First I am sorry about your grandfather. I know how difficult this is on you and your family.
This situation is common in CCU settings. If anything, families honoring the patients request is more rare. Just this past week we had a patient on home Hospice who's family wanted to go full care. We intubated him, put him on pressors etc. The MD gets their hands tied because in cases where the patient is unable to determine their own care (which he cannot kow) it then defers to the family. She does not need to be a designated POA.
Thinking of your grandfather,and coming from the other side, keeping him alive in this aituation is selfish. His wishes were to pass. Having COPD is like they are suffication- no medical managment can fix it end-stage. Being on a ventilator is also extremely uncomfortable.
One thing you can do is see if they have a palliative care MD that you can speak to. They have a special way of explains things to pts/families that may be more effective than the Intensivist.
I know it's really hard; I'm sorry you are going through this. When my dad died at age 84, it helped to remind myself that this is the way it should be: we live, grow old, and are mourned by our children and grandchildren. I tried to remember that it's sad, very sad, when an elderly person dies, but it's not a tragedy. It's the natural order of things.
Your grandfather is lucky to have you and so many other family members who love him so much. I'm sorry you are struggling with this decision.
I am so sorry This is incredibly tough, but at the end of the day you and your family have to remember it is about your grandpa and how he wanted the end of his life to go. My Gram was DNR and received amazing hospice care in her home. Honestly, those nurses were angels on earth and treated my Gram with such respect and care and for us, they helped us through an incredibly difficult time.
Please stand up for your Grandpa if he is not able to do so now. I understand the feeling that there is never a good time, it will never feel like you have had enough time with the person you love, how can there be, but at the very least you can make sure he is going on his terms, surrounded by all who love him. THAT is an amazing gift to give.