Benzodiazepines are frequently administered for sedation to surgical intensive care unit patients who require postoperative intubation and mechanical ventilation. Midazolam is the most commonly used drug, which is water soluble, short-acting benzodiazepine and rapidly metabolized by the liver. Continuous intravenous infusion of midazolam was administered to the man who was 40 years old for mechanical ventilation in the intensive care unit for 58 hours. After discontinued midazolam, patient who had acute hepatic dysfunction had been sedated with endotracheal intubation for 5 days. Even flumazenil was tried twice to reverse the effect of midazolam, the response was limited by the time. Finally he awaked as recovery of his hepatic function.