Blood gases

Blood gases - A test for determining the acidity–alkalinity (pH) and the concentrations of oxygen, carbon dioxide, and bicarbonate in the blood. The test is carried out on a sample of blood taken from an artery, usually at the wrist or groin.

It is useful in diagnosing and monitoring respiratory failure. Bicarbonate and acidity reflect the acid–base balance of the body, which may be disturbed in conditions such as diabetic ketoacidosis, aspirin poisoning, hyperventilation, or repeated vomiting. Blood oxygen can also be measured without taking a blood sample by using an oximeter.