Radiological changes after therapeutic use of surfactant in infants with respiratory distress syndrome.

The aims of this study were to determine the incidence of typical chest radiography findings - (1) uniform improvement, (2) asymmetrical improvement, (3) no improvement or (4) interstitial emphysema - after therapeutic use of surfactant and to analyse clinical course and outcome. Chest radiographs of 138 infants of very low birth weight treated with surfactant were analysed. Twenty-eight infants with a diagnosis other than typical respiratory distress syndrome (RDS), i. e., sepsis, congenital pneumonia and congenital malformation, were excluded. In 110 patients with clinical and radiological evidence of typical RDS (median gestational age 28 weeks, median birth weight 1070 g) adequate chest radiographs from before and within 72 h after surfactant treatment were available. The time of surfactant application ranged between 1 and 12 h after birth. The most common finding after surfactant treatment was uniform or asymmetrical improvement of pulmonary aeration (80 of 110 patients). Patients with uniform clearing had the best long-term outcome. Asymmetrical clearance was often localised on the right side or in central regions of the lung, and usually disappeared after retreatment with surfactant without clinical significance. In 11 patients no change in aeration was found and retreatment was absolutely ineffective. Development of pulmonary inter- stitial emphysema after surfactant treatment was a grave prognostic sign: 73 % of these infants died within the first 2 weeks of life compared with 10 % of those with uniform or asymmetrical improvement of ventilation.