I'm very sorry to hear that. A physician friend of mine in another state said that in her hospital, nobody in my uncle's age range (80s) that she knows about has survived the ventilator. It's an awful decision to have to make, and I'm sorry that anyone has to. I hope they can keep your uncle relatively comfortable.
That sounds about as bad as it can be. Even after the virus is gone, it makes such a mess that getting everything back in some semblance of order can take the body quite a while. I really hope you get some good news soon.
My uncle was worse Sunday morning. His oxygen saturation was back in the 80s. A neighbor who had COVID a couple of months ago stopped in to check on him and just happened to bring an oxygen tank along. The neighbor convinced him to go to the ER, and I think even drove my uncle. ("Neighbor" is accurate, but the word really doesn't do justice to the longstanding connection between our families. I've personally known five generations of this family, one of whom taught my dad to shoot and left me the M1 Garand that is my gun safe right now.) In any case, there were no hospital beds to be had nearby, so he got a three hour ambulance ride across state. I don't know how long he'll be there or what his status is now. Earlier today there was mention of convalescent plasma or remdesivir or some other treatment. As far as I know, my aunt is not symptomatic yet. It'll be a miracle if she doesn't get sick too. Her daughter and son-in-law are enroute now, and I'm hopeful that they can positively affect the situation and ease the decision fatigue of her parents.