Ketamine's Immediate Analgesia and Opioid-Sparing Benefits in Laparoscopic Cholecystectomy: A Meta-Analysis of Time Points, Anesthesia Protocols, and Bolus/Infusion Strategies.

Abstract

Objectives: Laparoscopic cholecystectomy (LC), though minimally invasive, sometimes leads to significant postoperative pain. Ketamine has shown potential in alleviating it, but small sample sizes and administration protocols variability limit prior findings generalizability. This study evaluates ketamine's effectiveness in reducing postoperative pain across multiple time points.

Methods: A thorough search of multiple databases was conducted, covering publications up to January 2025. Data from eligible randomized controlled trials (RCTs) were extracted and pooled to calculate mean differences (MDs) for postoperative pain scores at 30 minutes, 1 hour, 2 hours, 4 hours, and 12 hours, alongside opioid consumption (morphine and tramadol) and adverse events.

Results: The analysis included 22 RCTs with 1,163 participants. Ketamine significantly reduced postoperative pain compared to placebo (MD=-0.37, 95% CI [-0.56 to -0.17], P=0.0002). Subgroup analyses at 30 minutes showed significant pain reduction in bolus + infusion (MD=-0.70, 95% CI [-1.33 to -0.07], P=0.03), bolus alone (MD=-1.28, 95% CI [-2.29 to -0.27], P=0.01), and propofol-based maintenance (MD=-0.89, 95% CI [-1.44 to -0.34], P=0.002). Additionally, ketamine significantly reduced morphine (MD=-0.46, 95% CI [-0.91 to -0.02], P=0.04) and tramadol consumption (MD=-1.03, 95% CI [-1.86 to -0.21], P=0.01).

Discussion: Ketamine reduced opioid use and postoperative pain at 30 minutes, with efficacy varying by administration method. Future RCTs should standardize dosage, anesthesia protocols, and pain management strategies to enhance evidence consistency.