This is Jeff Guy. We're going to continue our series on topics of mechanical ventilation.

We've been doing a series to try to introduce mechanical ventilation to somebody who may not have a whole lot of experience,

or someone who has experience with mechanical ventilation, but it's not exactly sure why we do some of the

little things that we do.

On this talk, I really want to focus on issues regarding ventilation and oxygenation.

Ventilation referring to things such as title volume and the rate and oxygenation,

what is the relationship of FIO2 and PEP and functional residual capacity?

Let's start with ventilation.

When we look at it at arterial blood gas, the things that really we're looking at in regards to ventilation are the PCO2,

the partial pressure of carbon dioxide and the dissolved plasma.

In some regard, the CO2 contributes to the pH.

Now, what stimulates most people to breathe is pH,

not so much of the blood, but of the cerebral spinal fluid.

People who have COPD don't really have a respiratory stimulus in that regard to their

respiratory stimulus is hypoxia.

But when we make changes to a ventilator that we want to change the CO2, we want to make

the CO2 better, or if we want to approve the CO2, somebody's got a CO2 of say 60,

we want to prove the minute ventilation.

Amidant ventilation is defined as the tidal volume times the respiratory rate.

And those are the two things that really affect ventilation.

Now, respiratory rate is, we're pretty comfortable with that is, that's how many times we

breathe in a minute.

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