Bicarbonate
Also known as: Total CO2; TCO2; Bicarb
Formal name: Bicarbonate
The Test Sample
What is being tested?
The total CO2 test measures the total amount of carbon dioxide in the blood, mostly in the form of bicarbonate (HCO3-); in many laboratories, bicarbonate is now measured directly. Bicarbonate is a negatively charged electrolyte that is excreted and reabsorbed by the kidneys. It is used by the body to help maintain the body’s acid-base balance (pH) and secondarily to work with sodium, potassium, and chloride to maintain electrical neutrality at the cellular level.
Measuring bicarbonate (or total CO2) as part of an electrolyte or metabolic panel may help diagnose an electrolyte imbalance, acidosis or alkalosis as the result of a disease process or condition.
How is the sample collected for testing?
A blood sample is drawn by needle from a vein in the arm.
NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.
Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.
