Effect of intravenous ketamine for postoperative analgesia in patients undergoing laparoscopic cholecystectomy: A meta-analysis

BACKGROUND: We conducted a meta-analysis to assess the efficacy and safety of ketamine for reducing pain and narcotic use for patients undergoing laparoscopic cholecystectomy (LC). METHODS: PubMed, Embase, Web of science, Medline, and Cochrane library databases were systematically searched. Randomized controlled trials (RCTs) were regarded as eligible in our study. After testing the heterogeneity across RCTs, data were aggregated for fixed/random effect model according to the I(2) statistic. The meta-analysis was conducted using Stata 11.0 software. RESULTS: Five studies were included, with a total sample size of 212 patients. Current meta-analysis revealed that there were significant differences regarding postoperative pain score at 12 hours [standard mean difference (SMD) = −0.322, 95% confidence interval (95% CI): −0.594 to −0.050, P = .020], 24 hours (SMD = −0.332, 95% CI: −0.605 to −0.059, P = .017), and 48 hours (SMD = −0.340, 95% CI: −0.612 to −0.068, P = .014). Ketamine intervention was found to significantly decrease narcotic use at 12 hours (SMD = −0.296, 95% CI: −0.567 to −0.025, P = .033), 24 hours (SMD = −0.310, 95% CI: −0.581 to −0.039, P = .025), and 48 hours (SMD = −0.338, 95% CI: −0.609 to −0.066, P = .015). CONCLUSION: Ketamine appeared to significantly reduce postoperative pain and narcotic use following LC. On the basis of the current evidence available, higher quality RCTs are still required for further research.