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    Arterial Blood Gases

    Arterial Blood Gases



    Results

    An arterial blood gas (ABG) test measures the acidity (Reference pH Opens New Window) and levels of oxygen and carbon dioxide in the blood.

    Normal

    The normal values listed here—called a reference range—are just a guide. These ranges vary from lab to lab and depend upon the elevation above sea level. Your lab may have a different range for what's normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.

    Results are usually available right away.

    Arterial blood gases (at sea level and breathing room air) Reference 1
    Partial pressure of oxygen (PaO2):

    Greater than 80 Reference mm Hg Opens New Window (greater than 10.6 kPa)
    Partial pressure of carbon dioxide (PaCO2):

    35–45 mm Hg (4.6–5.9 kPa)
    pH:

    7.35–7.45
    Bicarbonate (HCO3):

    22–26 Reference mEq/L Opens New Window (22–26 Reference mmol/L Opens New Window)
    Oxygen content (O2CT):

    15–22 Reference mL Opens New Window per 100 mL of blood (6.6–9.7 mmol/L)
    Oxygen saturation (O2Sat):

    95%–100% (0.95–1.00)

    The concentration of oxygen being breathed, called the fraction of inhaled oxygen (FiO2), is also usually reported. This is only useful if you are receiving oxygen therapy from a tank or are on a ventilator.

    Many conditions can change blood gas levels. Your doctor will talk with you about any abnormal results that may be related to your symptoms and past health.




    By: Reference Healthwise Staff Last Revised: Reference May 30, 2012
    Medical Review: Reference E. Gregory Thompson, MD - Internal Medicine
    Reference Robert L. Cowie, MB, FCP(SA), MD, MSc, MFOM - Pulmonology


    This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Reference Terms of Use. Reference How this information was developed to help you make better health decisions.


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