What the American Thoracic Society (ATS) spirometry performance standards?

Updated: May 14, 2020
  • Author: Kevin McCarthy, RPFT; Chief Editor: Nader Kamangar, MD, FACP, FCCP, FCCM  more...
  • Print


The ATS has published guidelines for a standardized technique that includes spirometer performance standards. A reasonable end-point for the maneuver in the absence of true flow cessation (ie, airway obstruction is present) is 15 seconds. Patients often discontinue the forced exhalation prematurely because of the discomfort of prolonged forced exhalation. A modified technique in which the patient exhales with maximum force for four seconds followed by continued relaxed exhalation has been shown to enhance the patient's ability to sustain expiration, thereby yielding a larger FVC in patients with airflow obstruction. It should be noted that, strictly speaking, the FVC obtained from using this technique is not a true FVC because maximum expiratory effort was not sustained during the entire exhalation.

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!