Erector Spinae Plane Block Versus Fentanyl Infusion in Pediatric Patients Undergoing Aortic Coarcitectomy

fentanyl infusion at a dose of (1 μg/kg/hour) after induction of anesthesia and to be continued all through the whole operation.rescue analgesia by a bolus of (Fentanyl 1mcg/kg) will be given to the patients in either group, if either systolic blood pressure or heart rate increased more than 20% of the baseline readings.

"ultrasound guided erector spinae plane block by injecting 0.4ml/kg (1:1 solution of bupivacaine 0.25% and lidocaine 1%). This will be performed at the same side of the planned thoracotomy under strict aseptic precautions.A high frequency 12 MHz linear ultrasound transducer will be placed in a longitudinal orientation 3 cm lateral to the T3 spinous process corresponding to the T2 transverse process.~Three muscles; trapezius, rhomboids major, and erector spinae will be identified superior to the hyperechoic transverse process.~Using in-plane approach a 25 G needle will be inserted in caudal-cephalic direction, until the tip is deep to erector spinae muscle.~Correct needle tip location will be confirmed by injecting 3 mL of normal saline and visualizing the linear LA spread in the fascial plane between the erector spinae muscle and the transverse process.."