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Single breath counting correlates with pulmonary function test values.

Asthma is a chronic disease that affects significant percentage of children. The standard means to measure asthma severity is by spirometry. The forced expiratory volume in the first second obtained by spirometry is the best known parameter for asthma severity assessment. But spirometry may not be available in all emergency rooms to evaluate children presenting with exacerbation of asthma. In adult simple hand held peak expiratory flow meter can be used. But peak expiratory flow is effort dependent and many children may not perform it properly leading to unreliable results.

In a study published in American Journal of Emergency Medicine, researchers from Penn State Hershey Medical Center. Hershey, PA, USA suggest that single breath counting could be used as an alternative to the peak expiratory flow measurement. Single breath counting is how far an individual can count in normal speaking voice after a maximal inspiration. In the published study, single breath counting strongly correlated with the peak expiratory flow rate and forced expiratory volume in first second.. This suggests that single breath counting could be potentially used in children presenting to the emergency room with acute asthma exacerbation to assess the severity of airflow obstruction.

Reference
http://www.ajemjournal.com/article/S0735-6757(09)00375-1/abstract