Okay. As we get into interpreting ABG results, it's going to be really important for you to know
the three key components that you need to look at when doing your interpretation
and what the significance of higher or lower values means.
So we talked in my previous video about the normal ranges of these different components,
but let's now go a step further and talk about what it means when they're high or low.
So with the pH, pH should be between 7.35 and 7.45.
If it is under 7.35, that means we have acidosis.
If it is over 7.45, that means we have alkalosis present.
Then when we look at PaCO2, which really represents the respiratory system,
if we find that PaCO2 is below 35, so remember PaCO2 should be between 35 and 45.
If it is below 35, that means we have respiratory alkalosis present,
or it could mean that the respiratory system is compensating for metabolic acidosis.
If PaCO2 is over 45, that means we have respiratory acidosis,
but it could also mean that the respiratory system is compensating for metabolic alkalosis.
And then finally when we look at bicarb, which is HCO3, it kind of represents the metabolic system,
it should be between 22 and 26. However, if HCO3 is under 22,
that means we have metabolic acidosis, or it means the metabolic system is
compensating for respiratory alkalosis. If HCO3 is over 26, this means we have
metabolic alkalosis or it also could mean that the metabolic system is compensating for respiratory
acidosis. And we're going to go through a lot more examples and break this down even more.
If for some reason you're given a pH that is within normal range as well as the PaCO2
and the HCO3, if they're all within the expected ranges, that means we have homeostasis. The chance
of you getting an ABG interpretation problem with all three of these values
within the normal ranges is pretty small. But if you do, that's definitely cause for celebration.
So as we are interpreting ABGs, we're going to use a three-step process.
The first step is we're going to look at the pH and see whether acidosis or alkalosis is present.
The second step is if we have acidosis or alkalosis present,
who is to blame? Is the respiratory system to blame or is the metabolic system to blame?
And then the third step is to see whether compensation is happening. If the respiratory
system is acting out and causing either respiratory acidosis or respiratory alkalosis,
is the metabolic system trying to come in and save the day? Are they trying to
compensate for that respiratory system acting up? Or vice-versa. If we have metabolic acidosis
or metabolic alkalosis, is the respiratory system trying to compensate and save the day?
So that is the third step. Is compensation occurring, and do we have no compensation,
partial compensation, or full compensation? So in the coming videos, we will go through
each acid/base imbalance and look at the different values
to be able to very easily and accurately tell whether we have acidosis or alkalosis, respiratory
or metabolic acidosis or alkalosis, and whether we have full, partial, or no compensation going on.