Also known as: Arterial blood gases; ABGs; pH; PO2; PCO2; Bicarbonate; HCO3-; Oxygen saturation
Formal name: Blood Gases
Related tests: Electrolytes; Bicarbonate, BUN, Creatinine
To determine if your lungs are functioning well enough to exchange oxygen and carbon dioxide if you are having symptoms of a respiratory problem; to determine if you have an imbalance in the amount of oxygen gas (O2) or carbon dioxide gas (CO2) in your blood or an acid-base imbalance, which may indicate a respiratory, metabolic, or kidney disorder
When you have difficulty breathing, shortness of breath, or rapid breathing; when you have symptoms of an oxygen/carbon dioxide imbalance or an acid-base imbalance; periodically when you have a condition that causes an acute or chronic oxygen shortage and you are on oxygen therapy; during certain surgeries to monitor your blood's oxygen and carbon dioxide levels
Most often a blood sample collected from an artery, usually the radial artery in the wrist,; sometimes a blood sample drawn from a vein in the arm; capillary blood from a heelstick may be used for babies
Typically none. However, if you are on oxygen therapy, the O2 may either be turned off for 20 to 30 minutes before the collection for a "Room Air" test or, if this cannot be tolerated or if the doctor wants to check your oxygen levels with the O2 on, the amount of oxygen being taken will be recorded.