Spirometry: FEF 25-75% may predict reversible airflow obstruction in children

This new study challenges the assumption that the assessment of forced expiratory flow between 25% and 75% of vital capacity (FEF(25-75)) does not provide additional information in asthmatic children with normal FEV(1) percent predicted.

Among 400 children with normal FEV(1), FEF 25-75%, and FEV(1)/FVC were correlated with:

- methacholine challenge
- peak expiratory flow
- fraction of exhaled nitric oxide (FeNO)
- bronchodilator responsiveness

FEF(25-75) at 65% of predicted value had a 90% sensitivity and a 67% specificity for detecting a 20% increase in FEV(1) after albuterol inhalation.

The study authors concluded that FEF 25-75% was well correlated with bronchodilator responsiveness in asthmatic children with normal FEV(1). FEF 25-75% might be of use in predicting the presence of reversible airflow obstruction.



What is spirometry? A simple breathing test (video). From The Lung Association YouTube channel: Dr. Roger Goldstein explains what spirometry is (a simple breathing test), who should get tested and what spirometry tells health-care professionals. Visit www.lung.ca for more information.

References:

Forced expiratory flow between 25% and 75% of vital capacity and FEV1/forced vital capacity ratio in relation to clinical and physiological parameters in asthmatic children with normal FEV1 values. J Allergy Clin Immunol. 2010 Sep;126(3):527-34.e1-8. Epub 2010 Jul 16.

Resurrection men and the FEF25-75. JACI, 2010.

Image source: Spirometry, from Wikipedia, the free encyclopedia, GNU Free Documentation License.

PFTs: Question everything http://bit.ly/1j7WYTz