The effectiveness of Bupivacaine as a pre-emptivepudendal block among patients undergoing vaginal surgeries: meta-analysis of randomized controlled trials

Abstract

Background: Pre-emptive analgesia using pudendal nerve block (PNB) with bupivacaine is commonly used in clinical practice during pelvic floor and vaginal surgeries. However, its effectiveness is unclear. To update the evidence base we summarised short- and intermediate-term outcomes of pre-emptive analgesia using pudendal nerve block with bupivacaine as an approach in the management of pelvic floor and vaginal surgeries. Methods: We searched the CENTRAL, PubMed, ClinicalTrials.gov, google scholar and Open Grey from inception until April 2019. The citation lists of relevant papers were also searched. Randomized controlled trials (RCTs) of women who underwent perineal, pelvic floor or vaginal surgeries and received pre-emptive analgesia using a pudendal nerve block were included. Two authors independently screened and selected eligible trials as well as performed data extraction and quality assessment. Disagreements were resolved via consensus and an adjudicator was involved when consensus was not achieved. Data was narratively synthesized, when possible, data was pooled in RevMan 5 using random effects model. Results: Four RCTs with a total of 349 participants were eligible for inclusion. We found evidence of small effect for improvement in post-operative pain scores; requirements for opioids, SMD: -0.89 (95% CI: -1.19, -0.59) and non-steroidal anti-inflammatories SMD -1.04 (95% CI: -1.64, -0.43) in favour of the PNB versus control group. The risk ratio for adverse effects 0.42 (95% CI: 0.18, 0.99) favoured PNB. There was no significant difference between groups for length of hospital stay, MD: -0.82 (95% CI: -5.34, 3.69) and return to normal activity. Conclusion:We found inconclusive evidence that pre-emptive pudendal block using bupivacaine may improve postoperative pain and recovery in perineal, pelvic floor or vaginal surgeries. However, due to the scant and poor quality of evidence included in this systematic review, well-designed and adequately powered RCTs that adhere to reporting guidelines and evaluate key outcomes are needed to inform clinical guidelines on the use of pre-emptive pudendal block. Key words:pre-emptive analgesia, bupivacaine, pudendal nerve block, vaginal surgery, pelvic organ prolapse, systematic review, meta-analysis