Untersuchungen der kleinen Luftwege beim Emphysem

Abstract

The method of the retrograde catheter [8] was applied to measure the peripheral resistance of normal human and emphysematous lungs. Table 1 shows that in emphysema the peripheral resistance can be as high as 40 times the normal values. Emphysema was then graded by the method of Dunnil [4] and Thurlbeck [11] and random sections were taken for measuring MLI [13], ISA [12], and the small airways: Bronchioli smaller than 2 mm Ø were counted, their diameters taken by a method described in detail, and the shrinkage factors calculated. Mucicarmin- and PTAH-staines were done to show mucus plugging. Picture 1 and Table 1 show that in emphysema the total number of small airways is significantly reduced. So is the number of respiratory bronchioli and of airways between 0,5–0,99 mm in diameter, whereas the number of airways<0,5 mm is not (significantly) increased. The total area of small airways is reduced in emphysematous lungs, so is the area of respiratory bronchioli and of airways between 0,5–0,99 mm in diameter. The area of nonrespiratory bronchioli<0,5 mm is significantly increased. Corrections to the predicted individual lung-volume or a constant volume of 5 1 did not change the results. It is not only the loss of number and of total cross sectional area of the small airways that increases peripheral resistance, but the remaining lumen is plugged by mucus. The applied methods are discussed.

There are two causes of the increased peripheral resistance: 1. Loss of cross sectional area of small airways (the cause of increased area is discussed) which is irreversible. 2. Mucus plugging of the small airways, which is reversible. Attention is drawn towards two methods developed lately which allow an early diagnosis of airway disease.

Zusammenfassung

Es wird eine morphometrische Methode zur Untersuchung der kleinen Luftwege beschrieben. Es zeigte sich, daß beim obstruktivem Emphysem der Gesamtquerschnitt und die Zahl der peripheren Luftwege (Ø<2 mm) gegenüber der Norm signifikant verkleinert ist. Ursache der Widerstandserhöhung ist nicht nur der Verlust an Bronchioli und die Einschränkung ihres Gesamtlumens, sondern auch deren Verlegung durch Schleim. Durch diese Ergebnisse gewinnen Untersuchungsmethoden an Bedeutung, mit denen man eine Erkrankung der kleinen Luftwege diagnostizieren kann, wie die Messung der Compliance in Abhängigkeit von der Atemfrequenz und die Bestimmung des Durchblutungs-Belüftungs-Verhältnisses mit¹³³Xe.