The validity of static lung compliance in asbestos-induced diseases

Pulmonary compliance can be viewed as an indicator of distensibility of the lungs, not only in asbestos-induced pulmonary disorders but also in visceral pleural fibrosis extending into the lung parenchyma. In this study we evaluated static compliance measurements in asbestos-derived diseases, especially in patients with parietal pleura plaques. Lung function analyses, especially static lung compliance, were correlated with high-resolution computer tomography examinations.

Sixty-three patients with parietal pleural plaques, 10 with visceral pleural fibrosis, 39 with parenchymal pulmonary asbestosis together with parietal pleural plaques, and 42 with parenchymal pulmonary asbestosis together with visceral pleural fibrosis were enrolled in the study.

In comparison with patients having only parietal pleural plaques, those having asbestosis and visceral pleural fibrosis showed significant decreases in static lung compliance, diffusing capacity, and vital capacity. Visceral pleural thickening was also associated with significantly reduced FEV(1), MEF(50), and FEV(1)/FVC ratios. Multiple regression analyses indicated that the existence of visceral pleural fibrosis (p = 0.017) is the most important factor accounting for a decrease in static compliance. Reference values of static lung compliance differ notably. In comparison with mean reference values, the sensitivity of detecting reduced lung compliance was calculated to be between 9.7 and 45.5 %. Other respiratory function variables failed to show any significant differences.

Our data indicate that the measurement of static compliance is not sufficient for early detection of pulmonary function impairment in patients with parietal pleural plaques.