Local anesthetic infiltration for postoperative pain relief after laparoscopy: a qualitative and quantitative systematic review of intraperitoneal, port-site infiltration and mesosalpinx block.

In a systematic review, we evaluated randomized controlled trials (RCTs) of peripheral local anesthetics (LA) compared with placebo or no treatment in the control of postoperative pain after laparoscopic surgery. A total of 41 trials with data from 2794 patients were considered appropriate for analysis. Of these 41 RCTs, 13 evaluated intraperitoneal LA after cholecystectomy, four RCTs assessed intraperitoneal LA after other procedures, eight RCTs evaluated port-site infiltration after various procedures, 12 RCTs evaluated mesosalpinx or fallopian tube block after sterilization, and four RCTs considered combined LA regimens. Outcome measures were pain scores, analgesic consumption, and time to first analgesic request. Efficacy was estimated by significant difference (P < 0.05), as reported in the original reports, and by calculation of the weighted mean difference of visual analog scale pain scores between treatment groups. Improved pain relief was observed in seven of the 13 RCTs of intraperitoneal LA after cholecystectomy and in four RCTs of other procedures. A statistically significant weighted mean difference of -13 mm visual analog scale (95% confidence intervals [CI]: -20 to -6) in favor of the treatment groups was observed after cholecystectomy. Three of eight trials of port-site infiltration showed significant differences but questionable clinical importance and validity in two; weighted mean difference was not statistically significant between treatment groups (95% CI -9 to 1). All RCTs of mesosalpinx or fallopian tube block after sterilization showed improved pain relief with a statistically significant weighted mean difference of -19 mm (95% CI -25 to -14) in favor of treatment groups. Data of combined regimens were positive, however, sparse. We conclude that there was evidence for a statistically significant but clinically questionable, important effect of intraperitoneal LA for postoperative pain control. There was evidence for a significant but short-lasting effect of mesosalpinx/fallopian tube block after sterilization, but there was a lack of evidence for any important effect of port-site infiltration. Data from combined regimens were too sparse for conclusions.