Pediatric Postoperative Pain Control With Quadratus Lumborum Block and Dexamethasone in Two Routes With Bupivacaine: A Prospective Randomized Controlled Clinical Trial.

Background: Ultrasound-guided Quadratus Lumborum block (QLB) is a regional analgesia approach that has been reported to provide effective post-operative pain relief for both abdominal and retroperitoneal surgery. Bupivacaine is the most often used and well documented local anesthetic medication in children. Dexamethasone is a systemic glucocorticoid that is often used to minimize postoperative nausea, vomiting, and pain to improve recovery quality after surgery.

Objectives: To evaluate postoperative analgesia of QLB in pediatric patients undergoing renal surgeries by the addition of dexamethasone to bupivacaine compared to intravenous administration.

Study Design: A prospective, randomized, controlled clinical trial.

Setting: Pediatric surgery unit in a university hospital.

Methods: One hundred and five patients (6-12 years old) scheduled for renal surgeries were randomly allocated into 3 groups, with 35 patients in each group. Randomization was based on computer-generated codes. The groups were DEX1 (QLB with IV dexamethasone group), DEX2 (QLB dexamethasone group), and QLB CONTROL (QLB alone). The 1st time for rescue analgesia request, total morphine consumption, Pediatric Objective Pain Scale (POPS), and parents' satisfaction score were measured in 24 hours follow-up to evaluate postoperative pain control.

Results: The time to 1st rescue analgesics request (hours), total morphine consumption (mg), and the parents' satisfaction scores were much better in groups DEX1 and DEX2 as compared to group CONTROL with statistical significance. However, group DEX2 was better than DEX1 in the previous outcomes but without statistical significance. In respect, the pediatric objective pain scale was much lower with a significant difference in groups DEX1and DEX2 in comparison with group CONTROL up to 18 hours postoperatively.

Limitations: Difficult to assess the block as all children were sedated, plus this was a unilateral surgical procedure with limited surgical incision, so the effect of QLB needed to be studied when there is a bilateral surgical procedure.

Conclusions: Dexamethasone may be more effective when added to bupivacaine than when given systemically in analgesic effects without any impact on the other secondary pain-related outcomes. Dexamethasone as an adjuvant to bupivacaine has a marked hand on prolongation of the postoperative duration of analgesia, less request for rescue analgesia, and fewer side effects as compared to bupivacaine if used as a sole agent in QLB.