This is the podcast, ICU rounds.

My name is Dr. Jeffrey Guy.

I'm an associate professor of surgery and director of the Burns Center at the Vanderbilt University School of Medicine in Nashville, Tennessee.

Welcome back to ICU rounds.

I've had several emails to approach the topic of the interpretation of arterial blood gases.

And this is something that I can certainly admit that when I was in medical school

and even as a junior resident approaching interpretation of blood gases was somewhat daunting.

And now as I keep giving the development of this topic more and more thought

in my opinion it's now almost like riding a bike how do you tell somebody to ride a bike

when I'm at the bedside of somebody and I'm looking at their blood gases but one of the

things that seems to make make sense when teaching this this topic is that we have to probably

first really delve into some of the issues of hypoxia,

which we've done in an earlier podcast, and then also talk about the role of pulse oxymetry.

A lot of the classic lectures or classic textbook chapters in arterial blood gases really predate

pulse oxymetry, which to many of you may seem really kind of unbelievable that oxymetry or

continuous pulse oxymetry is a reasonably new instrument in the care of the critically

injured or a critically ill patient. Now, when we look at the blood gas, there are several variables

that we're looking at. There's the pH, the PC CO2, the PO2, and the saturation, as well as a total hemoglobin.

And we've talked in other podcasts.

We have to think of a little bit about how the body is designed to carry oxygen around the body.

That we have oxygen that is dissolved in the plasma, and that represents the partial pressure of oxygen.

When you think about how a fish is able to breathe in water, a fish is able to breathe in water because there is oxygen dissolved in that water to a certain degree.

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