UNLABELLED: Lung function abnormalities, including hyperinflation, are common in young children born prematurely. The aim of this study was, in such patients, to determine factors associated with hyperinflation, that is an elevated lung volume. Lung volume was estimated by measuring functional 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 than 120% of that predicted for height and a positive bronchodilator response as a greater than or equal to 10% change in FRC. Twelve (29%) of the children were symptomatic at 5 years, their median FRC (132%) was significantly higher than that of the asymptomatic children (109%), P < 0.01). Twelve (29%) children were hyperinflated; a greater proportion of the hyperinflated compared to the non-hyperinflated patients were symptomatic at 5 years (7 or 58% versus 5 or 17%) (P < 0.05) and responded to bronchodilator therapy (9 or 75% versus 4 or 14%) (P < 0.01). Regression analysis demonstrated that hyperinflation related significantly only to current symptom status, but not perinatal variables. CONCLUSION: Hyperinflation in young children born prematurely reflects current symptom status and not adverse neonatal events.
UNLABELLED: Lung function abnormalities, including hyperinflation, are common in young children born prematurely. The aim of this study was, in such patients, to determine factors associated with hyperinflation, that is an elevated lung volume. Lung volume was estimated by measuring functional 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 than 120% of that predicted for height and a positive bronchodilator response as a greater than or equal to 10% change in FRC. Twelve (29%) of the children were symptomatic at 5 years, their median FRC (132%) was significantly higher than that of the asymptomatic children (109%), P < 0.01). Twelve (29%) children were hyperinflated; a greater proportion of the hyperinflated compared to the non-hyperinflated patients were symptomatic at 5 years (7 or 58% versus 5 or 17%) (P < 0.05) and responded to bronchodilator therapy (9 or 75% versus 4 or 14%) (P < 0.01). Regression analysis demonstrated that hyperinflation related significantly only to current symptom status, but not perinatal variables. CONCLUSION: Hyperinflation in young children born prematurely reflects current symptom status and not adverse neonatal events.