Can a simple infusion keep blood pressure stable during surgery?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. ≥45 years old 2. Elective or accelerated\* non-cardiac surgery expected to last ≥1 hour and requiring general, neuraxial, or combined general with neuraxial anesthesia 3. Expected to stay overnight in the hospital after surgery 4. Written informed consent to participate in the HYP-NOR Trial provided 5. American Society of Anesthesiologists (ASA) physical status class II or higher. Exclusion Criteria: 1. Newly diagnosed, untreated, or uncontrolled hypertension -in two measurements on the day before surgery Systolic Blood Pressure (SBP) ≥180 mm Hg or Diastolic Blood Pressure (DBP) ≥110 mm Hg 2. Persistent difference in recorded SBP between right and left upper limb \>10 mm Hg 3. Persistent atrial fibrillation 4. Have a documented history of dementia 5. Have language, vision, or hearing impairments that may compromise cognitive assessments 6. Have a condition that precludes routine blood pressure management such as surgeon request for relative hypotension 7. Receiving irreversible nonselective monoamine oxidase inhibitors (e.g. tranylcypromine, phenelzine) within 2 weeks preceding study enrolment 8. The use of tricyclic antidepressants 9. Have Prinzmetal angina 10. Have contraindications to noradrenaline per clinician judgement 11. Noradrenaline infusion started before surgery or plan to use continuous noradrenaline infusion throughout the procedure 12. Treating physician (surgeon/anaesthetist) decides on the necessity of extended continuous hemodynamic monitoring during or after surgery 13. Severe kidney disease (MDRD creatinine clearance \<15 mL/min/1.73m2) or renal replacement therapy 14. End-stage heart failure: defined as NYHA Class IV - severe limitations in daily activity. Patients experience symptoms even while at rest. Mostly bedbound patients. 15. Known severe liver disease: defined as the presence of liver cirrhosis or any of the symptoms of severe liver dysfunction: portal hypertension (esophageal varices, ascites), hepatocellular insufficiency (e.g., jaundice, hepatic encephalopathy) and coagulopathy (prolonged INR/APTT associated with known liver dysfunction). 16. Emergency and urgent surgery defined as performed within 24 hours of sudden illness/unplanned admission to hospital 17. Have previously participated in the trial: patient already took a part in the HYP-NOR trial in the past 18. Pregnant or breastfeeding women.