Ultrasound-guided transversus abdominis plane block for radical cystectomy with and without dexamethasone: a prospective, double-blinded controlled trial

Introduction Poor control of pain after major abdominal surgeries is associated with a variety of unwanted consequences. The transversus abdominis plane ( TAP) block provides analgesia to the parietal peritoneum and to the skin and muscles of the anterior abdominal wall. Different adjuvants including dexamethasone have been used to intensify the quality and increase the duration of local anesthetics. The aim of the study was to assess the efficacy of TAP block and to measure the effect of adding dexamethasone to bupivacaine on the quality of TAP block. Patients and methods Ninety ASA I– III patients, scheduled for radical cystectomy under general anesthesia, were enrolled in the study and were divided into three groups: group I was given TAP block with 20 ml 0.25% bupivacaine + 2 ml dexamethasone (8 mg)/side (n = 30); group II was given TAP block with 20 ml of 0.25% bupivacaine + 2 ml saline 0.9%/side (n = 30); and group III was given general anesthesia without TAP block (n = 30). The primary outcome was postoperative pain evaluated using the visual analogue scale ( VAS) score for pain at 2, 4, 6, 12, and 24 h postoperatively, whereas the secondary outcome was the time to first analgesia ( TFA), morphine consumption, and incidence of nausea or sedation. Results Adding dexamethasone to bupivacaine compared with bupivacaine alone resulted in a reduction in the postoperative VAS for pain score, a longer TFA (220.5 ± 25.02 vs. 140.54 ± 15.12 min, P 0.001), and lesser 24-h morphine consumption (5.11 ± 3.01 vs. 17.20 ± 7.75 mg, P 0.001). The bupivacaine TAP group compared with the control group showed a significant reduction of the VAS pain score, a longer TFA (140.54 ± 15.12 vs. 35.055 ± 4.15 min, P = 0.01), and lesser 24-h morphine requirement (17.20 ± 7.75 vs. 27.58 ± 8.41 mg, P 0.001). Both TAP block groups compared with the control group showed a significant reduction of nausea and a lower incidence of sedation. Conclusion TAP block with bupivacaine provided better analgesia with fewer side effects compared with conventional systemic analgesia. Adding dexamethasone to bupivacaine in TAP block added better analgesic effect.