Clinical Determination of Airway Closure, Comparison of Three Methods in Patients with Lung Fibrosis

Publisher Website
Google Scholar
Abstract
35 patients with histologically confirmed lung fibrosis by lung biopsy underwent pulmonary function tests. They included whole body plethysmography, flow volume curves, single breath DLco, blood gas analysis and ‘closing point’ determinations by three different methods: differential whole body plethysmography, simultaneous helium bolus and oxygen single breath dilution methods. Our results in normal subjects and in patients with lung fibrosis allowed us to distinguish between patients with and without coexistent small airway disease. There is a good correlation between direct and indirect methods of measuring the ‘closing point’, but a poor reproducibility. The patients with pure lung fibrosis showed small closing volumes (CV) and closing capacities (CC). The difference of FRC-CC was positive in all cases. The closing capacity did not increase with age in patients with lung fibrosis. CC/TLC appears more sensitive than CV/VC for detecting asymptomatic early peripheral airway obstruction. No correlation was found between FRC-CV and the degree of hypoxia at rest. In pure lung fibrosis, altered regional distribution of lung volumes (RV, VC) could explain why we did not find any difference between N2 and helium closing points as in normal subjects. An increased elastic recoil of the lung would explain the abnormally low closing points.

This publication has 4 references indexed in Scilit: