[Prevention of Postoperative Delirium and Agitation in a Patient with Anti-NMDA Receptor Encephalitis: A Case Report]

A 41-year-old woman with anti-N-methyl-D-aspartate (NMDA) receptor encephalitis, characterized by vari- ous psychiatric disturbances, was scheduled for laparo- scopic salpingo-oophorectomy. Anesthesia was induced with fentanyl, propofol and rocuronium, and maintained with intravenous propofol combined with epidural anesthesia (T10-11). The patient received 20 mEq of MgSO4 after induction. MgSO4 administrations were repeated at the end of surgery and every 12 hours for 48 hours after the operation. The operation was per- formed successfully, without any troubles. Trachea was extubated in the operating room. The cognitive dys- function was not observed postoperatively. There was no complication and no unexpected event postopera- tively. One month after surgery, the patient's clinical symptom began to improve. The resection of tumor is recommended as a thera- peutic treatment ; however, there has been few report of the management of postoperative cognitive dysfunc- tion for patients with NMDA receptor antibodies. These patients were more likely to experience a post- operative cognitive dysfunction associated with a poor outcome. We, therefore, administered magnesium sul- fate, NMDA antagonist to prevent postoperative delir- ium. In the present case, magnesium sulfate might have prevented the incidence of postoperative delirium without any complications. The prophylactic magne- sium administration could prevent postoperative delir- ium and agitation safely.