RISK-FACTORS FOR HYPERINFLATION IN YOUNG SCHOOLCHILDREN BORN PREMATURELY

Lung function abnormalities, including hyperinflation, are common in y oung children born prematurely. The aim of this study was, in such pat ients, to determine factors associated with hyperinflation, that is an elevated lung volume. Lung volume was estimated by measuring function al residual capacity (FRC) before and after bronchodilator therapy in 41 5-year-old children who had been born prematurely at a median of 30 weeks gestational age. Hyperinflation was defined as an FRC greater t han 120% of that predicted for height and a positive bronchodilator re sponse as a greater than or equal to 10% change in FRC. Twelve (29%) o f the children were symptomatic at 5 years, their median FRC (132%) wa s significantly higher than that of the asymptomatic children (109%), P < 0.01. Twelve (29%) children were hyperinflated; a greater proporti on of the hyperinflated compared to the non-hyperinflated patients wer e symptomatic at 5 years (7 or 58% versus 5 or 17%) (P < 0.05) and res ponded to bronchodilator therapy (9 or 75% versus 4 or 14%) (P < 0.01) . Regression analysis demonstrated that hyperinflation related signifi cantly only to current symptom status, but not perinatal variables. Co nclusion Hyperinflation in young children born prematurely reflects cu rrent symptom status and not adverse neonatal events.