Roy states that the nurse would not let him go to sleep to make sure he would not fall into a coma. Either a patient is stable enough and can safely sleep and his vitals will be monitored, or he is not stable (probably Roy's case) and the ICU or emergency doctor will actually want to put him in an "artificial coma" (i.e. medically induced coma) to enable them to monitor and treat the patient better (common Hollywood mistake called the "stay with me!" or "stay away from the light!" magical medication).