Lungenfunktionsanalytische Differenzierung von Stenosen im Bereich der großen Atemwege

Abstract

The different pathophysiological mechanisms involved in producing airflow obstruction at different sites in the tracheobronchial tree enable their differentiation by means of pulmonary function tests. These tests include volume-time measurements at forced in- and expiration, flow-volume measurements forced in- and expiration and flow-pressure measurements in the bodyplethysmograph during quiet breathing. In 23 patients with localized stenosis of the central tracheobronchial tree (12 with extra-thoracic tracheal stenosis, 4 with intrathoracic tracheal stenosis and 7 with main bronchus stenosis) the following parameters proved to be of diagnostic value: In the differential diagnosis of intra-extra-thoracic tracheal stenosis the forced in-expiratory flow-volume curve, in main bronchus stenosis the plethysmographically obtained flow-pressure curve with a large phase lag at zero flow ("trapped air"). In extreme cases the qualitative analysis of the spirogram in connection with the static lung volumes can be diagnostic.

Effects of Surgery on Airway Mechanics in Tracheal Stenosis

“…In extrathoracic stenosis, forced inspiratory volume in 1 s (FIV,) and the ratio of forced expiratory and inspiratory volume in 1 s (FEV,/F1V,) are well suited for assessment of disturb ances [1,2,9,15].…”

“…The analysis of configuration of body plethysmographic pressure-flow relation al lows the exact localization of upper airway narrowing [19], whereby the s-like shape of the resistance loop without signs of phase displacement is obligatory for extrathoracic stenosis [15,17]. Similarly, the flow-volume curve is mostly egg-shaped [21] and the maximal inspiratory flow (V m .ix .in s p .)…”