What it means
A sample of blood taken from an artery, most often the radial artery at the wrist. It shows how well the lungs move oxygen in and carbon dioxide out, and whether the blood is too acidic or too alkaline. The pH, PaCO2 and HCO3- together tell whether a problem is respiratory or metabolic.
For the nurse
Before a radial sample, check that the hand has blood flow from the ulnar artery too (the Allen test). After the draw, press on the site for at least 5 minutes, longer for a client on an anticoagulantan-tee-koh-AG-yoo-luntA drug that slows the blood's ability to form clots.anti- againstcoagul/o clotting-ant an agent that doesFull entry , and send the sample on ice if the lab asks for it.
Remember it
ROME: Respiratory Opposite (pH and CO2 move in opposite directions), Metabolic Equal (pH and HCO3- move together).
At a glance
| Normal range | pH 7.35–7.45; PaCO2 35–45 mm Hg [4.7–6.0 kPa]; HCO3- 22–26 mEq/L [22–26 mmol/L]; PaO2 80–100 mm Hg [10.7–13.3 kPa]; SaO2 95–100% |
|---|---|
| Critical range | pH below 7.25 or above 7.55; PaCO2 below 20 or above 60 mm Hg; HCO3- below 15 or above 40 mEq/L; PaO2 below 40 mm Hg; each lab sets its own critical values. |
| Abbreviations | ABG; PaO2, PaCO2, HCO3-, SaO2 |
| Spanish | gasometría arterial |
| Also written | arterial blood gases, ABG, ABGs |
Related terms
pulse oximetry
A painless test that uses light through a finger, toe or earlobe to estimate how much oxygen the blood is carrying.
oxygenation
The process of getting oxygen into the blood and delivering it to the body's tissues.
hypoxemia
A level of oxygen in the blood below normal.