An arterial blood gas (ABG) test is a blood test that measures the levels of oxygen and carbon dioxide in your child’s blood. It also measures the balance of acids and bases in the blood (called the pH).
This test measures how well the body uses oxygen and gets rid of carbon dioxide. Blood gas tests may be done when your child has an injury or illness that affects breathing, or if your child is having trouble breathing. It may be done to:
There is usually no special preparation for these tests. If your child is using oxygen therapy, be sure to tell the technician how much oxygen your child is on, for example, 2 liters per minute, and how many minutes or hours your child has been on oxygen before the test.
A small amount of blood is taken from an artery in your child’s arm with a needle. An artery is a vessel that carries oxygen-rich blood from the heart and lungs to the rest of the body. The artery most commonly used for this test is the artery in the wrist where your child’s pulse is usually checked. Medicine to numb to spot where the needle goes in may be used. For newborns, blood may be taken from the umbilical cord.
If your child is hospitalized and needs frequent testing, your child may have a small tube (catheter) put in his artery. The tube can stay there for several days. The blood needed for an arterial blood gas test can be taken from this tube without sticking your child’s artery with a needle each time.
The blood is tested in a lab right away to get the most accurate results.
Having this test will take just a few minutes.
Ask your healthcare provider when and how you will get the result of the test.
Many health problems can cause abnormal ABG results. Examples of possible causes of an abnormal result are:
Test results are only one part of a larger picture that takes into account your child’s medical history and current health. Sometimes a test needs to be repeated to check the first result. Talk to your child’s healthcare provider about what your child’s results mean.
If your child’s test results are not normal, ask your child’s healthcare provider: