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The analgesic efficacy of remifentanil for labour. Systematic review of the recent literature.

BACKGROUND AND AIMS
Although epidural analgesia is still regarded as the gold standard for labour analgesia due to its efficacy, in cases of contraindication, systemic remifentanil is an alternative. Since the first demonstration of the safety of remifentanil in obstetric analgesia in 1996, this has been repeatedly confirmed for both mother and newborn. The aim of this meta-analysis is to evaluate recently published studies (up to December 2014) on the analgesic efficacy of remifentanil during labour (as a Visual Analogue Scale (VAS) decrease in the first hour by 2 or more).


METHODS
Search of the US National Library of Medicine, National Institutes of Health (www.pubmed.gov), SCOPUS database (www.scopus.com) and Web of Science database (www.webofknowledge.com) using the key words "labour" and "remifentanil". 44 identified articles were included in the review and 15 published randomised controlled studies were incorporated into the meta-analysis. This was based on the fixed model and described by differences in the VAS between t=0 and t=1 hour after remifentanil administration using the 95% confidence interval (CI). The analysis was computed using the Comprehensive meta-analysis version 2.2.064.


RESULTS
The combined data from the meta-analysis showed a statistically significant decrease in VAS in the remifentanil group. From a comparison of the CIs of summary estimates with a cut-off decrease of VAS 2, for the fixed model, there was a statistically significantly greater decrease in VAS than the cut-off. In the systematic review, we describe possible modes of application, dosage and side-effects for mother, fetus/ newborn.


CONCLUSION
The meta-analysis presented here confirms that remifentanil for labour analgesia is effective but questions remain which can only be answered by further randomized trials.