THE EFFECTS OF THE OCCURRENCE OF MILD BRONCHIOLITIS ON LUNG FUNCTION

Abstract

Bronchiolitis requiring hospitalization during infancy is reported to result in decrements of lung function suggestive of small airways dysfunction. The purpose of this study was to evaluate the effects of a history of mild bronchiolitis not requiring hospitalization in a group of children enrolled in day care and followed longitudinally from early infancy. Fifty-six black children (30 girls, 26 boys) had all illnesses documented clinically and etiologically, then were trained to perform spirometry at 2 1/2 years of age. Regression analyses were performed on MEFV parameters over the height range 90-130 cm using these measurements as dependent and height as independent variables. The FEF25-75% and Vmax50% in children who ever had bronchiolitis (n=27) were significantly reduced and about 300 ml/sec below the flows for children who had never had bronchiolitis but the slopes of the regressions were not different for the 2 groups; there were no differences in mean values or slopes for the regressions of FVC or FEV1 nor between girls and boys. These data demonstrate that black children who have had mild bronchiolitis have decrements in flow rates at low lung volumes as early as 3 years of age and that this change persists during early childhood. Since the flow rate decreases were constant over the height range studied, they may represent a fixed effect of acute injury or constitutional differences.