My late Father suffered complete renal failure while in hospital. He had multiple organ failure from pancreatic cancer. His catheter bag was filled with brown tar like liquid (oxidised blood)
We were told he would not come out of his coma and had only hours to live because of multiple organ failure.
His bed was inclined and his massive swollen legs shrank as his kidney function recovered. He came out of the coma and went home, living an active 8 months longer.