Polysomnography during critical illness.

48-year-old man with necrotizing fasciitis, acute renal failure, and post-operative from multiple surgical debridement of bi- lateral lower extremities underwent polysomnography as part of a research protocol. The patient was undergoing mechanical venti- lation and was receiving continuous infusion of sedatives and nar- cotics for comfort. Intravenous midazolam at 5 mg per hour and fentanyl at 75 micrograms per hour were being administered with a Ramsay sedation level of 2. On examination, the patient had anasarca; he appeared sedated and calm while breathing with the assistance of the ventilator. Cardiovascular examination revealed normal heart sounds and no murmurs, while respiratory examina- tion revealed coarse crackles in the base of the lungs. Abdominal examination was benign except for abdominal wall edema and both legs were in surgical dressings. The patient was arousable but was unable to follow commands. Laboratory examination was abnormal with elevated white cell count and serum creatinine levels, and a metabolic acidosis. A representative segment of his polysomnogram is shown below (figure 1).