Ultrasound-Guided Transmuscular Quadratus Lumbar Block Reduces Opioid Consumption after Laparoscopic Partial Nephrectomy.

Objectives Transmuscular quadratus lumborum block (TQLB) may provide postoperative analgesia in patients undergoing intraperitoneal surgeries. The purpose of this study was to examine the potential efficacy of TQLB among patients undergoing retroperitoneal procedures, such as the laparoscopic partial nephrectomy (LPN). Methods This prospective, randomized, controlled study was conducted from August 2017 to November 2018 at Peking Union Medical College Hospital (Beijing, China). Patients who were scheduled for a LPN, aged 18-70 years old with an ASA physical status score of I - II were randomly assigned to receive either TQLB with 0.6 ml/kg of 0.5% ropivacaine plus general anesthesia (TQLB group) or general anesthesia alone (control group). Patient-controlled intravenous analgesia with morphine was initiated immediately upon surgery completion. The primary outcome was the cumulative consumption of morphine within 8 h after surgery. The secondary outcome included postoperative consumptions of morphine at other time points, pain score at rest and during activity, postoperative nausea and vomitting (PONV), and recovery related parameters. Results Totally 30 patients per group were recruited in the study. The 8 h consumption of morphine was lower in the TQLB group than in the control group (median, 0.023 mg/kg vs . 0.068 mg/kg, U=207.5, P <0.001). No significant differences were observed in postoperative pain scores between the two groups. Patients in the TQLB group had fewer episodes of PONV (20% vs. 47%, χ ² =4.8, P =0.028) in the first 24 h after surgery and higher scores for quality of recovery (mean, 138.6 vs. 131.9, t =-2.164, P =0.035) 120 h after surgery than the controls. Conclusions TQLB resulted in an opioid-sparing effect during the early postoperative period following LPN, as well as a lower incidence of PONV and improved quality of recovery.