Effect of intraperitoneal local anesthetic on pain characteristics after laparoscopic cholecystectomy

AIM: To systematically evaluate the effect of intraperitoneal local anesthetic on pain characteristics after laparoscopic cholecystectomy (LC). METHODS: We searched MEDLINE, EMBASE, and the Cochrane Library. Randomized controlled trials in English that compared the effect of intraperitoneal administration of local anesthetics on pain with that of placebo or nothing after elective LC under general anesthesia were included. The primary outcome variables analyzed were the combined scores of abdominal, visceral, parietal, and shoulder pain after LC at multiple time points. We also extracted pain scores at resting and dynamic states. RESULTS: We included 39 studies of 3045 patients in total. The administration of intraperitoneal local anesthetic reduced pain intensity in a resting state after laparoscopic cholecystectomy: abdominal [standardized mean difference (SMD) = -0.741; 95% CI: -1.001 to -0.48, P < 0.001]; visceral (SMD = -0.249; 95% CI: -0.493 to -0.006, P = 0.774); and shoulder (SMD = -0.273; 95% CI: -0.464 to -0.082, P = 0.097). Application of intraperitoneal local anesthetic significantly reduced the incidence of shoulder pain (RR = 0.437; 95% CI: 0.299 to 0.639, P < 0.001). There was no favorable effect on resting parietal or dynamic abdominal pain. CONCLUSION: Intraperitoneal local anesthetic as an analgesic adjuvant in patients undergoing laparoscopic cholecystectomy exhibited beneficial effects on postoperative abdominal, visceral, and shoulder pain in a resting state.