Intermittent Ephedrine Boluses for Prophylaxis Against Postinduction Hypotension

The aim of this work is to assess the efficacy of intermittent ephedrine boluses in prophylaxis against postinduction hypotension in high-risk patients undergoing major abdominal surgery, compared to standard care.

Inclusion Criteria: * Adult patients aged \>50 years, * weight \>50 kg, * American Society of Anesthesiologists (ASA) Physical Status score of \> I, * undergoing major abdominal surgery Exclusion Criteria: * Severe cardiac morbidities (impaired contractility with ejection fraction \< 40%, heart block, significant uncontrolled arrhythmias, tight stenotic valvular lesions) * Acute cardiovascular pathologies: acute/decompensated heart failure, acute coronary syndrome * Uncontrolled hypertension (systolic blood pressure\>150 mmHg) * Preoperative HR more than 110 bpm despite proper fluid management and patients with renal impairment * Renal impairment * Patients on vasopressor infusion, * Allergy of any of the study drugs