Abstract
RATIONALE: Angiotensin II receptor blockers (ARBs) are currently considered first-line antihypertensive drugs, effectively inhibiting the renin-angiotensin-aldosterone system. However, ARBs have been associated with intraoperative hypotension during general anesthesia. Although it is recommended to discontinue ARBs for 24 hours before surgery, the optimal duration of discontinuation remains unclear. We present a severe refractory hypotension encountered during general anesthesia despite discontinuing ARBs for 48 hours before anesthesia. PATIENT CONCERNS: A severe refractory hypotension occurred during the induction of general anesthesia for cranioplasty in a 66-year-old male patient (170 cm/75 kg). The patient was taking azilsartan, angiotensin receptor blocker, for hypertension, which was discontinued 48 hours before anesthesia induction. Despite repeated administration of ephedrine and continuous infusion of norepinephrine, hemodynamic instability did not improve. Therefore, the surgery was postponed. DIAGNOSIS: The patient was diagnosed with angiotensin receptor blocker-induced refractory hypotension. INTERVENTIONS: Before the second surgery, the angiotensin receptor blocker was discontinued 96 hours prior to the surgery. Invasive blood pressure monitoring was performed before anesthesia induction, and vasopressin was prepared. General anesthesia was induced using remimazolam and maintained with desflurane. OUTCOMES: The surgery was completed successfully without occurrence of refractory hypotension. LESSONS: Refractory hypotension induced by Angiotensin receptor blockers can still occur even after discontinuing the medication for 48 hours before induction of general anesthesia. Despite withholding the medication, caution should be practiced regarding hypotension during general anesthesia in patient taking ARBs.