Addition of preoperative transversus abdominis plane block to multimodal analgesia in open gynecological surgery: a randomized controlled trial

Background Transversus abdominis plane (TAP) block can provide effective analgesia for abdominal surgery. However, it was questionable whether TAP had additional effect in the context of multimodal analgesia (MMA). Therefore, this study aimed to assess the additional analgesic effect of preoperative TAP block when added to MMA protocol in open gynecological surgery.Methods In this prospective, randomized-controlled trial, 64 patients scheduled for open gynecological surgery were randomized to receive preoperative TAP block (Study group, n = 32) or placebo (Control group, n = 32) in addition to MMA protocol comprising dexamethasone, acetaminophen, flurbiprofen and celecoxib, and rescued morphine analgesia. The primary outcome was rescued morphine within 24 h after surgery. Secondary outcomes included pain scores, adverse effects, quality of recovery measured by 40-item quality of recovery questionnaire score (QoR-40) at 24 h, and quality of life measured with short-form health survey (SF - 36) on postoperative day (POD) 30.Results The Study group had less rescued morphine than the control group within 24 h [5 (2-9) vs. 8.5 (5-12.8) mg, P = 0.013]. The Study group had lower pain scores at 1 h [3 (2-4) vs. 4 (3-5), P = 0.007], 2 h [3 (2-4) vs. 3.5 (3-5), P = 0.010] and 6 h [3 (2-3) vs. 3 (2.3-4), P = 0.028], lower incidence of nausea at 48 h (25.8% vs. 50%, P = 0.039), and higher satisfaction score [10 (10-10) vs. 10 (8-10), P = 0.041]. The SF-36 bodily pain score on POD 30 was higher in the Study group (59 +/- 13 vs. 49 +/- 16, P = 0.023).Conclusions Preoperative TAP block had additional analgesic effect for open gynecological surgery when used as part of multimodal analgesia. Rescued morphine within 24 h was significantly reduced and the SF-36 bodily pain dimension at 30 days after surgery was significantly improved.