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 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.