Blood gas is a laboratory test of blood where the purpose is primarily to measure ventilation and oxygenation. The source is generally noted by an added word to the beginning; arterial blood gases come from arteries, venous blood gases come from veins and capillary blood gases come from capillaries.
- pH — The acidity or basicity of the blood.
- PaCO2 — The partial pressure of carbon dioxide in the blood.
- PaO2 — The partial pressure of oxygen in the blood.
- HCO3 — The level of bicarbonate in the blood.
- BE — The base-excess of bicarbonate in the blood.
Purposes for testing
- Diabetic ketoacidosis
- Lactic acidosis
- Metabolic acidosis
- Respiratory acidosis
- Respiratory alkalosis
Abnormal results may be due to a wide range of diseases, including poisoning and trauma as well as lung, kidney, or metabolic diseases. Head or neck injuries or other injuries that affect breathing can also lead to abnormal results.
- Seifter JL. Acid-base disorders. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 119
Blood Gas Interpretation - Simplified process for blood gas interpretation.