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    Light's Criteria for Exudative Effusions

    Provides Light's Criteria to help determine if pleural fluid is exudative.
    When to Use
    Why Use

    Light’s criteria can be used to determine the type of a patient’s pleural effusion and thus its etiology.

    The following diseases typically are exudative effusions, but in certain cases may be transudative:

    • Amyloidosis
    • Chylothorax
    • Constrictive pericarditis
    • Malignancy
    • Pulmonary embolism
    • Sarcoidosis
    • Trapped lung

    Light’s criteria are more sensitive than specific for exudative effusions.

    Calculation of Light’s criteria provides a systematic, validated approach to evaluating pleural fluid studies. It can save the clinician significant time and avoid unnecessary additional workup. Remember, however, that Light’s criteria is more sensitive than specific test for exudative effusions.

    Protein Parameters
    LDH Parameters
    Confirmed positive
    Confirmed negative


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    Creator Insights
    Dr. Richard W. Light

    About the Creator

    Richard W. Light, MD, is a professor in the Division of Allergy, Pulmonary, and Critical Care Medicine at Vanderbilt University School of Medicine. He was formerly chief of the pulmonary diseases section and associate chief of staff at the VA Hospital in Long Beach. Dr. Light is best known for his research on pleural disease for which he has published numerous papers and written in several textbooks.

    To view Dr. Richard W. Light's publications, visit PubMed

    Are you Dr. Richard W. Light? Send us a message to review your photo and bio, and find out how to submit Creator Insights!
    MDCalc loves calculator creators – researchers who, through intelligent and often complex methods, discover tools that describe scientific facts that can then be applied in practice. These are real scientific discoveries about the nature of the human body, which can be invaluable to physicians taking care of patients.
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