I was to draw a blood gas on a patient the other day on Room Air. So I put the patient on Room Air and told the nurse I would be back in about 20minutes to draw the gas. She told me she went to a seminar last week, and was told that, the new standard on the wait for O2 stabilization was now about 5 minutes. Of course, I waited my 20 mins, but, .....Has anybody heard of this?
Thanks
Barry

As far as I know all the leading respiratory publications and guidelines (kaczmerack and others) state you must wait 20 minutes between FIO2 changes.

I seem to remember that in a patient with stellar cardiac and pulmonary systems, a 3 minute wait is enough time for any change to equillibrate through both systems.

But if someone has the worst imaginable cardiac AND pulmonary system then the time for the oxygen change to "go round the bend" for both systems could be as much as 40 minutes.

Someone with severe COPD would take longer for the O2 to equillibrate in the lungs. And with the worst heart disease the subsequent time for any PaO2 change to then stabilize a PvO2 would also be much longer.