Bicarbonate (CO2) |
EPIC Test Name
CO2 LEVEL, TOTALEPIC Code
LAB55Specimen Requirements
plasma | |
---|---|
Minimum Volume: | 0.5 mL |
Collection: | Collect specimens using standard laboratory procedures. |
Transport: | Room Temperature ASAP |
Stability: | Room Temperature: 40 hours at 15-25 degrees C Refrigerated: 7 days at 2-8 degrees C (tightly capped) Frozen: 6 months at -20 to -80 degrees C |
Container: | LT GRN |
Rejection Causes: | Hemolysis, Insufficient Sample Volume |
Methods
Spectrophotometric assay using phosphoenolpyruvate in the presence of PEPCTurnaround Time
Specimen | Turnaround Time | Frequency |
---|---|---|
plasma | Stat: 90 minutes Routine: 4 hours | 24/7 |
Reference Ranges
Spectrophotometric assay using phosphoenolpyruvate in the presence of PEPC
Age | All Range | Unit | Critical Values |
---|---|---|---|
0 days up to 29 days | 22-29 mmol/L | mmol/L | <15 and >35 mmol/L |
29 days up to 999 days | 22-29 mmol/L | <10 and >40 mmol/L |
Clinical Indications
Bicarbonate is the second largest fraction of the anions in plasma after CL-. It includes bicarbonate (HCO3-) and carbonate (CO32-) ions, as well as the carbamino compounds. At the physiological pH, the concentration of carbonate is 1/1000 that of bicarbonate. The carbamino compounds exist in such low quantities that they are generally not mentioned specifically.The bicarbonate content of serum/plasma is used as an indicator of electrolyte dispersion and anion deficit. Together with pH, bicarbonate concentrations are used in the diagnosis and treatment of numerous potentially serious disorders associated with acid‑base imbalance in the respiratory and metabolic systems. Some of these conditions are diarrhea, renal tubular acidosis, renal failure, carbonic anhydrase inhibitors, hyperkalemic acidosis, and diabetic ketoacidosis.
Additional Information
Determination of bicarbonate (HCO3) actually includes dissolved carbon dioxide (CO2). CO2 can diffuse from the sample into the air due high partial pressure once the vacutainer tube is opened. This may change in the measured bicarbonate concentration in the sample by a rate of about 6 mmol/L per hour. The sample tube opening time should be kept minimal as possible.Common Synonyms
TCO2Performed
Lab |
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Chemistry - Community |
Chemistry - Downtown |
Verona Cancer Center |
Interpretative Information
Values of bicarbonate (HCO3) and carbon dioxide (CO2) above or below reference ranges indicate an acid-base imbalance. However, the nature of the acid-base imbalance cannot be determined based on the bicarbonate value alone. Its value has significance in the context of other electrolytes, such as pH and pCO2.CPT
82374LOINC
1963-8References
Shindler E, Brown SM, Scott M. Electrolytes and Blood Gases. In Tietz Textbook of Clinical Chemistry. Edited by N Rifai, AR Norwath and C Wittwer, 6 ed. St. Louis, Missouri, Elsevirer Inc, 2018, pp 604-625. ISBN: 978-0-323-35921-4Contact Information
Chemistry - Downtown: (315)464-4460Chemistry - Community: (315)492-5531
Verona Cancer Center: (315)473-3859