What it means
The body's main buffer against acid, written HCO3. The kidneys keep or remove bicarbonate to hold the blood's pH steady, while the lungs control carbon dioxide. A low level points to metabolic acidosis (as in diabetic ketoacidosisdy-uh-BET-ik kee-toh-as-ih-DOH-sisA state of high blood glucose, ketones in the blood and acidic blood, caused by a lack of insulin.ket/o ketonesacid/o acid-osis abnormal conditionFull entry or severe diarrhea); a high level to metabolic alkalosis (as with vomiting or nasogastric suction). On a chemistry panel it is often reported as CO2 or total CO2.
For the nurse
Read the bicarbonate with the pH and PaCO2 on a blood gas to find the kind of acid-base problem. Report a falling value in a client with diabetes, kidney failure or severe diarrhea.
At a glance
| Normal range | Arterial blood gas: 22–26 mEq/L [22–26 mmol/L]. Serum CO2 on a metabolic panel runs slightly higher, about 23–29 mEq/L [23–29 mmol/L]; each lab sets its own range. |
|---|---|
| Abbreviations | HCO3 |
| Spanish | bicarbonato |
| Also written | HCO3, HCO3-, HCO₃, serum bicarbonate, total CO2, CO2 content, bicarbonate level, bicarbonate levels |
Related terms
electrolyte
A mineral that carries an electric charge when dissolved in body fluids, such as sodium, potassium, calcium and chloride.
diabetic ketoacidosis
A state of high blood glucose, ketones in the blood and acidic blood, caused by a lack of insulin.
arterial blood gas
A blood test from an artery that measures oxygen, carbon dioxide, bicarbonate and the blood's pH.
hypercapnia
Too much carbon dioxide in the blood, a PaCO2 above 45 mm Hg.