Carbon dioxide (co2) test

This test measures the level of bicarbonate in your child's blood. Bicarbonate is a form of carbon dioxide (CO2). CO2 is a waste product of metabolism. The blood carries it to the lungs, where it is exhaled. Bicarbonate keeps your child's blood at the right pH level (not too acidic, and not too basic).

The test is also called a carbon dioxide test or a bicarbonate test.

CO2 testing is often done as part of a group of blood tests (chemistry screen) to help find the cause of many kinds of symptoms. These causes may include many kidney diseases, some lung diseases, and metabolic problems.

• A health professional uses a needle to take a blood sample, usually from the arm.

• In general, there's nothing you have to do before this test, unless your doctor tells you to.
• Tell your doctor ALL the medicines, vitamins, supplements, and herbal remedies you take. Some may affect the results of the test. Your doctor will tell you if you should stop taking any of them before the test and how soon to do it.

Each lab has a different range for what's normal. Your lab report should show the range that your lab uses for each test. The normal range is just a guide. Your doctor will also look at your results based on your age, health, and other factors. A value that isn't in the normal range may still be normal for you.

Results are usually ready in 1 to 2 days.

High values

A high level may be caused by:

• Vomiting.
• Dehydration.
• Blood transfusions.
• Overuse of medicines that contain bicarbonate (especially antacids).
• Conditions such as anorexia, chronic obstructive pulmonary disease (COPD), fluid in the lungs (pulmonary edema), heart disease, Cushing's disease, or Conn's syndrome.

Low values

A low level may be caused by:

• Hyperventilation.
• Aspirin or alcohol overdose.
• Diarrhea, dehydration, or severe malnutrition.
• Liver or kidney disease.
• A massive heart attack.
• Hyperthyroidism or uncontrolled diabetes.
• A serious infection of the whole body (sepsis).