EVERYONE intubated receives 100% Oxygen initially. Usually once the ventilator is set, an ABG (arterial blood gas) is drawn after perhaps 30 minutes, but it can be sooner. The values there will almost always show elevated O2 levels and possibly lower CO2 numbers. Adjustments are made based on the ABG.
Most intubated/ventilated Patients are placed on ‘vanilla settings’ and the tweaking begins once the ventilation status is determined. Everybody is different, but rare is the one who requires 100% delivered Oxygen. CO (Carbon Monoxide) or CO2 poisoning would be those such, but not exclusively.
Brain death can be determined in more than 1 way. A brain scan or an ‘Apnea Test’ are most common. I once took a Patient for a brain scan. He was fit looking, mid 30s, ventilated. I returned him to the ICU and went to do my reporting on my computer. I saw at once that he was declared via computer deceased WHILE I HAD HIM IN THE ELEVATOR. No Physician even looked at him. I was out of my mind with fury. I put him back on his regular ( to travel) vent and the family was present. A few minutes following, I heard screaming from a conference room. It was all handled so inappropriately that I was staggered.
This situation is being managed likely by Hospital Administration with major federal government input.
I am reluctant to comment more on this case. I simply do not know enough about it. I just have my own anecdotal experiences.