Lab Information Manual

Laboratory:

Clinical Biochemistry (POC (Point of Care) TEST)

Test Name:

Total CO2 - epoc - (B)

Test Code: COVB, COAB

Clinical Information:

Alternate Name(s): Carbon Dioxide, Total

Description: Total CO₂ (TCO2) measurements are often used as a estimate of bicarbonate. TCO2 is the sum of all forms of CO2 present in the blood, of which approximately 95% exists as bicarbonate.

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. An elevated anion gap strongly suggests the presence of metabolic acidosis [Anion gap = Na - (Cl + TCO₂)].

The whole blood anion gap may be requested from the epoc test menu.

Collection Devices:

Preferred Device:	1 - Li Heparin, NO GEL 4.0 mL Tube(s) - Full Tube Collection Li Heparin, NO GEL 4.0 mL Tube(s) - Full Tube Collection Manufacturer: BD (Becton Dickinson) Catalogue #: 367884
Alternate Device:	1 - Balanced Heparin Blood Gas Syringe (AT LEAST HALF FULL) No Image Available Balanced Heparin Blood Gas Syringe (AT LEAST HALF FULL) Manufacturer: Catalogue #:

Capillary specimens must be collected in a balanced heparin capillary tube (FULL collection), capped, mixed, and tested within 5 minutes of collection.

Specimen Required:

Whole Blood: 4.0 mL

Pediatric Whole Blood: 0.1 mL

Collection Information: Evacuated blood tubes must be FULL to maintain specimen stability. Specimens must remain capped until tested to avoid contamination with air.

Rejection criteria: clots, underfilled tube, leaking specimens, and specimens not received within 30 minutes of collection.

Capillary samples must be tested at the bedside, within 5 minutes.

Specimen Stability:

Ambient: 30 minutes (Vacutainer, syringe); 5 minutes (capillary)

Refrigerated: DO NOT REFRIGERATE

Frozen: DO NOT FREEZE

Do not submit specimens on ice.

Referral:

Only available at sites which perform epoc testing on-site.

Requisition:

_SH Hospital Biochemistry Hematology Non Winnipeg Brandon (R250-10-91)

Reference Values:

Reference Intervals: 23 – 30 mmol/L

Critical Values: <10.0 mmol/L

>40 mmol/L

Method of Analysis: Modified Henderson-Hasselbalch determination using pH and pCO₂

Siemens epoc® Blood Analysis System, BGEM test card

Availability:

Daily or Stat