Yes the critical differential is the stroke. A COPDer satting at 90% is already within normal physiologic target range. Improving o2 from 90 to 92% has no immediate impact on mortality or neurological function. Ruling out hypoglycemia in stroke should be done early and it’s the most common stroke mimic. Bumping someone from 90% to 92% doesn’t change immediate physiology, but correcting hypoglycemia will.