pain. DATA SOURCES We systematically searched the central register of controlled trials of the Cochrane Library (till August 2011) and MEDLINE (till August 2011). ELIGIBILITY CRITERIA Randomised controlled trials investigating efficacy and safety of remifentanil administered via a patient-controlled analgesia (PCA) device compared with any other analgesic technique for labour pain were included. RESULTS We finally included 12 randomised controlled trials (published from 2001 to 2011). Women treated with remifentanil had a lower risk of conversion to epidural analgesia (P < 0.001), a lower mean pain score after 1 h (P < 0.001) and had higher satisfaction scores (P < 0.05) in comparison with women receiving pethidine. Epidural analgesia decreased pain scores compared with remifentanil (P = 0.003). There was only a limited amount of data comparing remifentanil with nitrous oxide or fentanyl. Serious maternal or fetal adverse outcomes were not reported in these trials. CONCLUSION During labour, remifentanil-PCA provided superior analgesia and higher patient satisfaction compared with pethidine with a comparable degree of adverse events. Epidural analgesia provided superior pain relief in comparison with remifentanil. Due to a low number of reported adverse events, the safety issue of remifentanil use in labour remains an open question that needs to be addressed in future trials.