Continuous Versus Bolus Norepinephrine Administration to Treat Postinduction Hypotension

Inclusion Criteria: We will include consenting patients ≥45 years scheduled for elective major non-cardiac surgery under general anesthesia with planned continuous intra-arterial blood pressure monitoring with a radial arterial catheter and with at least two of the following risk criteria for developing acute kidney injury: * Age ≥65 years * ASA physical status III or IV * Chronic arterial hypertension * Diabetes mellitus requiring medication * Intra-abdominal surgery * Preoperative renal insufficiency (serum creatinine ≥1.2 mg/dL) Exclusion Criteria: * Pregnancy * Cardiac arrhythmia * History of intracranial hemorrhage or intracranial aneurysm * Clinical indication for continuous norepinephrine infusion during induction of general anesthesia (e.g., severe aortic valve stenosis, coronary artery disease, or heart failure) * Patients who are unable to understand, read, and provide informed consent in German