a person had COPD & ABGS would be respiratory acidosis, if hav ARF they'd be metabolic acidosis. Where would they be if they had both?

That has, not had.

Had is past tense.

Unspecified acidosis.

That would be a mixed acidosis.

When the pH decreases because of an increase in carbonic acid (CO2 dissolved in solution), that is termed a respiratory acidosis. When it decreases because of an inability of the kidneys to buffer the pH, that is termed a metabolic acidosis. When both are found together, that is a mixed acidosis.

You recognize that by matching the pH with the PCO2 and HCO3-. With a low pH you would expect to see an elevated PCO2. If you do, you know there is a respiratory component to that acidosis. If the PCO2 is normal or low you know the source of that acidosis is not respiratory; it's metabolic. That is reflected in a low HCO3-. If the PCO2 is elevated and the HCO3- is low, then neither system is compensating for the other. It is a mixed disorder.
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Huh?