A ten-year retrospective study of pink and yellow neonatal hyaline membrane disease.

Since it was first described several years ago, yellow bilirubin staining of the pulmonary membranes in neonatal hyaline membrane disease has apparently become more common. In a retrospective study of neonatal autopsy experience, it was found that as more of the premature infants survived longer, yellow hyaline membrane disease was a more frequent finding, increasing from 7% of all newborns having hyaline membrane disease at autopsy in 1970 to 50% in 1980. In comparing 499 cases with eosinophilic hyaline membranes with 168 cases of yellow membranes, newborns with bilirubin staining of the pulmonary membranes were found to be more premature (P less than .02), had smaller autopsy weight (P less than .002), and survived longer (P less than .00001). When multiple clinical parameters were compared between a group of infants with yellow membranes and a group of infants with pink membranes who were matched for gestational age, year of birth, and length of survival, no differences were found between the two groups. No correlation was found between kernicterus and yellow staining of the pulmonary hyaline membranes in the first years of the study, but there was a strong correlation in the last 5 years, coincident with the increase in the rate of yellow hyaline membrane disease found at autopsy. The gross bilirubin staining of the brain was the secondary type of kernicterus, not toxic bilirubin encephalopathy. The observation of bilirubin staining in the lung and in the brain correlates with prolonged survival in some very small premature infants. This does not appear to be a manifestation of bilirubin toxicity, but rather a marker of prior tissue damage.