Erector Spinae Plane Block Versus Quadratus Lumborum Block for Open Renal Surgeries in Children

Using a 22-gauge 80 mm echogenic needle under ultrasound guidance, 0.5 mL/kg of bupivacaine 0.125% will be injected in the fascial plane deep to erector spinae muscle after confirming correct needle location by a negative aspiration test then by injecting 0.5-1 ml saline and observing the fluid lifting the erector spinae muscle off the transverse process (hydrodissection). The ultrasound probe will be placed 2-3 cm lateral to the spinous process on a parasagittal plane, to visualize the erector spinae muscle and transverse process, directing the needle craniocaudally using the in-plane technique. The spread of the injectate will be observed to distribute within this plane.

Using a 22-gauge 80 mm echogenic needle under ultrasound guidance, 0.5 mL/kg of bupivacaine 0.125% will be injected in the fascial plane between the quadratus lumborum and psoas major muscle after confirming correct needle location by a negative aspiration test then by injecting 0.5-1 ml saline (hydrodissection). The ultrasound probe will be placed 2-3 cm lateral to the L2 spinous process on an axial plane, to visualize the transverse process with psoas major muscle anterior, quadratus lumborum muscle lateral and erector spinae muscle posterior to it. The needle is inserted from the medial side of the probe and advanced laterally using the in-plane technique. The spread of the injectate will be observed to distribute within the target plane.

Sonosite S-Nerve (USA) with a linear multi-frequency 6-13 MHz (hockey stick) transducer

A 22-gauge 80 mm needle the sonoplex needle manufactured by PAJUNK (USA)

Given intravenously (1 µg/kg) as part of induction of general anesthesia (GA) added to propofol 2 mg/kg and atracurium 0.5 mg/kg Intraoperatively, intravenous fentanyl 0.5 µg/kg (with a maximum dose of 2 µg/kg) will be administered in response to any increase in hemodynamics by more than 20% of baseline values in response to skin incision or there after throughout surgery (after exclusion of other causes of hemodynamic changes)

Will be given intravenously as a rescue analgesic (0.5 mg/kg with maximal dose 1.5 mg/kg) in both study groups if Children's Hospital Eastern Ontario Pain Scale (CHEOPS) more than 6. Quality of postoperative analgesia will be assessed using CHEOPS pain score at time transfer to PACU, 15, 30 minutes then 1, 2, 4, 6 hours postoperatively.