William H. Northway

ALTHOUGH hyaline-membrane disease, the respiratory-distress syndrome of the newborn infant, has been the object of increased clinical and research interest in the past ten years, little attention has been paid to its possible sequelae.1 , 2 It is stated that most of these infants who survive the first three days of life will recover completely, and by seven to ten days of life will have normal lungs radiographically.3 , 4 Recent experience with critically ill infants at the Stanford Premature Infant Research Center demonstrates that intensive therapy may modify the acute syndrome so as to permit the development of a previously unrecorded abnormality of . . .

BACKGROUND: Bronchopulmonary dysplasia is a chronic lung disease that often develops after mechanical ventilation in prematurely born infants with respiratory failure. It has become the most common form of chronic lung disease in infants in the United States. The long-term outcome for infants with bronchopulmonary dysplasia has not been determined. METHODS: We studied the pulmonary function of 26 adolescents and young adults, born between 1964 and 1973, who had bronchopulmonary dysplasia in infancy. We compared the results with those in two control groups: 26 age-matched adolescents and young adults of similar birth weight and gestational age who had not undergone mechanical ventilation, and 53 age-matched normal subjects. RESULTS: Sixty-eight percent of the subjects with bronchopulmonary dysplasia in infancy (17 of the 25 tested) had airway obstruction, including decreases in forced expiratory volume in one second, forced expiratory flow between 25 and 75 percent of vital capacity, and maximal expiratory flow velocity at 50 percent of vital capacity, as compared with both control groups (P less than 0.0001 for all comparisons). Twenty-four percent of the subjects with bronchopulmonary dysplasia in infancy had fixed airway obstruction, and 52 percent had reactive airway disease, as indicated by their responses to the administration of methacholine or a bronchodilator. Hyperinflation (an increased ratio of residual volume to total lung capacity) was more frequent in the subjects with a history of bronchopulmonary dysplasia than in either the matched cohort (P less than 0.0006) or the normal controls (P less than 0.0004). Six of the subjects who had bronchopulmonary dysplasia in infancy had severe pulmonary dysfunction or current symptoms of respiratory difficulty. CONCLUSIONS: Most adolescents and young adults who had bronchopulmonary dysplasia in infancy have some degree of pulmonary dysfunction, consisting of airway obstruction, airway hyperreactivity, and hyperinflation. The clinical consequences of this dysfunction are not known.

A retrospective study of 299 successive infants who were ventilated for respiratory distress syndrome (RDS) showed that 62 (21%) developed radiographic stage IV bronchopulmonary dysplasia (BPD). The largest, most mature, and least ill infants tended to survive without developing BPD; the smallest, least mature, and most ill infants tended to die without developing BPD. The patients who developed BPD tended to be intermediate in terms of weight, maturity, and severity of disease; they required longer exposures to elevated oxygen and assisted ventilation than patients who did not develop BPD. The data suggest that in addition to varying individual susceptibility (primarily degree of immaturity and initial severity of disease), elevated oxygen is more important than mechanical ventilation in the pathogenesis of BPD.

A retrospective study of 299 successive infants who were ventilated for respiratory distress syndrome (RDS) showed that 62 (21%) developed radiographic stage VI bronchopulmonary dysplasia (BPD). The largest, most mature, and least ill infants tended to survive without developing BPD; the smallest, least mature, and most ill infants tended to die without developing BPD. The patients who developed BPD tended to be intermediate in terms of weight, maturity, and severity of disease; they required longer exposures to elevated oxygen and assisted ventilation than patients who did not develop BPD. The data suggest that in addition to varying individual susceptibility (primarily degree of immaturity and initial severity of disease), elevated oxygen is more important than mechanical ventilation in the pathogenesis of BPD.