Your father seems to have developed infection of some sort. Considering the fact he has had a recent surgery, my assumption would be post surgical infection and this is an emergency as he might be developing sepsis where infection can get in to the blood stream. High blood sugars are because of the infection. My suggestion is to get back to the hospital where he has had the surgery and get him admitted to have appropriate treatment of his infection and high blood sugars. Speak to the surgeon who performed the operation and he should be able to help.