Perfusion Index (Perfusion Rate) via Multiplexed Exhaled Breath Analysis
This test measures how well different areas of your lungs are receiving blood flow, using exhaled breath samples. It may help assess lung function or circulation in specific regions.
["This test evaluates lung perfusion efficiency through breath analysis—useful for detecting uneven blood flow in the lungs."]
Key facts at a glance
- LOINC
- 81568-8
- Short code
- PT.perfusion Hrt W mult exer
- Synonyms
- PT.perfusion Hrt W mult exer
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- pt-perfusion
- CPT
- 85610
- SNOMED
- 396252006
- 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 perfusion index evaluates how effectively your lungs receive blood flow, broken down by region. This is done by analyzing chemical markers in exhaled breath, which reflect blood flow dynamics in the lungs. This method is often used in specialized settings to detect abnormalities in perfusion without invasive procedures.
Why It Might Be Ordered
Your healthcare provider may order this test if you have symptoms like shortness of breath, suspected lung conditions (e.g., pulmonary embolism, chronic obstructive pulmonary disease), or if monitoring lung function is needed during certain treatments. It can also help assess perfusion in patients with known vascular or lung diseases.
Sample Collection and Preparation
You’ll exhale into a specialized device that collects and analyzes your breath over a set period. No fasting or special preparation is required, but follow your provider’s instructions for timing. The test is typically quick and painless, with no needles or blood draws involved.
What to Expect During the Test
You’ll sit comfortably while exhaling into a mouthpiece connected to a machine. The device measures breath composition in real time, often taking just a few minutes. You may be asked to breathe deeply or hold your breath briefly to ensure accurate results.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Abnormal perfusion indices may indicate conditions like pulmonary embolism (blocked blood flow in the lungs), lung diseases (e.g., fibrosis), or vascular issues affecting lung circulation. Low perfusion in certain areas could signal reduced blood flow, which may require further investigation or treatment adjustments. This test is particularly useful for monitoring patients with known perfusion disorders or during diagnostic evaluations.
Short name
Perfusion Index (Exhaled Breath)
Frequently asked questions
How long does it take to get results?
Is this test painful or uncomfortable?
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