PHEnylephrine versus NOrepinephrine in Major NONcardiac surgery (PHENOMeNON): Foundational Studies for a Pragmatic Randomized Clinical Trial. - ABSTRACT BACKGROUND: Approximately 60,000 patients undergo procedures requiring general anesthesia daily in the U.S., 60% of which require the administration of intravenous vasopressors to counteract general anesthesia- induced cardiovascular depression and low blood pressure (hypotension). Many studies have established the harmful effects of intraoperative hypotension, including myocardial injury, stroke, and acute kidney injury. Vasopressor therapies to treat intraoperative hypotension, specifically the choice between norepinephrine and phenylephrine, are debated vigorously. More studies are needed to better understand vasopressor selection and use and the impact of vasopressor selection on end-organ perfusion outcomes. RESEARCH: The goal of the proposed research is to conduct foundational studies to obtain essential background data and to conduct a pilot clinical trial. The first specific Aim is to perform a quantitative assessment of vasopressor practice patterns and variation across multiple institutions. This data will guide the sampling strategy of Aim 2, which explores attitudes and opinions of clinicians surrounding vasopressor selection at multiple institutions with a mixed methods approach. Aims 1 and 2 inform protocol development of a pilot study which allocates either norepinephrine or phenylephrine as the first-line vasopressor to be used to treat intraoperative hypotension conducted at the University of Michigan (UM) in Aim 3. The proposed research and training will provide Dr. Janda with the skills required to transition to an independent researcher. CANDIDATE: Dr. Allison Janda is a cardiothoracic anesthesiologist with board certification in anesthesiology and advanced perioperative echocardiography at UM. Through completion of a T32 Research Fellowship, Dr. Janda has begun to develop expertise in perioperative outcomes research, assessments of practice variation and clinical trials design. Her long-term career goal is to improve care for patients undergoing cardiac and major, non-cardiac surgery by better understanding and avoiding perioperative end-organ injury. ENVIRONMENT: UM is the coordinating center for the Multicenter Perioperative Outcomes Group (MPOG), an international consortium of over 50 institutions with perioperative information systems. Dr. Sachin Kheterpal, MD, MBA is a co-primary mentor for Dr. Janda, and is the Director for MPOG and member of the NIH Precision Medicine Initiative Advisory Panel. Dr. Daniel Clauw, MD is Dr. Janda’s other co-primary mentor and is the director of the Chronic Pain and Fatigue Research Center and founding director of the Michigan Institute for Clinical and Health Research. The proposed research will be completed under the guidance of her co-primary mentors, co-mentors including Dr. Michael Fetters, MD, and Dr. Graciela Mentz, PhD, and an advisory panel of experts in EHR data research, mixed methods research, and clinical trials.