Norepinephrine for Prevention of Intraoperative Hypotension in Infants Undergoing Kasai Portoenterostomy

"anesthesia resident (who will not be involved in patient management to ensure the blinding) will be responsible for preparing norepinephrine infusion or placebo as instructed in the envelope as follow: 1 mg norepinephrine will be diluted in dextrose 5% in a 50 mL syringe using a nomogram based on the infant body weight so that 1mL= 0.05 µg/kg/min norepinephrine infusion.~the attending anesthetist will be instructed to set the 2 syringe pumps on 2 mL/h continuous infusion following skin incision."

Placebo