Transversus abdominis plane block versus quadratus lumborum block type 2 for analgesia in renal transplantation

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 −1 versus 6.7 [3.5 to 10.7] μg kg −1 , 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.