Comparison of Norepinehrine Versus Phenylepherine Infusion for Prevention of Post-spinal Hypotension

This prospective randomized double-blinded clinical trial aims to compare the efficacy and hemodynamic effects of prophylactic norepinephrine infusion versus phenylephrine infusion for prevention of spinal anesthesia-induced hypotension in elderly patients undergoing elective orthopedic hip surgery under subarachnoid block. Sixty-two patients aged 60 years or older will be randomly assigned into two equal groups to receive either norepinephrine infusion (8 µg/min) or phenylephrine infusion (100 µg/min) immediately after spinal anesthesia. The primary outcome is the mean heart rate during vasopressor infusion, while secondary outcomes include incidence of hypotension, severe hypotension, bradycardia, reactive hypertension, intraoperative fluid requirements, blood loss, transfusion requirements, and postoperative nausea and vomiting. Hemodynamic parameters will be monitored throughout surg