CO2 blood test

What is the CO2 Blood Test?

A carbon dioxide blood test measures the amount of carbon dioxide in the bloodstream. Carbon dioxide is an important product of the body’s metabolism and is an essential component of a healthy body’s chemistry. The test is also known as a CO2 blood test, or a bicarbonate test. It’s most commonly ordered along with an electrolyte panel, which can determine the levels of other substances such as sodium and potassium.

Preparation for the Test

The preparation for the CO2 blood test is minimal. You don’t need to fast or prepare in any special way. Just let the health care provider know if you’re taking any medications that might interfere with the test results.

Procedure for the Test

The CO2 blood test is performed in a health care provider’s office or lab. You'll be asked to lie down, and then the health care provider will use a needle to collect a sample of your blood. Then, the sample will be sent to a lab for testing. The procedure generally takes a few minutes and can be done on an outpatient basis.

Types of CO2 Blood Tests

  • Gastric Analysis: This test measures how much carbon dioxide the patient’s stomach contains. It’s used to diagnose stomach disorders such as ulcers and acid reflux.
  • Total CO2: This test measures the total amount of carbon dioxide in the bloodstream and is used to diagnose acid-base imbalances.
  • Arterial Blood Gas (ABG): This test measures the amount of carbon dioxide in an artery, which is a larger vessel than those used for venous blood testing. It’s used to diagnose respiratory disorders or heart failure.

Risks of the Test

The CO2 blood test carries no risks, aside from minor bruising from the needle prick. You may experience some discomfort with the needle prick but it should not be overly painful.

Why Is the Test Used?

The CO2 blood test is typically used to diagnose acid-base imbalances such as metabolic acidosis or alkalosis. It’s also used to diagnose other disorders such as kidney disease, certain types of infections, and respiratory disorders like COPD.

When Is the Test Ordered?

A CO2 blood test is usually ordered when a health care provider suspects an acid-base imbalance in the body. It may also be ordered as part of an overall checkup or when a patient is experiencing symptoms such as dizziness, fatigue, confusion, or rapid breathing.