Hyaline membrane disease: A pathological study of 55 infants

Abstract

A detailed analysis has been made of the pathological lesions in the lungs of 55 human newborn infants with hyaline membrane disease. The highest incidence in this series was in the groups of foetal age, 29-30 weeks. At necropsy, a hydrostatic lung test was often negative. The inconsistency of this test as evidence of live-birth is re-emphasized. Histology included total sections of the different lung lobes. In addition to the accepted lesions of hyaline membrane disease, this study stresses the following features. (1) Localized areas of interstitial emphysema in 7 babies who were relatively mature. This may be the result of the greater force of their inspiratory movements. (2) Hyaline membranes were less extensive and less developed in the very young premature age-group (less than 28 weeks). (3) Pulmonary oedema was almost constant. (4) Localized or extensive pulmonary haemorrhages were present in approximately half the cases, and were thought to be a terminal complication. (5) Aspiration of amniotic fluid was usually not impressive; when present, it did not correlate with the extent of the hyaline membranes. In addition, two previously undescribed features have been observed. The hyaline membranes are directly apposed to the reticular fibres of the alveolar walls and alveolar ducts which they line, suggesting a superficial necrosis of the walls of alveoli and alveolar ducts in hyaline membrane disease. The lymphatic vessels of the lungs were in most cases distended with fluid and often appeared angiectatic and congested. This, and the pulmonary oedema, are in keeping with the concept of an abnormal alveolo-capillary transudation in hyaline membrane disease.