Bicarbonate Test measures the level of bicarbonate in the blood. The bicarbonate (or total CO2) test is almost never ordered by itself. It is usually ordered along with sodium, potassium, and chloride as part of an electrolyte panel. The electrolyte panel is used to detect, evaluate, and monitor electrolyte imbalances. It may be ordered as part of a routine exam or to help evaluate a chronic or acute illness. It may be ordered at intervals to help monitor conditions, such as kidney disease and hypertension, and to monitor the effectiveness of treatment for known imbalances.