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Partial Oxygen Saturation During Exhaled Breath Collection (Fraction of Respiratory Gas)

Published: August 9, 2026Updated: August 16, 2026

This test measures the oxygen content in air you exhale, reflecting how well your lungs deliver oxygen to your blood.

Quick summary

["Helps assess lung function and oxygen exchange efficiency."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
76105-6
Short code
O2 during expir VFr/PPres Gas DS.EL
Synonyms
O2 during expir VFr/PPres Gas DS.EL
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What This Test Measures

The test captures a sample of the air you exhale, analyzing its oxygen concentration. This indirect measurement helps evaluate how effectively your lungs transfer oxygen into your bloodstream during breathing.

How It’s Performed

You’ll breathe into a special device that collects your exhaled breath over a short period. No needles or blood draws are involved. The device measures oxygen levels in the exhaled air.

Why It’s Done

Doctors may order this test to diagnose or monitor conditions affecting lung function, such as chronic obstructive pulmonary disease (COPD), asthma, or other respiratory issues.

Common Conditions Monitored

This test is often used to track lung health in chronic respiratory conditions, especially when assessing oxygen levels in exhaled breath for early detection or management of lung-related problems.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Frequently asked questions

How long does it take to get results from this test?
Results are typically available within a few hours to a day, depending on your lab’s processing time. Your healthcare provider will discuss the findings with you during your follow-up visit.
Can I prepare for this test in any way?
No special preparation is needed. You can eat, drink, or exercise normally before the test. Avoid smoking or using inhalers right before testing if instructed by your doctor.
Is there any risk or discomfort associated with this test?
There is no discomfort. The test involves exhaling into a device, which is quick and painless. If you have difficulty breathing or experience shortness of breath, inform your healthcare provider beforehand.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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