Airspace Dimension Assessment for early detection of lung function impairment in the peripheral airways of firefighters

INTRODUCTION: Firefighters have increased risk of chronic respiratory disease. Standard clinical techniques used in medical checkups may not detect the earliest microstructural changes in peripheral airways. A new technique called Airspace Dimension Assessment (AiDA) has been shown to enable early detection of emphysema in COPD. This method may be useful in the occupational setting to detect early pulmonary changes and enable prevention. The aim of the present study was to evaluate whether AiDA detects changes in the most peripheral airways of firefighters. METHODS: AiDA, measuring the effective airspace radius (r(AiDA)) and zero-second recovery (R(0)), was used as a complement to other standardised lung function measures in 21 male firefighters and 16 age-matched male controls. RESULTS: There were significant differences in r(AiDA) and R(0) between firefighters (mean±sd r(AiDA) 0.301±0.024 mm; mean±sd R(0) 0.336±0.116 arbitrary units) and controls (mean±sd r(AiDA) 0.276±0.044 mm; mean±sd R(0) 0.5760.168 arbitrary units), p=0.03 and p<0.001, respectively. Higher forced vital capacity was found in firefighters (mean 101% of predicted) than in controls (mean 93% of predicted; p=0.03). No significant differences were found with regard to either the ratio between forced expiratory volume in 1 s and forced vital capacity or forced expiratory volume in 1 s. The majority of firefighters had diffusing capacity of the lung for carbon monoxide, oscillometry and single-breath nitrogen washout values within the normal ranges. CONCLUSION: AiDA parameters can provide information on early pulmonary peripheral changes that may not be seen with standard techniques used in screening of pulmonary function.