How to decipher metabolic acidosis from respiratory acidosis?

Metabolic acidosis:

• Low blood pH

• Low bicarbonate

• Normal or low PaCO2

Respiratory acidosis:

• Low blood pH

• High bicarbonate

• High PaCO2

* Additional clinical clues:

- Metabolic acidosis: Diarrhea, vomiting, renal failure

- Respiratory acidosis:COPD, asthma, pneumonia