What are these behaviors possible signs of?

My Grandpa is 75. He has COPD and is on oxygen, has early stage lung cancer which he had radiation treatment for about a month ago, diabetes, and hearing loss. His father had Parkinson's disease and he has exhibited early signs as well, such as shaking and small messy handwriting. At the moment he has pneumonia and the antibiotics he is taking are not working and it's getting worse and harder to breathe so he decided to go to the hospital tomorrow morning. Since he has had his current infection he has behaved differently. He normally is watching tv or on the computer most of the day, and he has been just sitting in silence for hours and hours. I went to the kitchen at night and he was sitting in his chair, he usually goes to sleep an hour earlier, and he said "relaxing" to me unprompted I hadn't asked what he was doing yet. I looked at him and he was shaking and breathing heavily and looked anything but relaxed. I asked what he meant, he said "relaxing" again and I said "you're relaxing?" "yes" I can't explain it but he just seemed off, not like himself and he wasn't making sense it was like he was in a child like state. The next night I heard his tv was off for several hours (which is unusual for night time) and I eventually go to the living room and he says "help me" I asked if he needed help with his oxygen machine but he said "the tv is broken" I look at the tv and it is just turned off, so I grab the remote and turn it on for him. And he says "Oh I was trying to fix it for so long" and again his demeanor is just not like himself, his gaze seems off and he seems confused. There's been several little moments like this the past week, and it may seem rather banal in writing, because it is hard to articulate the severity of the change in demeanor. It's almost similar to talking to someone who is sleepwalking.

I am mostly wondering what other signs I should be looking out for and what these behaviours could indicate. And also what I should be bringing to the attention of his doctors and the hospital staff, and what is just me being paranoid. My grandpa is hearing impaired and has a stutter, so it is mostly me, my mom, or my grandma talking to the doctors. Are there any questions that come to mind that I should ask the doctors? What are some ways I can better support him when he seems out of it and unlike himself? Should I be talking to him about the changes I've noticed, or will that just make it worse and cause him anxiety? Any insight at all would be helpful honestly. Thanks!