Ultrasound-guided trans-incisional quadratus lumborum block versus ultrasound-guided caudal analgesia in pediatric open renal surgery: a randomized trial

Abstract

Background: The caudal route is a common approach for postoperative analgesia; however, it is associated with limited duration of action. The quadratus lumborum block (QLB) may produce prolonged postoperative analgesia. Therefore, this study aimed to compare the postoperative analgesic efficacy of the ultrasound-guided caudal block with that of the ultrasound-guided transincisional QLB (TiQLB) in pediatric patients undergoing open renal surgery.

Methods: Forty patients of both sexes, aged 2-11 years, were randomly assigned to receive either caudal analgesia with 1.25 ml/kg of bupivacaine 0.2% (Caudal group; n = 20) or a QLB with 0.5 ml/kg of bupivacaine 0.2% (TiQLB group; n = 20) in addition to standard general anesthesia. Time to first analgesia was the primary outcome. Total analgesic consumption in the first 24 h postoperatively, pain scores, and the incidence of side effects were the secondary outcomes.

Results: The mean time to first analgesic requirement was significantly longer in the TiQLB group than in the Caudal group (18.8 ± 5.1 vs. 6.7 ± 0.7 h, P < 0.001). Total ketorolac consumption and pain scores were significantly lower in the TiQLB group (P < 0.001). A few cases of mild postoperative nausea and vomiting were noted among patients in both groups; however, the difference was not statistically significant. No incidence of pruritus, shivering, or respiratory depression was noted.

Conclusions: Analgesia after the ultrasound-guided TiQLB with bupivacaine was superior to that after the ultrasound-guided caudal block, with similar side effects.

Keywords: Analgesia; Bupivacaine; Interventional ultrasonography; Nerve block; Pediatrics; Postoperative pain..

Fig. 1.

Ultrasound-guided caudal block, longitudinal axis. A: sacral canal, B: sacroccocygeal ligament.

Fig. 2.

Trans-incisional quadratus lumborum block. (A) Arrow points to the needle between the QLM and PMM, piercing the anterior thoracolumbar fascia. (B) Ultrasound image of the quadratus lumborum block. ES: erector spinae muscle, LA: local anesthetic solution, QLM: quadratus lumborum muscle, PMM: psoas major muscle, TS: transverse lumbar spine.

Fig. 3.

Consolidated Standards of Reporting Trials (CONSORT) flow diagram of patient selection. TiQLB: transincisional quadratus lumborum block.

Fig. 4.

Comparison of hemodynamic parameters between the study groups. (A) Mean arterial pressure (mmHg). (B) Heart rate (beats/min). Lines are the mean data, and the error bars are the SD. TiQLB: transincisional quadratus lumborum block, HR: heart rate, MAP: mean arterial pressure, PO: postoperative.

Fig. 5.

Kaplan-Meier curve for the postoperative analgesia requirement rate among the study groups; the log-rank test was used to compare the rates. QLB: quadratus lumborum block.

Fig. 6.

Comparison of the pain perception (FLACC-10) score between the study groups. Lines represent the mean data, and the error bars are the SD. ^*P < 0.001 compared to the control group. TiQLB: transincisional quadratus lumborum block, FLACC: face, leg, activity, crying, consolability.