A Case Report on an Unknown Etiology Disorder of Consciousness Following Extubation Despite Thorough Evaluation

Postoperative disorders of consciousness can arise from various factors, making diagnosis challenging. This report presents a case of a disorder of consciousness that occurred after awakening from general anesthesia, in which various examinations including computed tomography (CT) and magnetic resonance imaging (MRI) were conducted, but the cause could not be identified. A man in his 60s with a history of hypertension and cerebral hemorrhage underwent revision total hip arthroplasty under general anesthesia for a left periprosthetic hip fracture. The induction and maintenance of anesthesia were uneventful. Postoperatively, anesthesia was discontinued, and the patient responded to verbal commands, opened his eyes, and was able to follow handgrip instructions, allowing for extubation. However, after moving to the recovery room, his level of consciousness decreased, reaching a Glasgow Coma Scale score of E3V1M3-4. Suspecting prolonged effects of the anesthetic agents, his condition was observed in the recovery room for approximately 30 minutes, but there was no change in his level of consciousness. CT and MRI of the head were performed, but no significant abnormalities were found. Electroencephalogram monitoring did not show any clear epileptiform activity. Gradual improvement in his level of consciousness was noted 60-120 minutes after the initial decline. Subsequently, there were no further episodes of disordered consciousness. Perioperative disorders of consciousness are challenging to diagnose due to the potential effects of anesthetic agents. Although the cause could not be identified in this case, the patient fortunately recovered consciousness without any significant sequelae.