Erector Spinae Plane Block in Scoliotic Adolescents

The linear multi-frequency 6-13 megahertz transducer will be used. In the prone position,under aseptic conditions, the probe will be placed in a longitudinal position 2-3 cm lateral to the vertebral column. The transverse processes of the vertebrae at (mid) level of surgery, the Erector Spinae muscle and the psoas muscle are identified. A 22 gauge echogenic needle will be inserted in an in plane technique in a cephalad to caudad direction until bone contact with the top of the transverse process is reached. After slight retraction of the needle, A test dose of 5% dextrose in water can expand the fascial plane and confirm needle-tip location prior to injection of local anaesthetic. Then, 0.5 ml/kg of bupivacaine 0.25% with 0.1 mg/kg dexamethasone and adrenaline 1 : 200000 will be injected between erector spinea muscle and transverse process, taking in consideration not exceeding the toxic dose of bupivacaine; 4 mg/kg . the same procedure will be repeated on the contralateral side.

patients will receive an induction dose at 1 mcg/kg. If the analgesia was inadequate in the form of increase in heart rate and or arterial blood pressure by more than 20% of baseline values during surgery, this warrants the administration of intravenous fentanyl (0.5µg/kg).

patients will receive another dose of fentanyl 1 µg/kg 1 minute before start of skin incision.

After end of surgery and emergence from anesthesia, patients will receive continuous intravenous morphine with 0.03 mg/kg/hr.

Morphine IV will be given as rescue analgesia (20 µg/kg) in all study groups if VAS pain score more than 3. The total maximum hourly morphine is 0.75 mg/kg/hr.

After reaching maximum hourly morphine and the patient is still in pain, pethidine will be used as a rescue at 0.5 mg/kg.

patients will receive IV ketorolac from the postoperative second day 15 mg q 6 hours, not to exceed 5 days.

patients will receive postoperative IV acetaminophen IV 10 mg/ kg q 6 hours