An arterial blood gas (ABG) test measures oxygen and carbon dioxide levels in your blood. It also measures your body’s acid-base (pH) level, which is normally balanced when you are healthy.
Arterial blood gas test results may show whether:
Your lungs are getting enough oxygen
Your lungs are removing enough carbon dioxide
Your kidneys are working properly

There are 4 important measuresment to look at

The Normal Values are:
Partial pressure of oxygen (PaO2): 75 to 100 millimeters of mercury (mm Hg)
Partial pressure of carbon dioxide (PaCO2): 35 to 45 mm Hg
Arterial blood pH: 7.35 to 7.45.
Oxygen saturation (SaO2): 94% to 100%