The TCO2 blood test measures the total amount of carbon dioxide that is within the body. It is ordered to either discover, monitor, or treat many different serious diseases that have been associated with a change to the body’s acid-base balance. Most of the carbon dioxide [CO2] that is in the body comes in the form of HCO3, which is called bicarbonate. It would be fair to say that the TCO2 blood test is really a measurement of bicarbonate levels.
To get the blood for this blood test, a draw is usually obtained from a vein in the elbow or back of the hand. If a vein cannot be located or one is not viable in these locations, then other blood draw methods may be recommended by the laboratory technician.
You may need to alter the medications or supplements that are being taken before the blood draw. Your doctor will tell you which medications must be avoided for the blood test and how long this must happen. Do not change the medication that you are taking without speaking to your doctor.
Why Is the TCO2 Blood Test Ordered?
Most of the time, the TCO2 blood test is ordered as part of a complete metabolic panel. It may be ordered as part of a panel to measure electrolyte levels as well. When there are changes in bicarbonate levels within the body, it indicates that someone could be retaining too many fluids or not able to retain enough fluids. These changes cause the electrolyte levels to become imbalanced and a positive result on the TCO2 blood test will be obtained.
If there is a suspicion of lung or kidney functions being inadequate, then this blood test may be independently ordered to determine a diagnosis. This is because the kidneys are one of the primary organs that help to regulate bicarbonate levels within the body. It may also be independently ordered from a panel to determine if a treatment plan is being effective.
A normal test result is considered to be 23-29 milliequivalents per liter [mEq/L].
My Results Were Just Slightly Abnormal – What Should I Do?
Normal value ranges can vary from laboratory to laboratory. A couple of points in either direction of the range stated above are often considered to still be normal results. You will want to speak with your doctor or treatment team about what slightly abnormal results may mean for you.
If there are lower levels of bicarbonate than expected, then this may indicate a few specific issues may be present and need to be addressed. The most common reason for low levels of CO2 in the body is because of recent or persistent diarrhea. It may also indicate the presence of the following issues.
- Addison disease.
- Ketoacidosis.
- Kidney disease.
- Metabolic acidosis.
If your TCO2 blood test results are higher than normal, then the most common reason for this is because of recent vomiting. Certain breathing disorders may also cause results that are higher than the normal range. The most important item to rule out with high results is Cushing Syndrome, which means a person’s body is either making too much cortisol or that there is medication causing the production of too much cortisol.
There Are Certain Conditions That Change Bicarbonate Levels
People who are suffering from dementia or delirium, even in mild forms, may find that their bicarbonate levels are either high or low. The TCO2 blood test in these circumstances may be used as a first diagnostic effort to determine if there is something abnormal within the body. Additional tests may be ordered to follow-up on the high or low results.
This blood test is commonly ordered even when there are no health issues suspected. It is a tool that is used to confirm the presence of good health just as it can be used as a tool to determine if there is a health situation present that needs to be addressed. Most people will have a normal result from their TCO2 blood test.
If an abnormal test result is received, it may still be medically insignificant. Do not ignore an abnormal test result, even if you are experiencing no symptoms. Speak with your doctor about what the results of your TCO2 blood test mean and that will allow you to be able to begin a treatment regimen that will resolve the issue and bring your body back into the balance that it desires.