Efficacy of Transversus Abdominis Plane Block for Acute Postoperative Pain Relief in Kidney Recipients: A Double-Blinded Clinical Trial

After renal transplantation, postoperative pain is usually mild to moderate. Postoperative pain is a concern and administration of systemic analgesic may be difficult because of underlying co-morbidities and variable responses of the graft. The transversus abdominis plane (TAP) block is one of the different approaches for postoperative pain relief following abdominal surgeries. We evaluated analgesic efficacy of TAP block on early postoperative pain by numeric rating scale (NRS) and morphine consumption during the first 24 hours after kidney transplantation. Forty-four patients, scheduled as kidney recipients were randomized into two equal groups and were anesthetized with the same technique. After the induction of anesthesia, 15 mL of 0.25% Bupivacaine plus 5 µ/ml epinephrine or saline was deposited into the transversus abdominis neuro-fascial plane on the side of surgery by ultrasound guide. Each patient was assessed by a blinded investigator using NRS at 1st, 4th, 8th, 12th, and 24th hour postoperatively. Demographic data were not significantly different between the study groups. There was significant difference in median of NRS score measured at all time points in the study groups (P < 0.001). The 24-hour morphine consumption (mean ± SD) was 10.8 ± 9.5 mg in bupivacaine group compared with 41.2 ± 3.8 mg in the saline group (P = 0.001). There was statistically significant reduction in intraoperative fentanyl consumption in the TAP group 120 ± 20 µg compared to the control group 358 ± 24 µg (P = 0.001). In study group 4 patients and in control group 90 patients received morphine titration for pain relief (P = 0.03). There was no complication in the study groups related to nerve block. Only two patients in saline group had nausea (P = 0.07). None of our patients received any other oral or IV rescue medication. Ultrasound TAP block can reduce postrenal transplantation pain and the amount of opioids consumption intraoperatively and during the first 24 hours after surgery in kidney recipients.