Oxygen saturation of hemoglobin in arterial blood (measured over 8 hours)
This test measures how well oxygen is bound to hemoglobin in your blood over an 8-hour period. It helps assess long-term oxygen delivery to tissues, often used in conditions affecting circulation or oxygen transport.
["This test evaluates sustained oxygen-carrying capacity in your blood, useful for monitoring chronic conditions."]
Key facts at a glance
- LOINC
- 19949-7
- Short code
- OxyHgb 8h Max % BldA
- Synonyms
- OxyHgb 8h Max % BldA
- Category
- hematology
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Ref low
- 12
- Ref high
- 17.5
- Critical range
- 7 N/A – 20 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85018
- SNOMED
- 900000000000003004
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your healthcare provider may order this test if you have symptoms like fatigue, dizziness, or shortness of breath that suggest poor oxygen use, or if you have conditions like chronic obstructive pulmonary disease (COPD), heart failure, or peripheral artery disease. It may also be part of a broader evaluation for suspected metabolic or blood-related disorders.
What Does the Test Involve?
A small blood sample is taken from a vein, usually in your arm. The blood is analyzed to measure oxygen saturation levels over time. This may involve multiple samples collected at intervals or processed in a specialized manner to track changes over 8 hours.
Sample Collection and Preparation
Blood is drawn into a tube that prevents clotting. The sample is then processed to separate arterial blood components, ensuring accurate measurement of oxygen saturation in red blood cells.
What Are Common Results?
Results are presented as a maximum oxygen saturation value over the 8-hour period. Interpretation depends on clinical context and may compare to expected ranges for healthy individuals or specific patient populations.
Reference range
Adult males: 13.5-17.5 g/dL; Females: 12.0-16.0 g/dLN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
OxyHb 8h Max
Frequently asked questions
What does an abnormal result mean?
How often is this test repeated?
Can I eat or drink before this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy