Carbon Dioxide Production Rate (Respiratory Metabolism)
This test measures how much carbon dioxide your body produces during respiration, often assessed in relation to oxygen consumption. It helps evaluate lung function and metabolic processes.
["This test helps doctors understand how well your lungs and metabolism are working together."]
Key facts at a glance
- LOINC
- 76266-6
- Short code
- CO2 production/IBW Respiratory
- Synonyms
- CO2 production/IBW Respiratory
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 22
- Ref high
- 28
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 82374
- 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 Does This Test Measure?
Carbon dioxide production is a byproduct of cellular respiration—the process where your body converts food into energy. This test specifically looks at the rate at which your body releases CO₂, which can reflect how efficiently your lungs extract oxygen and release waste gases.
Why Might You Need This Test?
Doctors may order this test to diagnose or monitor conditions affecting lung function, such as chronic obstructive pulmonary disease (COPD), sleep apnea, or metabolic disorders. It can also be used in research or specialized clinical settings to assess respiratory efficiency.
How Is This Test Performed?
This test typically involves wearing a mask connected to a machine that measures gas exchange over time. You may breathe normally or follow specific breathing patterns while the device records CO₂ production. The test may last minutes to hours, depending on the protocol.
What Does the Result Mean?
Results are usually expressed as a rate (e.g., milliliters of CO₂ produced per minute). Abnormal rates may indicate poor lung function, metabolic issues, or other underlying health concerns that need further evaluation.
Reference range
Adult: 22-28 mmol/LN/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
CO₂ Production Rate (Respiratory)
Frequently asked questions
What is the purpose of measuring CO₂ production in a respiratory test?
How long does a CO₂ production test usually take?
Can this test be done at home?
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