BACKGROUND:Patients presenting for surgery with angiotensin axis blockade (AAB) from therapy with either angiotensin-converting enzyme inhibitors or angiotensin receptor blockers experience an increased incidence of perioperative hypotension. Acute kidney injury (AKI) in patients receiving preoperative AAB has been demonstrated after lung, vascular, and cardiac surgery. However, there is little literature evaluating the hypotensive and renal effects of preoperative AAB and major orthopedic surgery.