The bicarbonate test measures the amount of carbon dioxide in the body fluid such as serum. This test is also known as total co2 test or just as a co2 test. Most of the carbon dioxide in the body is found in the form of bicarbonates and hence has to be measured in the same form. This is also the reason why this test is called as bicarbonate test. It measures three types of carbon dioxides in the human body, bicarbonates, carbonic acid and dissolved carbon dioxide. This test is usually ordered together with a group of other tests such as tests for sodium, potassium and chloride. These tests together are called as electrolyte panel or chemistry screen.
The CO2 test is usually done when a person has breathing problems. It can be done for routine blood screen. It finds out the body’s acid and base balance. The bicarbonate test helps monitor a condition of electrolyte imbalance or even to monitor the treatment for the same. The doctor might order this test if he suspects that water retention or dehydration is causing electrolyte imbalance.
There is no preparation needed for this test. The heath care provider might ask you to stop the intake of certain prescription and non-prescription medicine. Medicines which increase the level of bicarbonates in the human body such as barbiturates, bicarbonates, loop diuretics, hydrocortisone and fludrocortisones should be stopped as they will interfere with the tests results. Also, drugs such as methicillin, tetracycline, triamterene, nitrofurantine and thiazide diuretics should be stopped as they lower the bicarbonate levels in the body.
For this test, blood is usually drawn from the lower arm. An elastic band is wrapped around the upper arm to apply pressure so that the veins swell and make it easy to draw blood through the needle. The site is first cleaned with an antiseptic. A needle is then inserted gently into the vein. The blood drawn is then stored in an airtight vial. The elastic band is then removed. The needle inserted site is then covered with cotton gauze or a cotton ball and covered with a bandage. This is done in order to apply pressure so that the bleeding stops. For infants or young children the blood sample is taken by puncturing the skin with a lancet. Once the blood is collected the site is covered with a bandage.