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Test Code LABGAS5LRFLX Arterial Blood Gas Plus Serial Lactate

Clinical Information

This order includes an initial lactate measurement that will reflex to a second lactate test 2 hours later if the initial lactate is 2 mmol/L or greater.

Synonym

  • GAS5L
  • 2HRLACT

Profile Information

Reporting Name Available Separately Always Reported
pH No Yes
pCO2 No Yes
pO2 No Yes
HCO3 No Yes
sO2 No Yes
Base Excess No Yes
FIO2 No Yes
Lactate, Whole Blood Yes Yes

Specimen Required

Preferred Container/Tube: Dry Lithium Heparin Syringe
Acceptable Container/Tube: Dry Lithium Heparin Syringe
Specimen Volume: Full syringe
Specimen Minimum Volume: Full syringe

Specimen Stability Information

Ambient: 30 minutes
Refrigerated: 30 minutes

Rejected Due To

  • Unacceptable container type
  • Quantity not sufficient
  • Clotted specimens
  • Received >30 minutes from collection time

Testing Algorithm

If the initial lactate measurement is ≥ 2.0 mmol/L, Lactate, 2 Hour Draw (LABLAC2HR) will be performed at an additional charge.

Reflex Tests

Reporting Name Available Separately Always Reported
Lactate, 2 Hour Draw No No

Reference Values

pH
0-29 days: 7.29-7.45
30+ days: 7.35-7.45

 

pCO2
0-29 days: 27-40 mm Hg
30+ days: 32-48 mm Hg

 

pO2
83-108 mm Hg

 

HCO3
0-29 days: 17-24 mmol/L
30+ days: 22-28 mmol/L

 

sO2
0-365 days: 40-90 %
1+ years: 94-98 %

 

Base Excess
-3.0-3.0 mmol/L

 

Lactate, Whole Blood
0.5-1.6 mmol/L

Cautions

Contamination of samples with ambient air will drive the pO2 to equilibrate with ambient air (150 mmHg) leading to falsely low or falsely elevated results depending on the initial pO2 level; as well as falsely decrease the pCO2; and falsely increase the pH, which will also affect the portion of calcium bound to protein. Therefore, care should be taken to expel all air bubbles from all blood gas samples.

Syringes that are not completely filled will have increased heparin concentrations that can lead to erroneous measurements of pO2, pCO2, sodium, potassium, and ionized calcium.

Method Description

pO2, Lactate: Amperometry

pH, pCO2: Potentiometry

Base excess GEM: HCO3- - 24.8 + 16.2 x (pH - 7.4)

HCO3 GEM: Log (HCO₃ (c)) =   pH + log(pCO₂) – 7.608 mmol/L

sO2: Co-oximetry; sO2 = 100 x O2Hb%/(O2Hb% + HHb%)

Performing Lab

Clinical Lab UH
Clinical Lab West Campus
Respiratory Therapy East
Respiratory Therapy UH

Day(s) Performed

Monday through Sunday

Reporting Name

Arterial Blood Gas + Lactate

CPT Code Information

82803
83605
83605 (if appropriate)

LOINC Code Information

11558-4
11557-6
11556-8
1959-6
2713-6
11555-0
3150-0
32693-4
32693-4 (if appropriate)