It was towards the end of his ordeal with Multiple Myeloma. He fell or collapsed in the bathroom and my mother couldn't really do anything by herself. She called 911 and they sent an ambulance and took him to the hospital and handled the situation really well.
Not sleeping IS an issue when we are caring for someone who is recovering from a surgery or ill. In situations where I've been unable to sleep due to looking after someone very ill, the worst thing is to think, "I've got to sleep" because that makes it much harder to sleep. I tried to nap when I could but I just told myself, "Right now the rules are different and I'm on call all the time" and reminded myself how many other people have been in this exact same situation. Something just pulls you through. My mother lived in a situation like this for three and a half years and somehow got through. There's also the love we feel for these people and maybe the feeling of paying them back for all the good they've done for us, which can make it easier.
Good luck with your situation.