Pediatric Postoperative Analgesia With Quadratus Lumborum Block(QLB) And Dexamethasone As An Adjuvant To Bupivacaine.

After obtaining written informed consent from parents or guardians of all patients, 90 patients (6-12 years old) scheduled for abdominal surgeries operations will be included. Patients will be randomly allocated into three groups, 30 patients in each group. Randomization will be based on computer-generated codes maintained in sequentially numbered opaque envelopes.

Anesthetic Technique:

Anesthesia will be induced with Sevoflurane plus fentanyl (0.5µg/kg) and tracheal intubation will be facilitated with Rocuronium (0.4 mg/kg). Anesthesia will be maintained with Sevoflurane (will be adjusted according to A line autoregressive index (AAI)) and Rocuronium (0.1 mg/kg/dose will be given on the basis of train-of-four neuromuscular monitoring). ECG, noninvasive blood pressure, heart rate, temperature, oxygen saturation, and exhaled CO2 (end tidal CO2) will be continuously monitored during the procedure.

• After induction of anesthesia and before skin incision, a QLB will be performed in all patients in the three groups.

The procedure will be done under ultrasound guidance using curved array transducer 5-2MHz (Sonosite ultrasound system). Echogenic needle, Sono Plex Stim cannula (PAJUNK) 22 gauge and 60 mm length will be used. With the patient in the supine position, the site of the ultrasound and needle entry will be sterilized. The QLB block will be performed by anterior approach. The linear probe will be attached in the area of the triangle of Petit in transverse orientation in lateral abdomen in between the iliac crest and the costal margin, near the posterior axillary line. The muscle planes will be identified until visualizing the quadratus lumborum muscle, at the same plane as the psoas major muscle and the erector spinae. The needle tip is placed at the anterolateral border of the QL at its junction of QL with transversalis fascia outside the anterior layer of the thoracolumbar fascia (TLF) and fascia transversalis, and the local anesthetic will be injected.

Anesthesia will be discontinued when the wound dressing applied, and muscle relaxant will be reversed using (50ug/kg) of neostigmine and atropine (0.02mg/kg) and extubating of the patient will be done. The patient will be transferred to the postoperative care unit (POCU).

Inclusion criteria

• Pediatric patients(6-12 years)
• ASA physical status I,II
• Abdominal surgery

Exclusion criteria

• Parents refusal or legal guardian's refusal
• Allergy to bupivacaine or dexamethasone
• Contraindications to regional techniques
• Failed QLB
• Infection on site of procedure