All right, this is episode 421 of the Divine Intervention Podcast. In today's

podcast, we'll continue our pulmonary path of physiology series. This is going to be

series 11. We're going to stop right where we left. So last time we met, we said that at least that's in

episode 319. We said that when you're talking about EE gradient you can have hypoxemia with a normal EE gradient and hypoxemia with an elevated EE gradient with a high EE gradient.

And I give you one central principle I said that whenever you have a problem that is intrinsic to the lungs,

when you have hypoxemia as a result of it, you're going to have an increased a-e-e-e-gredient. On the flip side, when you have a problem that is extrinsic to

the lungs, you're going to have hypoxemia with a normal EE gradient. And I remember the last time we talked about this hypoxemia we spent some time

delineating normal a-a-gredients and you know what makes sense. Now let's talk about hypoxymia with a high a gradient.

So again as I said hypoxymia with a high a gradient means there's a problem that is

intrinsic a problem that is native to the lungs. Now to go a little

deeper on that concept you can think of hypoximil at a high AA gradient being

indicative of a problem in the alveoli or in the pulmonary vasculature.

If you really think about it, the two underlying principles behind most causes of hypoxemia

with a high a- or either you having problems

you know getting the oxygen already in the alveoli into the pulmonary vessel so

the oxygen is in the alveoli. But man for some reason

it just cannot get into the pulmonary vessels into the pulmonary capillary capillary

so your PB-G-O-2 cannot be transformed adequately to P.O2. The other cause of hypoximil or the high A-A gradient or in terms of mechanism is if the blood

skips the well ventilated alveoli altogether.

So you have blood and for some reason,

it just doesn't contact the alveoli,

the well ventilated alveoli.

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