The blood test Bicarbonate HC03 determines the total amount of carbon dioxide(CO2) in the blood (separate serum tube) in all its different forms(CO2,H2CO3,HCO3-).
CO2 is produced during metabolism and transported with the exhaled air via the lungs.CO2 is part of the electrolytes in the body and is needed to balance the ratio of acid and base in the blood.
Carbon dioxide in the form ofHCO3-(bicarbonate) is the main form ofCO2 in the body. The negatively charged electrolyte can be excreted or retained in the kidneys to maintain the acid-alkaline balance.
Also,HCO3-along with sodium, potassium and chloride is important for electroneutrality at the cellular level.
TotalCO2 is usually requested as part of the electrolyte panel (sodium, potassium, chloride). When an acid-base imbalance is detected,CO2 analysis, together with other electrolyte determinations, can give an idea of the severity of the problem and its cause. This may be a respiratory deficiency, where the lungs are unable to exhale the correct amount ofCO2, or a metabolic deficiency, where the kidneys are unable to excrete the correct amount of bicarbonate.
A too high or too lowCO2 level means that the body has difficulty maintaining the acid-base balance (too highCO2: more than 30 mmol/L; too lowCO2: less than 20 mmol/L).
This test is hardly ever requested because it is very sensitive and can therefore fail quickly or give a deviating value due to interference factors. If it fails, you will receive the cost of the test back.
For bicarbonate it is necessary, if there are more parameters, to deliver a separate serum tube, because otherwise, when opening the tube for other analyses, a decrease already occurs by volatilization.