Pericapsular Nerve Group Block Combined Versus Trans Muscular Quadratus Lumborum Block in Pediatric Patients Undergoing Correction of Dysplasia of the Hip: a Prospective Randomized Double Blinded Study

Patients of both study groups will be monitored using standard monitors Electrocardiogram, pulse oximeter and automated non-invasive blood pressure (NIBP). After preoxygenation, general anesthesia will be induced by a face mask and 8% sevoflurane and 100 % oxygen, then intravenous cannula will be inserted. Fentanyl 1 µg/kg will be given and after neuromuscular block is achieved with atracurium 0.5 mg/kg and the trachea is intubated. Anesthesia will be maintained with isoflurane 1.2% and 60% oxygen and the maintenance dose of atracurium 0.1 mg/kg each 20 minutes. Ringer lactate will be infused at 10 ml/kg per hour in first hour then by the rule 4-2-1 ml per kg per hour.

The blocks will be performed after induction of anesthesia and under ultrasound guidance using SonoSite M Turbo (USA); the scanning probe will be the linear multi-frequency 6-13 MHz transducer (L25 x 6-13 MHz linear array).

Patients will be randomly allocated into two equal groups: PENG block (P group) and TQL block (Q group).

In PENG block group:

With the patient in the supine position, the skin is disinfected, sterile drapes are used, the transducer is wrapped with a sterile dressing, and sterile ultrasound gel is used for scanning, the transducer is placed in the transverse plane over the anterior inferior iliac spine (AIIS) and moved inferiorly to visualize the pubic ramus. The femoral artery and iliopubic eminence are visualized, and then, using an in-plane technique, a 22-gauge 50 mm needle is advanced from lateral to medial through the skin wheal at a 30-degree to 45-degree angle toward the ultrasound beam, Aspiration will be performed before injection, then 0.5 ml/kg of 0.25% bupivacaine is deposited between the psoas tendon anteriorly and pubic ramus posteriorly lifting it .16 To perform the LFCN block: again, the patient in supine position, the skin is disinfected, sterile drapes are used, the transducer is wrapped with a sterile dressing, and sterile ultrasound gel is used for scanning, the transducer is placed immediately inferior to the anterior superior iliac spine (ASIS), parallel to the inguinal ligament. The tensor fasciae lata muscle (TFLM) and sartorius muscle (SaM) are then identified. The nerve should appear as a small hypoechoic oval structure with a hyperechoic rim between the TFLM and SaM in a short-axis view or superficial to the SaM. A 22-gauge 50 mm needle is inserted in-plane in a lateral-to-medial orientation through the subcutaneous tissue. A fascial "pop" or "click" may be felt as the needle tip enters the plane between the TFLM and SaM. To identify the needle tip position, a volume of 0.5-1 mL of isotonic saline may be injected. The correct position is achieved by visualizing the spread of 0.1 ml/kg of 0.25% bupivacaine in the described plane between the TFLM and SaM or around the LFCN superficial to the SaM.9 The dose of bupivacaine in both blocks should not exceed 2.5mg per kg as they will be administrated in the same patient.