What it means
Part of an arterial blood gasar-TEER-ee-ul BLUD GASA blood test from an artery that measures oxygen, carbon dioxide, bicarbonate and the blood's pH.Full entry result that shows how well the lungs are removing carbon dioxide. Carbon dioxide forms acid in the blood, so the PaCO2 is the "respiratory" part of acid-base balance. A high level, from breathing too slowly or shallowly, points to respiratory acidosisRES-pur-uh-tor-ee as-ih-DOH-sisA state in which the blood becomes too acidic because the lungs do not remove enough carbon dioxide.Full entry ; a low level, from breathing too fast or deep, points to respiratory alkalosisRES-per-uh-tor-ee al-kuh-LOH-sisAn acid-base imbalance in which breathing out too much carbon dioxide makes the blood too alkaline.alkal base-osis abnormal conditionFull entry .
Remember it
CO2 acts as an acid: more CO2, more acid.
At a glance
| Normal range | 35–45 mm Hg [4.7–6.0 kPa] |
|---|---|
| Also written | PaCO₂, partial pressure of carbon dioxide, arterial carbon dioxide |
Related terms
arterial blood gas
A blood test from an artery that measures oxygen, carbon dioxide, bicarbonate and the blood's pH.
saturation
How full something is; in nursing, usually the percentage of hemoglobin in the blood that is carrying oxygen.
respiratory acidosis
A state in which the blood becomes too acidic because the lungs do not remove enough carbon dioxide.
respiratory alkalosis
An acid-base imbalance in which breathing out too much carbon dioxide makes the blood too alkaline.