The Choice of Vasopressor to Prevent Postoperative Acute Kidney Injury After Major Non-Cardiac Surgery

VEGA-2 is an open-label, pragmatic, multiple periods, cluster-randomized, crossover trial across hospitals from MPOG. Hospital centers will be assigned to use either phenylephrine (PE) or norepinephrine (NE) for the first-line intravenous vasopressor in the operating room for the treatment of intraoperative hypotension. Centers will be randomly assigned to use PE during even-numbered months and NE during odd-numbered months, or vice versa. Data will be collected from routine clinical care and automatically extracted from the electronic health record. No additional lab tests or procedures will be required for the study. Only the randomization (of each hospital to the sequence of interventions) will be different from usual care.

The intervention is the first line vasopressor used for both infusion and bolus dosing, either PE or NE . Anesthesia providers will use the concentration that their respective center already uses in line with local anesthesia and pharmacy standard operating procedures. Anesthesiologists will provide standard of care during the intraoperative period. They will evaluate the need for vasopressors based on hemodynamic assessment and the arterial pressure goals during the procedure. Anesthesia providers will be encouraged to maintain mean arterial pressure above 65 mmHg or within 20% from baseline, but the arterial pressure targets can be adjusted on an individual basis, for instance during pre-surgical time-out, or based on individual assessment. Doses of bolus or continuous infusion of vasopressors will be adjusted to reach these goals on an individual basis. Of note, the anesthesia provider could use the alternative vasopressor if they consider the benefit of one drug being higher. A second line vasopressor will be allowed. The choice of the first line vasopressors will be determined by the randomization block.

Inclusion criteria

• Age 18 years or older
• Surgery under general anesthesia with a surgery duration of 2 hours or more
• Received intravenous vasopressors during surgery

Exclusion criteria

• Cardiac surgery
• Extra-corporeal membrane oxygenation
• Organ transplantation
• Obstetric procedures
• Procedures on the kidney
• Outpatient procedures
• Already receiving NE or PE or inotropes before induction of anesthesia (at the time of anesthesia start)
• American Society of Anesthesiologists physical status classification 5 or 6
• Patient for whom a local protocol recommends a specific first line vasopressor
• Most recent documented estimated glomerular filtration rate (eGFR) < 15 mL/min/1.73m^2 or preoperative renal replacement therapy within 60 days before surgery
• Patients who do not have a preoperative creatinine value within 60 days before surgery
• Alive patients who do not have a postoperative creatinine value