Bhavna, it's going to be important to keep OV well fed. There are plenty of good sites (OCF among the best) to get recipes for high protein shakes that will go through a feeding tube. Keeping him well hydrated and well fed will help fight the infections, will help him heal the bed sores (Keep him off those, even when he is sitting up in a chair, there are cushions what will keep those places from getting pressure to them). I guess the nurses have told you that he needs to change positions every two hours or so to keep the bedsores from spreading, to keep new ones from forming. This is very important! These are not just aggravations, they are potential sources of infection!
You two are facing a strong adversary in this fight with cancer. Be strong, too!
Best wishes.