Epidural Analgesia with Amide Local Anesthetics, Bupivacaine, and Ropivacaine in Combination with Fentanyl for Labor Pain Relief: A Meta-Analysis

Background: The study compares the effectiveness of bupivacaine and fentanyl (BUPI-FEN) and ropivacaine and fentanyl (ROPI-EFN) in epidural analgesia for labor pain through a meta-analysis of relevant randomized clinical trials.
Material and Methods: Multiple electronic databases were searched using appropriate MeSH terms and keywords for original English language research papers published between 1990 and March 2014. Meta-analyses results were based on the mean differences between the groups as well as odds ratios where appropriate. Statistical heterogeneity amongst the included studies was tested by I^2 index.
Results: Nine studies that met the inclusion criteria were selected for analysis which consisted of 556 parturient patients. The duration of the second stage of labor was significantly shorter in the BUPI-FEN group by a mean of –6.87 (–10.98, –2.77; P<0.002). On the other hand, the ROPI-FEN group had a significantly lower incidence of motor blockade by a mean of 0.31 (0.18, 0.51; P<0.00001). A positive relationship between the amide local anesthetic concentration and the number of women having motor blockade was observed, but a negative relationship between fentanyl concentration and the number of women experiencing a motor block. Moreover, a positive correlation was found between the concentration of ropivacaine and the incidence of instrumental delivery and between the concentration of bupivacaine and the incidence of cesarean delivery.
Conclusions: In combination with fentanyl, bupivacaine and ropivacaine exhibit comparable efficacy and safety. However, BUP-FEN analgesia led to a shortened second-stage labor and ROPI-FEN resulted in a significantly lower incidence of motor block.

Keywords: Amides - therapeutic use, Adult, Analgesia, Epidural, Anesthetics, Local - therapeutic use, Bupivacaine - therapeutic use, Drug Therapy, Combination, Fentanyl - therapeutic use, Labor Pain - drug therapy, Nerve Block, Odds Ratio, Pregnancy, Publication Bias, Risk Factors