My father is in his fourth year with pulminary fibrosis. He now is mostly bedridden, with oxygen saturation at 90 while at rest, but low 80s when doing 'light' activity such as using pooing. He uses using 4 liters of oxygen per minute. He is getting weaker now, less appetite, more confused, and had started to burp more. (1) What does the increased burping signify? (2) is he most likely to pass on from not getting enough oxygen, from not getting the carbon dioxide out of his system, or both? (3) does knowing that helps us prepare him? (4) what are signs that we may only have weeks left? Anything that you can share is appreciated greatly. Thank you.