Acute hyperactive delirium-like episode during dexmedetomidine sedation after recent discontinuation of long-term reserpine therapy: a case report.

Background: Dexmedetomidine is a commonly used perioperative sedative and is generally associated with a lower risk of postoperative delirium; however, a few cases suggest that it may also cause delirium-like neuropsychiatric reactions in certain patients. Although reserpine is used less frequently, the changes in central neurotransmitters after long-term exposure and recent discontinuation remain a concern. At present, there are no reports of acute behavioral abnormalities in patients who received dexmedetomidine sedation perioperatively after recent discontinuation of long-term reserpine treatment. Case presentation: A 63-year-old hypertensive woman, who had been taking reserpine for 10 years and discontinued it 7 days prior to surgery, underwent arthroscopic meniscectomy under subarachnoid anesthesia. After satisfactory anesthesia, she was given intravenous dexmedetomidine for stress sedation. During the infusion, the patient suddenly experienced disorientation, incoherent speech, significant resistance, and agitation, accompanied by a further increase in blood pressure. Immediately after an intravenous bolus of remimazolam 2 mg, the symptoms rapidly subsided, the patient returned to a sedated state, and the surgery was successfully completed. Postoperatively, the patient was conscious, did not exhibit similar abnormal behavior, had no recollection of the episode, and was discharged smoothly on the 3rd postoperative day. Conclusion: This case suggests that rare acute hyperactive delirium-like episodes may occur in patients who have recently discontinued long-term reserpine therapy and are receiving dexmedetomidine sedation during the perioperative period. Clinically, careful titration and close monitoring of mental status and hemodynamics are necessary.