The Effect of Noradrenaline Infusion Versus Standard Blood Pressure Management on Perioperative HYPotension in NOn-caRdiac Surgery HYP-NOR Trial

Inclusion Criteria:

1. ≥45 years old

2. Elective or accelerated* non-cardiac surgery expected to last ≥1 hour and requiringgeneral, 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 theday before surgery Systolic Blood Pressure (SBP) ≥180 mm Hg or Diastolic BloodPressure (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 cognitiveassessments

6. Have a condition that precludes routine blood pressure management such as surgeonrequest 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 continuousnoradrenaline infusion throughout the procedure

12. Treating physician (surgeon/anaesthetist) decides on the necessity of extendedcontinuous hemodynamic monitoring during or after surgery

13. Severe kidney disease (MDRD creatinine clearance <15 mL/min/1.73m2) or renalreplacement therapy

14. End-stage heart failure: defined as NYHA Class IV - severe limitations in dailyactivity. 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 thesymptoms of severe liver dysfunction: portal hypertension (esophageal varices,ascites), hepatocellular insufficiency (e.g., jaundice, hepatic encephalopathy) andcoagulopathy (prolonged INR/APTT associated with known liver dysfunction).

16. Emergency and urgent surgery defined as performed within 24 hours of suddenillness/unplanned admission to hospital

17. Have previously participated in the trial: patient already took a part in theHYP-NOR trial in the past

18. Pregnant or breastfeeding women.