The efficacy of transversus abdominis plane block with or without dexmedetomidine for postoperative analgesia in renal transplantation. A randomized controlled trial.

BACKGROUND Current options for effective postoperative analgesia after renal transplantation are limited, due to altered renal clearance and the risk of renal damage. This study compared the analgesic effect of the transversus abdominis plane block, with or without dexmedetomidine, in renal transplant recipients. MATERIALS AND METHODS This prospective randomized double-blinded clinical trial was performed from November 2014 to March 2017. Patients were randomly divided into group C (morphine intravenous patient-controlled analgesia), group R (morphine intravenous patient-controlled analgesia and transversus abdominis plane block), and group RD (morphine intravenous patient-controlled analgesia and transversus abdominis plane block with 1 μg/kg dexmedetomidine). Morphine consumption, time to first request for analgesia, pain, sedation, nausea, vomiting, respiratory depression, and bradycardia were measured at 2, 4, 6, 12 and 24 hours after surgery. RESULTS The visual analogue pain score in group C was the highest among the three groups at the 2nd and 4th hour. Morphine consumption was the highest in group C at all assessed time intervals (p < 0.01). By the 12th hour and 24th hour, morphine consumption (calculated by time interval) was the lowest in group RD (p < 0.05), while no statistical difference was found between groups C and R. The average time to first request of analgesia was the longest and shortest in group RD and group C, respectively (p < 0.01). The overall incidence of nausea and vomiting was the highest in group C (p < 0.05). CONCLUSIONS The transversus abdominis plane block reduced morphine consumption in the first 24 hours following renal transplantation, and the addition of dexmedetomidine provided a more effective analgesic effect.