Correlation Between Lung Function and Tracheobronchial Collapse

Abstract

In 30 unselected male patients, bronchoscopic aspect and lung function parameters (notch in FEV₁, FEV₁/FIV₁%, discrepancy between airways resistance and FEV₁; club-shaped resistance curves) were correlated to determine the validity of lung function in the diagnosis of a central bronchial collapse. There were no strong correlations; only the club-shaped resistance curve and FEV₁/FIV₁% < 60 were a little more often seen in the presence of central bronchial collapse. It is concluded from these results, and with regard to the known results from bronchial pressure measurements, that the functional parameters mentioned above are good indicators of a flaccid tracheobronchial system but not typical for a central bronchial collapse alone. Additional methods (bronchoscopy, bronchial pressure measurements) are needed to locate the major pressure drop and to select the adequate therapy (conservative in the case of pure peripheral or most mixed situations, chirurgical in special cases with pure central bronchial collapse). The reactions of a collapsible tracheobronchial system to bronchodilating drugs are described and their help in location of the major pressure drop is discussed.

Pulmonary Function and Flow-Volume Loop Patterns in Patients with Tracheobronchomalacia

“…22 Reinert and Steurich also found no strong correlations between central airway collapse and lung function parameters in 30 unselected male patients. 18 Consistent with this observation, previous studies have shown that clinical improvement after central airway stabilization is not always associated with an increase in FEV 1 . 8,9 The low mean D LCO seen in our study is likely explained by the high prevalence of parenchymal lung disease in this patient population.…”

“…15 Reinert and Steurich were unable to correlate this pattern with central bronchial collapse. 18 The finding of reproducible notching in only 7 subjects in our study suggests that this is not a particularly reliable indicator of TBM.…”

Tracheobronchomalacia and excessive dynamic airway collapse

“…TBM is also referred to in the literature, however, as tracheobronchial collapse, 3,4 expiratory tracheobronchial collapse, expiratory tracheobronchial stenosis, 2 tracheobronchial dyskinesia, 5 or described as dynamic airway collapse (DAC) 1,6–9 . This contributes to some confusion regarding these distinct entities.…”

“…These findings are neither sensitive nor specific. Overall, few studies rigorously report results of PFTs in patients with TBM or EDAC 2–4,77–79 . In addition, differences in methodology and disease definition are responsible for considerable variability among those studies that do describe findings 2,79…”

Description of a multidimensional classification system for patients with expiratory central airway collapse

“…A common framework such as that provided by a multidimensional classification system is useful in describing patients with expiratory central airway collapse. Additional studies are required to determine whether pulmonary function testing might also have a place within this classification because diminished expiratory flow, a biphasic flow‐volume loop, 20 or flow oscillations 21 noted in some patients are non‐specific 22–24 . From an airway imaging perspective, dynamic CT or cine MRI could be used instead of, or in addition to, bronchoscopy, in order to determine origin as well as to map out the morphology, severity and extent of the disease process, because good correlation has been noted between bronchoscopic findings and these new imaging techniques 12–15,25,26 …”