Arterial Blood Gas (ABG)

What is an ABG?

An ABG is a procedure in which blood is drawn from an artery for laboratory analysis. Because it comes from an artery, the blood is not drawn from the same place as other laboratory procedures. The most common site is on the inside of the wrist where you feel your pulse. The procedure only takes about five minutes but the results will not be available before you leave.

Why does my doctor want me to have an ABG?

The efficient transport of oxygen and carbon dioxide to and from your tissues is vital to your health. As you breathe, oxygen crosses a microscopic membrane in your lungs known as the alveolar-capillary membrane. Once across the membrane, oxygen attaches to hemoglobin in the blood and is delivered to organs and muscles to use for energy. The by-product of this cellular metabolism is called carbon dioxide. Carbon dioxide attaches to hemoglobin and is transported back to the lungs to be exhaled. If you have lung disease or other difficulties breathing, your physician may order an ABG to make sure you are transporting oxygen and carbon dioxide efficiently. The results of the ABG may indicate that oxygen and carbon dioxide is not diffusing across the alveolar-capillary membrane or that there is not enough hemoglobin in your blood.

What do I need to do before I come in for my test?

Make sure you have you physician's order. You cannot be admitted for the test without an order. Present your orders to the admission clerk and she will give you additional paperwork to bring to our department.