There is truly one thing that makes a significant difference for your loved one and that is water. I always know when my loved one hasn’t had enough water as the next day they will not be well. Elderly people are not fond of drinking a lot of water, so it’s your job and my job to help them drink enough. It is night and day different. If my loved one doesn’t get enough water, I know that it will be a bad day the next day. And that affects everyone.
So water, water, water. Not tea, coffee, soda, whatever. Have them sip water continuously.