What is it used for?
A blood oxygen level test is used to check how well your lungs are working and measure the acid-base balance in your blood. The test usually includes the following measurements:
Oxygen content (O2CT). This measures the amount of oxygen in the blood.
Oxygen saturation (O2Sat). This measures the amount of hemoglobin in your blood. Hemoglobin is a protein in your red blood cells that carries oxygen from your lungs to the rest of your body.
Partial pressure of oxygen (PaO2). This measures the pressure of oxygen dissolved in the blood. It helps show how well oxygen moves  from your lungs to your bloodstream.
Partial pressure of carbon dioxide (PaCO2). This measures the amount of carbon dioxide in the blood.
pH. This measures the balance of acids and bases in the blood.
