Addition of dexmedetomidine or fentanyl to ropivacaine for transversus abdominis plane block: evaluation of effect on postoperative pain and quality of recovery in gynecological surgery

BACKGROUND: Transversus abdominis plane (TAP) block is reportedly a preferable technique for reducing postoperative pain in abdominal surgeries. The aim of this study was to compare the analgesic efficacy and recovery quality after gynecological surgery by adding dexmedetomidine or fentanyl into an ultrasound-guided TAP block. METHODS: We randomly assigned 100 elective gynecological patients into four groups (TAP, TAP-DEX, TAP-FEN, and control, n=25 in each). TAP blocks were performed postoperatively. The control group received patient-controlled intravenous analgesia (PCIA), the TAP group received TAP blocks with 0.375% ropivacaine, the TAP-DEX group received 0.375% ropivacaine with dexmedetomidine 1 µg/kg, and the TAP-FEN group received 0.375% ropivacaine with fentanyl 1 µg/kg. The primary outcomes were the first request time for PCIA bolus and quality of postoperative recovery assessed using the QoR-40 questionnaire 2 days after surgery. The secondary outcomes were the visual analog scale (VAS) scores at rest across the different time intervals, the total number of PCIA boluses required in 24 and 48 hours postoperatively, and associated complications. RESULTS: The first request time for PCIA was significantly longer in the TAP-DEX than in the TAP, TAP-FEN, and control groups (9.86±0.77, 7.86±0.56, 8.79±0.55, and 1.56±0.65 hours, respectively; P<0.01). The QoR-40 scores were highest in the TAP-DEX group (P<0.05). The mean PCIA bolus consumption in the first 24–48 hours was lowest in TAP-DEX group. VAS showed significant differences between TAP-DEX and TAP-FEN groups only at 6 hours (P<0.01). CONCLUSION: The use of dexmedetomidine as an adjuvant to TAP blocks could facilitate postoperative analgesia and improve the quality of recovery without increasing related complications.