Test Overview
Test Methodology

Abbott I-Stat - ion selective potentiometry (pH, PCO2), amperometrically (pO2, lactate), calculation (HCO3)

Test Usage

Performed at authorized locations by point of care operators. pH, PO2, PCO2 measurements are used in the diagnosis monitoring, and treatment of respiratory disturbances and metabolic and respiratory-based acid-base disturbances. Lactate measurements are used in (1) the diagnosis and treatment of lactic acidosis in conjunction with measurement of blood acid/base status, (2) monitoring tissue hypoxia and strenuous physical exertion, and (3) diagnosis of hyperlactatemia.

Reference Range *

Reference ranges are available in the iStat CG4+ Blood Gas and Lactate test procedure located on the POC website: https://www.pathology.med.umich.edu/point-of-care

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Limitations

•Prolonged tourniquet application and forearm exercise may decrease pH due to localized production of lactic acid.
•Exposure of sample to air will cause an increase in pH , a decrease in pCO2 and increase in pO2.
•Results may be affected in the following situations: hemolysis, traumatic draw, pumping fist during draw, extended delay between drawing and testing thee specimen.

Test Details
Analytic Time

2 minutes

Soft Order Code
MiChart Code
POC Survival Flight Blood gas w/ Lactic
Point of Care
Point of Care
Specimen Requirements
Collection Instructions

Collect in lithium heparin syringe/tube.

Special Handling

Samples must be tested within 30 minutes of collection and immediately after exposing the sample to room air.

Normal Volume
3 mL whole blood
Minimum Volume
95 µL whole blood
Rejection Criteria
•Clotted samples.
•Samples in anticoagulant tubes other than lithium or sodium heparin.
•Air bubbles in sample.
•Specimens older than 30 minutes
Additional Information

For more test specific information, please refer to the test procedure found on the Michigan Medicine POC website: https://www.pathology.med.umich.edu/point-of-care

CPT Code
pH, pCO2, pO2, HCO3 (82803) lactic (83605)
pH (2746-6), pCO2 (2021-4),pO2 (2705-2), HCO3 (14627-4), lactic (2519-7)