Transversus abdominis plane block versus quadratus lumborum block type 2 for analgesia in renal transplantation: A randomised trial.

BACKGROUND: Several studies have shown an analgesic efficacy of a transversus abdominis plane block (TAPB) in reducing opioid requirements during and after cadaveric renal transplantation surgery, but the effect of a quadratus lumborum block (QLB) in this type of surgery is unclear. OBJECTIVES: The main objective of this prospective, randomised, double-centre clinical study was to compare the analgesic efficacy of a one-sided lateral approach TAPB with a unilateral QLB type 2 in cadaveric renal transplantation surgery. DESIGN: Randomised, single-blinded trial. SETTING: Two University-affiliated tertiary care hospitals between April 2016 and May 2017. PATIENTS: A total of 101 patients aged more than 18 years, scheduled for cadaveric renal transplantation. INTERVENTIONS: On receiving ethical board approval and individual informed consent, consecutive patients were allocated randomly to receive either an ultrasound-guided single-shot lateral TAPB or an ultrasound-guided single-shot QLB type 2 on the surgical side using 20 ml of bupivacaine 0.25% with adrenaline after a standardised induction of general anaesthesia. All patients on surgical completion and recovery from general anaesthesia were admitted to the postanaesthesia care unit for 24 h. They received standardised intravenous patient-controlled analgesia with fentanyl, and their pain scores were noted at regular intervals. MAIN OUTCOME MEASURES: The primary endpoint was total cumulative fentanyl dose used per kg body mass in the first 24 h after surgery. Secondary outcomes were the need to start a continuous infusion of fentanyl in addition to patient-controlled analgesia boluses during the stay in post-anaesthesia care unit, postoperative pain severity measured using a numerical rating scale, patient satisfaction with analgesic treatment, evidence of postoperative nausea and vomiting, pruritus and sedation level. RESULTS: The 49 patients allocated to the QLB type 2 group used significantly less fentanyl per kg in the first 24 h after surgery than the 52 patients who received a TAPB (median [IQR] 4.2 [2.3 to 8.0] µg kg versus 6.7 [3.5 to 10.7] µg kg, P = 0.042). No statistically significant differences were noted in the secondary endpoints within the study, including the frequency of adverse effects of opioids. CONCLUSION: The reduction of fentanyl consumption in the first 24 h after renal transplantation with no difference in pain intensity and patient satisfaction shows a beneficial effect of one-sided QLB type 2 over a one-sided TAPB in regards to postoperative analgesia. However, the reduction in opioid consumption did not affect the frequency of opioid-related adverse effects. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT02783586.