title: Long-term pulmonary consequences of respiratory distress syndrome in preterm infants treated with exogenous surfactant.
abstract: The pulmonary outcome for preterm infants 1 year after synthetic surfactant replacement for respiratory distress syndrome was assessed by examining their pulmonary status and the results of pulmonary function tests. A total of 47 infants were followed: 13 infants mean +/- SD: birth weight, 1960 +/- 616 gm; gestation, 32 +/- 1.1 weeks) had been assigned to the placebo group and 34 (birth weight = 1890 +/- 530 gm; gestation = 32 +/- 2.5 weeks) to surfactant treatment. The infants were examined at 3 to 6 months of age (n = 45) and at 9 to 12 months of age (n = 36). There were no significant differences between the two groups in predisposing clinical conditions that would lead to chronic lung disease. The infants had similar patterns of growth, respiratory-related illness, and need for theophylline therapy, diuretic therapy, or both. None had hypoxemia by pulse oximetry. Mean (+/- SEM) values for pulmonary mechanics and energetics in surfactant-treated infants were significantly (p < 0.01) lower for total pulmonary resistance in late infancy (57.7 +/- 11.7 vs 35.3 +/- 4.6 cm H2O/L per second). Lower values (mean +/- SEM) of resistive work of breathing were also measured in the surfactant-treated group (60.7 +/- 12.0 vs 38.2 +/- 3.6 gm-cm/kg per breath). The dynamic pulmonary compliance values were in the low-normal range for both groups, and the mean (+/- SEM) peak-to-peak esophageal pressure values were elevated (11.47 +/- 2.26 cm H2O in the placebo group; 9.24 +/- 0.69 cm H2O in the surfactant group). Forced expiratory flow measurements in late infancy demonstrated significant (p < 0.01) improvement in expiratory reserves and reduced evidence of airflow obstruction in the surfactant-treated infants (peak flow (mean +/- SEM): 287.1 +/- 69 vs 396.9 +/- 27 ml/sec; forced expiratory flow (mean +/- SEM) at functional residual capacity: 56.3 +/- 7.5 vs 83.4 +/- 19.5 ml/sec). No significant differences in pulmonary functions were noted in early infancy. These data suggest that surfactant replacement for respiratory distress syndrome may be associated with beneficial long-term effects on the resistive airflow properties of larger preterm infants.
authors.affiliation: Neonatal Pulmonary Laboratory, Pennsylvania Hospital, Philadelphia 19107.
authors.forename: S
authors.initials: S
authors.lastname: Abbasi
authors.forename: V K
authors.initials: VK
authors.lastname: Bhutani
authors.forename: J S
authors.initials: JS
authors.lastname: Gerdes
mesh_terms: D004338:Drug Combinations; D005233:Fatty Alcohols / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008171:Lung Diseases / Q000209:etiology*; D008297:Male; D010767:Phosphorylcholine; D011092:Polyethylene Glycols / Q000627:therapeutic use*; D011663:Pulmonary Surfactants / Q000627:therapeutic use*; D012127:Respiratory Distress Syndrome, Newborn / Q000150:complications* / Q000188:drug therapy* / Q000503:physiopathology; D012129:Respiratory Function Tests; D016896:Treatment Outcome
chemical_list: D004338:Drug Combinations; D005233:Fatty Alcohols; D011663:Pulmonary Surfactants; D010767:Phosphorylcholine; D011092:Polyethylene Glycols; C047049:dipalmitoylphosphatidylcholine, hexadecanol, tyloxapol drug combination