nonrebreather-how long, and what should be next

I need your help about the nonbreather.

This is the Pt's history: an eldrely pt admitted for pneumonia. He was doing fine, A&Ox2, no fever, bed resting, on PEG feeding and 3-4 IV antibiotics. He went for sacral pressure ulce debridement at noon, and around 4 pm he became totally disoriented, eye open for pain, SOB, O2 sat down to 87%. They doc. and day nurse put him on nonrebreather with O2 95-98% and I got him at 7 pm. PEG eeding was D/Ced, dressing was changed which with no bleeding. The only thing was the nonrebreather and slightly labored breathing I thought was problem. I talked to the doc. and called the RN from RRT. They all said O2 sat was fine leave him alone, "call me if he needs to be intubated," the doc said. I did chest pts and suctions, and he was on that nonrebeather with O2 about 95-97%, whenever it was removed O2 will go down to low 80. I knew non rebreather was for short time use, but don't know how short is short.

A Different nurse came for my district for day shift. When he heard the pt was on nonrebreather for about 15 hours, and next step would intubation, he was very angry.

My questions are: how long usually nonbreather used for pts; what else I, as nurse, can do to void nonrebreather or intubation for pt like this; what I can suggest doc to do.

Thank you in advence for your help and sharing you knowledge.