Pulmonary function standards: a work in progress.

In this issue of RESPIRATORY CARE, a report by Borg and Thompson1 examines an aspect of the measurement of static lung volumes according to recommendations in the 2005 American Thoracic Society (ATS)/European Respiratory Society (ERS) Standardisation of Lung Function Testing.2-6 The procedure for measuring absolute lung volumes begins with establishing functional residual capacity, followed by excursions to minimum and maximum lung volume so that residual volume (RV) and total lung capacity (TLC) may be calculated. The standards recommend that, following the measurement of functional residual capacity, the preferred maneuver should consist of first exhaling to RV and subsequently inhaling to TLC. However, an alternate method of first inhaling to TLC and then exhaling to RV is permitted. Borg and Thompson1 studied the impact of using either the preferred or alternate method of measuring static lung volumes in a clinical setting in patients with normal lung function and patients with varying degrees of air-flow obstruction and restriction.