Need advice

My father had a triple bypass 3 weeks ago and is still in the hospital recovering. He has had some complications post surgery. He has a lot of fluid built up in his feet and lungs. His heart is still weak and his pumping is still not optimum.

The doctors have put him on a ventilator ever since the surgery and he is still not able to breathe on his own. He had some minor infection in lungs , which I believe is now cleared up. He had secretions in his lungs which were also cleared up through a procedure. 

Some days he makes some progresses and breathes for 2 h on his own. Some days he is able to breathe for upto 5 h. But, the doctors say that they are not hopeful that he will be ever able to breathe without a ventilator ever. I am not sure what to do about it? Is there something that I can ask them to do ? I am really worried about his condition and very concerned about him getting back to his normal life.

 Any advice is appreciated.