Sign in →

Browse by Name

  1. A
  2. B
  3. C
  4. D
  5. E
  6. F
  7. G
  8. H
  9. I
  10. J
  11. K
  12. L
  13. M
  14. N
  15. O
  16. P
  17. Q
  18. R
  19. S
  20. T
  21. U
  22. V
  23. W
  24. X
  25. Y
  26. Z
  27. #
 

Mayo Clinic Laboratories

Test Code RTBGAS Blood Gas, Arterial

Specimen and Container/Tube

Specimen Type: Whole blood 

Preferred Specimen: Syringe arterial 

Other Acceptable Specimens: None

Specimen Stability

Storage Temperature

Stability

Room temperature

30 minutes

Refrigerated

not acceptable

Frozen

not acceptable

Collection Instructions

  • Collect specimen per standard laboratory collection procedures. 
  • Remove all air from syringe. 
  • Remove needle. 
  • Cap tightly and mix well. 

Specimen Handling and Transport Instructions

UCMC Onsite Instructions: 

  • Collect specimen per standard collection procedure and send to laboratory immediately. 
  • Testing must be performed within 30 minutes of collection 

UCMC Offsite and UC MedLab Outreach Instructions: 

  • Specimens are not acceptable from offsite locations for blood gas testing 

Rejection Criteria

  • Common specimen rejected situations include: incorrect specimen type, insufficient volume, missing or incomplete specimen identifiers, incorrect specimen transport, or specimens outside stability limits. 
  • Specimens with needles attached will be rejected. 
  • Specimens with air bubbles. 

Reference Values

Analyte

Age

Sex

Normal Range

pH

All

All

7.33 – 7.45

pCO2, arterial

All

All

34 – 46 mmHg

pO2, arterial

All

All

80 – 100 mmHg

HCO3, arterial

All

All

22 – 29 mmol/L

Base excess, arterial

All

All

-3.0 – 3.0 mmol/L

SO2, arterial

All

All

60 – 80%

SAO2, arterial

All

All

94 – 98%

Hemoglobin, arterial

All

All

12.0 – 18.0 g/dL

Oxyhemoglobin, arterial

All

All

90 – 97%

Deoxyhemoglobin, arterial

All

All

2 – 6%

Carboxyhemoglobin, arterial

All

All

≤3.0%

Methemoglobin, arterial

All

All

≤2.0%

 

 

 

 

Critical Values

Analyte

Age

Low

High

pH, arterial

All

<7.20

>7.60

pCO2, arterial

All

<20 mmHg

>80 mmHg

>70 mmHg when pH <7.30

pO2, arterial

All

<40 mmHg

NA

Hemoglobin, arterial

All

<6.0 g/dL

NA

Carboxyhemoglobin

All

NA

>20.0%

Methemoglobin

All

NA

>10.0%

Turnaround Time

Turnaround times are relative to the time the specimen is received in the test laboratory. 

 

STAT Turnaround Time: 1 hour

Routine Turnaround Time: 4 hours

Testing Schedule: 24/7

Clinical Indications

Acid base disorder 

Test Components

pH, PCO2, PO2, HCO3-, Base Excess, SO2, SAO2, Hemoglobin, Oxyhemoglobin, Deoxyhemoglobin, Carboxyhemoglobin, Methemoglobin

Methodology

Potentiometry: pH, pCO2

Amperometry: pO2

Derived: HCO3-, base excess

Optical (CO-oximetry): SO2, hemoglobin, oxyhemoglobin, deoxyhemoglobin, carboxyhemoglobin, methemoglobin

CPT Codes

82805, 83050

LOINC Codes

2746-6, 2021-4, 2705-2, 39486-6, 40619-9, 19258-3, 14627-4, 1927-3, 2711-0, 718-7

Additional Information

  • For SO2: Measured oxygen saturation of functional hemoglobin according to the following formula. OxyHb/(OxyHb + DeoxyHb).
  • For OxyHb: Measured oxygen saturation of total hemoglobin according to the following formula. OxyHb/(OxyHb + DeoxyHb + COHb + MetHb).

Last Review Date

4/22/2025

Volume

Preferred Volume: 0.5 mL

Minimum Volume: 0.2 mL