An arterial blood gas (ABG) test measures the acidity (ph) and the levels of oxygen and carbon dioxide in the blood from an artery.
This test is used to check how well your lungs are able to move oxygen into the blood and remove carbon dioxide from the blood.As blood passes through your lungs, oxygen moves into the blood while
carbon dioxide moves out of the blood into the lungs. An ABG test uses blood drawn from an artery, where the oxygen and carbon
dioxide levels can be measured before they enter body tissues.
What an Arterial Blood Gas Measures:
- Partial pressure of oxygen (PaO2). This measures the pressure of oxygen dissolved in the blood and
how well oxygen is able to move from the airspace of the lungs into the blood.
pressure of carbon dioxide (PaCO2). This
measures how much carbon dioxide is dissolved in the blood and how well carbon dioxide is able to move out of the body.
- pH. The pH measures
hydrogen ions (H+) in blood. The pH of blood is usually between 7.35 and 7.45. A pH of less than 7.0 is called acid and a
pH greater than 7.0 is called basic (alkaline). So blood is slightly basic.
- Bicarbonate (HCO3). Bicarbonate is a chemical (buffer) that keeps the pH of blood from becoming too acidic or too basic.
- Oxygen content (O2CT) and oxygen saturation (O2Sat) values. O2 content measures the amount of oxygen in the blood. Oxygen
saturation measures how much of the hemoglobin in the red blood cells is carrying oxygen (O2).