Not as long as he is of sound mind. If there ever comes a time where he cannot make decisions for himself and if there is no one the adequately care for him..it is possible they could place him in a long term care facility. That's why having a power of attorney is so important and you definantly need to make sure he has one asap. I do believe it would take awful lot to get an MD to involuntarily commit someone. But the POA needs established so it would make it less likely to happen.
FYI I am a nurse who visits the I'll and elderly in their homes to keep them out of long term care as long as possible and maybe never even have to go to long term care facilities. I have also done some hospice work. I would strongly recommend that you get in touch with a home healthcare agency in your area. Think it would probably help you a lot. :)