Levels of oxygen and carbon dioxide in the blood.

A test that determines the oxygen and carbon dioxide levels in the blood, as well as the pH. (Example: "Nothing's right with this guy. His blood gases stink.")

A measurement of the amount of oxygen, carbon dioxide and acid in the patient's blood. These measurements are needed to make adjustments in how much oxygen the patient should receive.

If blood is heated above a naked flame, evil-smelling vapours will issue from it. These are blood gases, and are the reason why blood should not be heated above a naked flame.