Ultrasound-guided Anterior Quadratus Lumborum Block for Postoperative Pain after Laparoscopic Pyeloplasty: A Randomized Controlled Trial

BACKGROUND: Quadratus lumborum block (QLB) has provided adequate analgesia and lowered postoperative opioid requirement in comparison to controls for some urological surgeries. AIMS: The aim of this study was to assess the efficacy of postprocedure ultrasound-guided QLB in comparison to port-site infiltrations with local anesthetics (as control) in lowering postoperative pain after laparoscopic pyeloplasty. SETTINGS AND DESIGN: This was a prospective, single-blinded, randomized controlled trial. MATERIALS AND METHODS: Fifty-three adults undergoing laparoscopic pyeloplasty were randomly allocated to either anterior QLB group (n = 27) or port-site infiltration Group P (n = 26) with 20 mL of 0.5% ropivacaine. The primary outcomes were static and dynamic pain on the Visual Analog Scale (VAS) of 0–100 at the 30(th) min, 2(nd), 6(th), 12(th), and 24(th) hour after surgery. The secondary outcomes were number of patients requiring rescue analgesics and having postoperative nausea or vomiting (PONV) in 24 hours after surgery. STATISTICAL ANALYSIS: Intergroup comparison of VAS was done with Student's t-test. Categorical data were analyzed using the Chi-square test. RESULTS: The static VAS scores were found to be significantly lower in QLB group at the 2(nd), 6(th), and 12(th) hour, and the dynamic VAS was lower at all time points after the 30(th) min in the QLB group. The number of patients requiring rescue analgesics were significantly lower in the QLB group (13 as compared to 21 in Group P; P = 0.015). The incidence of PONV was comparable. No other side effects were seen. CONCLUSION: Ultrasound-guided anterior QLB is more effective in comparison to traditional technique of port-site local anesthetic infiltration for providing analgesia after laparoscopic pyeloplasty.