PO2 and aging????

Posted
by qaqueen qaqueen Member Nurse

Has 10 years experience.

I have read several articles, with opposing statements about PO2 and aging.

My understanding is that PO2 decreases with age. I have seen different formulas for calculating the PO2 reduction, that basically end up with the same value.

The simplest formula l have seen is:

Normal PaO2 (at sea level)= 100 mm Hg - the number if years over age 40.

So, my question is, if you have an 98 year old DNI patient with a pulse oximeter readings > 92% on 2 liters via nasal cannula and a PO2 of 54, would you increase the O2 flow? Would it increase the PO2?

According to the above formula, PO2 of 42 would be okay.

Thanks for your help.

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1,385 Posts

It isn't a linear progression. It is a function of a lot of factors, not the least of which is lung volume decreases with age, so, no, a PaO2 of 42 would not be OK. If this is for a test, I have no idea what the answer would be, but in actual practice, in this situation, I'd titrate for greater than whatever saturation you chose and ignore the PO2.

qaqueen

qaqueen

Has 10 years experience. 308 Posts

Not for a test í ½í¸€. The pt had atelectasis and infiltrates. At 2 liters, saturation was 93-98%. Colleague thought patient should be on high flow to improve PO2. I was concerned with overdoing the O2.

qaqueen

qaqueen

Has 10 years experience. 308 Posts

í ½í¸€ that was a smiley face on my phone

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1,385 Posts

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Just check the PO2 on the x with the SaO2 on the y. At the end of the day, that'll be what you need, funky patient presentations aside...