Angiotensin receptor blockers (ARBs) are widely used to treat hypertension, but severe refractory hypotension during general anesthesia is a well-known complication associated with the continuation of ARBs during the perioperative period. It has therefore been recommended that ARBs be withheld for 24 hours before induction of general anesthesia. However, impaired renal function affects the pharmacokinetics of each ARB differently. The half-life of azilsartan is prolonged in accordance with the degree of renal impairment. Herein, we describe a patient with chronic kidney disease grade 3B who experienced severe refractory hypotension after induction of general anesthesia requiring administration of dopamine following inadequate responses to ephedrine and phenylephrine despite a 24-hour azilsartan washout period. When the same patient underwent general anesthesia for a subsequent surgery, azilsartan was withheld for 48 hours before induction, resulting in mild intraoperative hypotension that responded adequately to phenylephrine. Severe refractory hypotension during general anesthesia cannot always be avoided by holding azilsartan for 24 hours in patients with significant renal impairment. Therefore, a longer washout period may be preferable for patients regularly taking azilsartan who also have concurrent substantial renal impairment.
Keywords: Angiotensin receptor blocker; Azilsartan; General anesthesia; Refractory hypotension; Renal impairment; Washout period.
© 2021 by the American Dental Society of Anesthesiology.