[The different sequelea of hyaline membranes in the adult and in the newborn (author's transl)].

The sequelae of pulmonary hyaline membrane in the newborn and in the adult are demonstrated. At both ages the forming and the increased cellularity of the alveolar interstitium are identical. The latter is accompanied by a reduction of the number of capillaries and tends to change into interstitial fibrosis. The further outcome of the intraalveolar exudate is different: in the newborn the hyaline membranes are completely dissolved whereas they are organized in the adult. In the late stages of this process the lung of the newborn shows varying diameters of alveoli and squamous metaplasias of the bronchiolar epithelium. These changes are known as bronchopulmonary dysplasia and impress as honey-comb lung in x-ray. As explanations of the different reactions to pulmonary hyaline membranes preexisting damage in the lung of the adult, a different function of the macrophage system, a different resistance against toxins, disturbances of blood circulation and the postnatal continuing growth of the lung of the newborn are discussed.