Test Catalog

Test Id : HCO3

Bicarbonate, Serum

Useful For
Suggests clinical disorders or settings where the test may be helpful

Diagnosis and treatment of acid-base imbalance in respiratory and metabolic systems

Method Name
A short description of the method used to perform the test

Photometric/Enzymatic

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Bicarbonate, S

Aliases
Lists additional common names for a test, as an aid in searching

Carbon Dioxide, Plasma or Serum

CO2 (Carbon Dioxide) Plasma or Serum

Specimen Type
Describes the specimen type validated for testing

Serum

Necessary Information

Patient's age and sex are required.

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Specimen Volume: 0.5 mL

Collection Instructions:

1. Serum gel tubes should be centrifuged within 2 hours of collection.

2. Red-top tubes should be centrifuged and aliquoted within 2 hours of collection.

Forms

If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

0.25 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject
Gross lipemia OK

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 24 hours

Useful For
Suggests clinical disorders or settings where the test may be helpful

Diagnosis and treatment of acid-base imbalance in respiratory and metabolic systems

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Bicarbonate is the second largest fraction of the anions in plasma. Included in this fraction are the bicarbonate (HCO3[-]) and carbonate (CO3[-2]) ions, carbon dioxide in physical solution, as well as the carbamino compounds. At the physiological pH of blood, the concentration of carbonate is 1/1000 that of bicarbonate. The carbamino compounds are also present in such low quantities that they are generally not mentioned specifically.

 

The bicarbonate content of serum or plasma is a significant indicator of electrolyte dispersion and anion deficit. Together with pH determination, bicarbonate measurements 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, carbonic anhydrase inhibitors, hyperkalemic acidosis, renal failure, and ketoacidosis.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Males

12-24 months: 17-25 mmol/L

3 years: 18-26 mmol/L

4-5 years: 19-27 mmol/L

6-7 years: 20-28 mmol/L

8-17 years: 21-29 mmol/L

> or =18 years: 22-29 mmol/L

Females

1-3 years: 18-25 mmol/L

4-5 years: 19-26 mmol/L

6-7 years: 20-27 mmol/L

8-9 years: 21-28 mmol/L

> or =10 years: 22-29 mmol/L

 

Reference values have not been established for patients that are <12 months of age.

Interpretation
Provides information to assist in interpretation of the test results

Alterations of bicarbonate (HCO3) and carbon dioxide (CO2) dissolved in plasma are characteristic of acid-base imbalance. The nature of the imbalance cannot, however, be inferred from the bicarbonate value itself, and the determination of bicarbonate is rarely ordered alone. Its value has significance in the context of other electrolytes determined with it and in screening for electrolyte imbalance.

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Because the determination of bicarbonate (HCO3) actually includes dissolved carbon dioxide (CO2), this fraction will escape from the specimen into the air once the stopper is removed from the vacutainer tube. The rate of change in the bicarbonate determination is approximately 6 mmol/L in the course of 1 hour. If the logistics in the lab are different for processing high-volume routine specimens from STAT specimens, the extent of the error is bicarbonate determinations will be different. This is due to the length of time between removal of the stopper and sampling of the specimen for analysis. Fortunately, the errors in either case are relatively small and of little concern clinically.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

Tietz Textbook of Clinical Chemistry, Edited by Burtis and Ashwood. Philadelphia, PA, WB Saunders Company, 1994.

Method Description
Describes how the test is performed and provides a method-specific reference

This is a photometric rate reaction. Bicarbonate (HCO3[-]) reacts with phosphoenolpyruvate (PEP) in the presence of phosphoenolpyruvate carboxylase (PEPC) to produce oxaloacetate and phosphate. The oxaloacetate produced is coupled with NADH in the presence of malate dehydrogenase (MDH) to produce malate and NAD. The consumption of NADH causes a decrease in absorbance and is monitored in the UV range of 320 nm to 400 nm. The rate of change is directly proportional to the concentration of bicarbonate.(Package insert: Roche Bicarbonate reagent, Indianapolis, IN, July 2000)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Sunday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

Same day/1 to 2 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

1 week

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

82374

LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
HCO3 Bicarbonate, S 1963-8
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
HCO3 Bicarbonate, S 1963-8

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports