Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.
For general information about clinical research, read Learn About Studies.
Eligibility Criteria
- * At least 45 years old;
- * Scheduled for major noncardiac surgery expected to last at least 2 hours;
- * Having general anesthesia, neuraxial anesthesia, or the combination;
- * Expected to require at least overnight hospitalization (planned ICU admission is acceptable);
- * Are designated ASA physical status 2-4 (ranging from mild systemic disease through severe systemic disease that is a constant threat to life);
- * Chronically taking at least one anti-hypertensive medication;
- * Expected to have direct intraoperative blood pressure monitoring with an arterial catheter;
- * Cared for by clinicians willing to follow the GUARDIAN protocol;
- * Subject to at least one of the following risk factors:
- * Age \>65 years;
- * History of peripheral arterial surgery;
- * History of coronary artery disease;
- * History of stroke or transient ischemic attack;
- * Serum creatinine \>175 µmol/L (\>2.0 mg/dl);
- * Diabetes requiring medication;
- * Current smoking or 15 pack-year history of smoking tobacco;
- * Scheduled for major vascular surgery;
- * Body mass index ≥35 kg/m2;
- * Preoperative high-sensitivity troponin T \>14 ng/L or troponin I equivalent, defined as ≥15 ng/L (Abbott assay),77 19 ng/L (Siemens assay, \[Borges, unpublished\]), or 25% of the 99% percentile for other assays;
- * B-type natriuretic protein (BNP) \>80 ng/L or N-terminal B-type natriuretic protein (NT-ProBNP) \>200 ng/L.78,79
- * Are scheduled for carotid artery surgery;
- * Are scheduled for intracranial surgery;
- * Are scheduled for partial or complete nephrectomy;
- * Are scheduled for pheochromocytoma surgery;
- * Are scheduled for liver transplantation;
- * Require preoperative intravenous vasoactive medications;
- * Have a condition that precludes routine or tight blood pressure management such as surgeon request for relative hypotension;
- * Require beach-chair positioning;
- * Have end-stage renal disease requiring dialysis or estimated glomerular filtration rate (eGFR) \<30 ml/min;
- * Have a documented history of dementia;
- * Have language, vision, or hearing impairments that may compromise cognitive assessments;
- * Have contraindications to norepinephrine or phenylephrine per clinician judgement;
- * Have previously participated in this trial.
Ages Eligible for Study
45 Years to
Sexes Eligible for Study
ALL
Accepts Healthy Volunteers
No