RESPIRATORY HEALTH, LUNG-FUNCTION, AND AIRWAY RESPONSIVENESS IN SCHOOL-AGE SURVIVORS OF VERY-LOW-BIRTH-WEIGHT

The purpose of this study was to deter mine the respiratory symptoms, pulmonary function, and airway reactivity in school-age survivors of v ery-low-birth-weight aid to describe the influence of birth weight and perinatal illness on their pulmonary function. Thirty (of 39) 10- to 11-year-old survivors of very-low-birth-weight (VLBW) recruited at bir th into a prospective longitudinal study of development; 30 (of 32) no rmal-birth-weight peers recruited from the same school or census tract as the VLBW group at age 5; and 15 normal-birth-weight siblings of th e VLBW group participated in the study. Outcome measures were mother's reports of respiratory health; forced vital capacity (FVC), forced ex piratory volume in 1 second (FEV1); FEV1/FVC; forced expiratory flow, midexpiratory phase (FEF25-75); peak expiratory flow rate (PEFR); and tolerance to methacholine, There were no differences between groups in mothers' reports of current respiratory health. Pulmonary function va lues were lower for the VLBW survivors but significant only for FEF25- 75 (F=4.13; P=0.02). Number of days in the intensive care nursery corr elated significantly with decreased FEV1 (r=-.40, df=28, P=0.03), FEV1 /FVC (r=-.37, df=28, P=0.04, and FEF25-75 (r=-.39, df=28, P=0.03). Onl y the relationship between length of nursery stay and FEV1/FVC was ind ependent of birth weight. Number-of days on mechanical ventilation was significantly correlated with decreased FEV1 (-.44, df=28, P=0.01), F EV1/FVC (r=-.38, df=28, P=0.04), FEF25-75 (r=-.44, df=28, P=0.01, and PEFR (r=-.40, df=28, P=0.03). All of these relationships were independ ent of birth weight. There were no significant associations between pe rinatal risk factors and methacholine responsiveness. Differences betw een VLBW children and normal-birth-weight children in pulmonary functi on are modest even when statistically significant. Severity of perinat al illness influences pulmonary function parameters into late childhoo d.