Ultrasound-Guided Transversus Abdominis Plane Block for Analgesia in Laparoscopic Cholecystectomy: A Systematic Review and Meta-Analysis

OBJECTIVES: To evaluate the analgesic efficacy of ultrasound-guided transversus abdominis plane (TAP) block for patients undergoing laparoscopic cholecystectomy (LC). MATERIALS AND METHODS: A systematic literature search was conducted to identify randomized controlled trials that compared ultrasound-guided TAP block with control for analgesia in adult patients undergoing LC. The original data were pooled for the meta-analysis using Review Manager 5. The main outcomes included postoperative pain intensity, opioid consumption, and adverse events. Out of a total of 77 trials, 7 were included. RESULTS: Compared with control, ultrasound-guided TAP block reduced the following: (1) postoperative pain intensity (visual analog scale: 0-10) both at rest and on movement at 0, 2, 4, 8, and 24 h (at rest: mean difference, MD(0 h) = -2.19, 95% confidence interval, CI: -3.46 to -0.91, p = 0.0008; on movement: MD(0 h) = -2.67, 95% CI: -3.86 to -1.48, p < 0.0001); (2) intraoperative fentanyl consumption (MD = -27.85 µg, 95% CI: -44.91 to -10.79, p = 0.001), and (3) morphine consumption in the recovery room (MD = -1.57 mg, 95% CI: -3.0 to -0.14, p = 0.03) and 0-24 h postoperatively. Fewer patients required analgesics in the recovery room when receiving TAP blocks (risk ratio, RR = 0.35, 95% CI: 0.20 to 0.62, p = 0.0003). TAP blocks also reduced postoperative nausea and vomiting (RR = 0.48, 95% CI: 0.28 to 0.81, p = 0.006). None of the studies reported symptoms of local anesthetic toxicity. CONCLUSIONS: In this study, the ultrasound-guided TAP block was an effective strategy for analgesia in patients undergoing LC.