My father is 80 years old. 5 days ago (Monday), he had surgery to address a chronic subdural hematoma (400cc of liquid/blood). Burrhole on both sides of his head. Tubes were removed Wednesday. He didn t wake up on Wednesday so on Thursday, NGT for 250 calories, every 4 hours. Friday am, CT scan revealed a blood clot on his right side (100 cc), another burrhole. My question is, what can be the possible reasons why he is not waking up? Both neurosurgeon and neurologist , after reviewing his CT scan say that they see no reason why he is not waking up and that we should just wait.