ROLE OF HYALINE MEMBRANES, BLOOD, EXUDATE, EDEMA FLUID AND AMNIOTIC SAC CONTENTS IN PREVENTING EXPANSION OF THE LUNGS OF NEWBORN INFANTS

Abstract

The lungs of 43 infants were removed at autopsy and expanded with measured amounts of negative pressure. The amounts of pressure required to initiate expansion and to bring about apparent complete expansion of the gross specimens could not be correlated with the final degree of expansion that was obtained as measured by the thickness of the alveolar walls. Expansibility of the lungs was impeded in two groups: those with a birth weight less than 1200 gm. and those who had extensive hyaline membranes in the lungs. The presence of amniotic sac contents, blood, exudate and edema fluid in the alveoli and air passages, even in large amounts, did not mechanically prevent what appeared to be satisfactory expansion of the lungs.