I wish I could give you some strength right now. This is an area where I have had quite some experience as I've been an RN in a central city hospital for nearly 20 years.
1) Respect the patient's decision. To no longer seek medical treatment after all he has been through is valid. There is much more I could say on this, but you can always email me.
2) Understand that his family and loved ones are probably going to be in different stages of acceptance of his decision.
3) Love them all, because they have not changed, only their present circumstances have.
You don't have to talk about his lack of dialysis or any of the medical stuff. Just be yourself, for they love you for who you are. Bring ordinary news of the outside world. Ordinary is good, for it lends stability and a sense of continuation. Tell him you love him. Let him know what impact he or his family has had directly on your life. Share your favorite memory with him, especially if it's funny. Several opening lines can be:
"Do you know that I always admired it when you _______"
"Do you know that if it weren't for you/or family I would not have__________"
"Do you remember the time when_______" You've got room to find a good story here, especially if you can make him look like a hero. Maybe you and your friend did something not so bright and he bailed you out??? Sometimes laughter is the best medicine, but certainly consider the individual moment when you get there. Using humor in these situations can be very reassuring. It breaks tension, helps make the situation more ordinary and shows that you are comfortable with them even in this very difficult days.
If you have a moment alone with him and if you feel comfortable with this, ask him if there is anything you can do for him. Kneel down at the edge of the bed or his chair and look him straight in the eye when you do it. "Is there something that I can do for you, something you have left undone?" is the phrase I have used. Sometimes there is nothing, but other times there is a simple request.
If all else fails, hugs work.
Regardless of what you do, just being there shows you for the true friend you are. They know that. Being there for the long haul means the world.
Take a deep breath and relax before you walk through those doors. They're still the same people you love. God bless you for being a faithful friend!
PS Email me if you want to talk.
"Unless you're sharing what you have, you don't have as much as you think you do."