Shook, if I’m reading your post correctly, a catatonic person is unable to eat, drink, speak, or otherwise communicate. If you do nothing they die. Therefore, it’s up to “them”, like medical personnel to make decisions for the person. If there’s family available or willing to assist, I imagine you talk to them. If the person has some sort of legal document telling you NOT to treat them, that’s one thing. Otherwise, you’re obligated to treat them. Unfortunately, if you elect NOT to treat them based on a legal document, it’s possible the person’s family will later sue you for NOT treating someone who wasn’t in their right mind to make that directive. It’s enough to make your head explode. Once the person is able to communicate, at that point you can discuss treatment options.