Background and aims The aim of this prospective hospital-based comparative study was to compare the postoperative analgesic efficacy of intravenous fentanyl patient-controlled analgesia (IVPCA) with and without quadratus lumborum block (OLB).

Methods 28 patients undergoing abdominal surgery were randomly divided into two groups for postoperative analgesia, ie, an IVPCA group receiving a 10 μg/mL fentanyl bolus of 15 μg with a 10-minute lockout and a maximum hourly dose of 90 μg, and an IVPCA + OLB group that additionally received QL block (0,3 mL per kg of 0.375% bupivacaine) on both sides via a posterior approach with ultrasound guidance before skin incision. Postoperatively, bolus injections of bupivacaine 0.375% were given every 8 hours through a QLB catheter.

Results Age, weight, and sex were comparable between the groups (P>0.05). the visual analog scale score was significantly lower at 12, 18, 24, 48, and 72 hours (P<0.01) in IVPCA + QLB group. the Ramsay sedation score was lower only after 72 hours in the IVPCA + QLB group when compared with the IVPCA group (1.49±0.63 versus 2.21±0.52, respectively, P<0.01). Heart rate, systolic blood pressure, and fentanyl consumption were lower in the IVPCA + QLB group at 24, 48, and 72 hours (P<0.05). Intensive care unit stays were significantly shorter with QLB (2.81±0.34 days versus 4.28±0.78 days, P<0.01).

Conclusions Combining QLB with IVPCA improved postoperative pain management and reduced fentanyl consumption, with a shorter stay in intensive care. OLB block can be included as part of a balanced multimodal postoperative pain regimen in children.