Lungenfunktionsverfahren zur Beurteilung der kleinen Atemwege

The noninvasive assessment of peripheral airway function includes the interplay of various procedures. In healthy lungs the peripheral airways only make a minor contribution to total airway resistance. In lung disease this proportion can substantially increase but is often not detected in spirometry. Particularly early functional alterations of the lungs comprise several pathomechanisms including airflow limitation, hyperinflation, air trapping, loss of elasticity, emphysema, ventilation inhomogeneities and inflammation. Spirometric parameters predominantly represent flow limitations during forced breathing maneuvers. For assessment of hyperinflation, spirometry can be supplemented by body plethysmography. In addition to the ventilation, transfer factor and fractional exhaled NO also include information on diffusion, perfusion and inflammation. Tidal breathing oscillometry, represents a promising and simple procedure for the identification of increases in peripheral resistance and alterations in elasticity. Using easily applicable capnovolumetry can assess ventilation inhomogeneities and emphysema. Other pathophysiological insights are gained using gas washout procedures. However, these remain reserved for research questions due to their complexity. The new procedures have the potential to provide additional information to the currently used standard diagnostics and to enable a differentiated assessment of small airway dysfunction.