Not much I can suggest unless you try a humidifier but this does not sound good. Don't you have an ER clinic or aVet on call?
This sounds serious and not sure what you can do at home as the dog probably needs oxygen, a diuretic, etc that only a Vet can do. You have meds?
Maybe someone has an idea but it is late now
Hope you have found some improvement.
You say meds to help with heart and lungs. As a human I am unaware of any meds that help one intake oxygen. Supplemental oxygen, yes. I suppose there are some meds to help relax the body which may help, don't know.
I'd look for an emergency pet service, and the facts may point to the need to end the suffering.
Hope they sought Vet help. If fluid build up the dog needs diuretics to help get rid of the fluid, possible heart and other medications plus oxygen.
More than likely, this dog did not survive.....Once they get to the stage she described, the dog is suffocating in it's own lung fluids.....Death is fairly quick (A few hours) without Emergency intervention....Hope she found an Emergency Clinic! :(
I know. I hope so too. :-(