A Sleep paralysis after total knee replacement and arthroplasty – a low dose midazolam recovered mental status: case report

Abstract

Postoperative cognitive dysfunction is common complication of elderly patient. However, postoperative sleep disorder is a very rare complication. Sleep paralysis is a frightening form of paralysis that occurs when a person is suddenly unable to move for a few minutes. A 76-year-old female was scheduled for total knee replacement and arthroplasty. After the operation under general anesthesia, she transferred to postanesthetic care unit (PACU). 10 minutes later, she was stuporous mental status and had irregular breathing pattern. However, patient’s SpO2 and the result of arterial blood gas analysis were within the normal ranges. Although we administrated sugamadex and naloxone in turn, the patient’s status did not improve. After administration of 1mg of midazolam, she recovered her mental status and breathing pattern. She was aware of the event. She felt no discomfort about breathing in PACU. We thought this case was more suitable for sleep paralysis than other psychologic problems.