BACKGROUND: The increasing use of the transversus abdominis plane (TAP) block, as a form of pain relief after laparoscopic surgery, warrants evaluation of its effectiveness, when compared with other analgesic techniques. METHODS: We searched online databases of MEDLINE, EMBASE, Google scholar and The Cochrane Database of Systematic Review. Mean differences (MD) were formulated for continuous data; odds ratios (OR) were calculated for dichotomous data. Results were produced with a random effects model with 95% confidence intervals (CI). RESULTS: 14 trials with a total of 905 patients were included for the analysis, TAP block resulted in significantly less postoperative analgesic consumption at 24 h (MD = -25.46, 95% CI [-32.22, -18.69], P < 0.00001), and less number of patients requiring analgesic postoperatively (OR = 0.16, 95% CI 0.03-0.87, P = 0.03). Meanwhile, pain sores were significantly different at 2 h (MD = -1.55, 95% CI [-2.50, -0.59], P < 0.00001), a borderline difference between the groups seen at 6 hours ( MD = -1.13, 95% CI [-1.69, -0.56], P = 0.05), and there was not affect pain at 24 h (MD = -0.33, 95% CI [-0.08, 0.15], P = 0.14) with TAP block groups compared with the groups without TAP block. There was a significant difference in postoperative nausea and vomiting (random effects model: OR = 2.04, 95% CI [1.19-3.48], P = 0.34). CONCLUSION: TAP block would result in less analgesic consumption, less requirement of analgesic, and less pain at 2 h and slightly at 6 h but at 24 h after laparoscopic surgery in comparison with usual care alone or placebo block. In addition TAP block can increase the incidence of postoperative nausea and vomiting.
KEYWORDS: TAP block; laparoscopic surgery; meta-analysis; transversus abdominis plane block
Can J Anaesth. 2012 Aug;59(8):766-78. doi: 10.1007/s12630-012-9729-1. Epub 2012 May 24.
PURPOSE: To assess the efficacy of transversus abdominis plane (TAP) block in improving analgesia following Cesarean delivery (CD). SOURCE: We searched MEDLINE, CENTRAL, EMBASE, and CINAHL for randomized controlled trials that assessed the efficacy of TAP block following CD and reported on postoperative pain scores and/or opioid consumption. Studies were combined according to the use or non-use of intrathecal morphine (ITM). Another analysis was performed for studies comparing TAP block with ITM. PRINCIPAL FINDINGS: Nine studies were included. Transversus abdominis plane block significantly reduced opioid consumption (mg morphine equivalents) after Cesarean delivery at six hours (mean difference [MD] -10.18; 95% confidence interval [CI] -13.03 to -7.34), at 12 hr (MD -13.83; 95% CI -22.77 to -4.89), and at 24 hr (MD -20.23; 95% CI -33.69 to -6.77). The TAP block also reduced pain scores for up to 12 hr and nausea in patients who did not receive ITM. When added to ITM, TAP block produced a small reduction in pain scores on movement in the first six hours (MD -0.82, 95% CI -1.52 to -0.11). When compared with ITM, pain scores on movement and opioid consumption at 24 hr were lower (MD 0.98; 95% CI 0.06 to 1.91 and MD 8.42 mg; 95% CI 1.74 to 15.10, respectively), and time to first rescue analgesic was longer with ITM (8 hr vs 4 hr), although opioid-related side effects were more common. CONCLUSION: Transversus abdominis plane block significantly improved postoperative analgesia in women undergoing CD who did not receive ITM but showed no improvement in those who received ITM. Intrathecal morphine was associated with improved analgesia compared with TAP block alone at the expense of an increased incidence of side effects.