Pulmonary function in bronchopulmonary dysplasia

The purpose of this study was to examine lung function and bronchodilator responsiveness in infants with a history of prematurity and bronchopulmonary dysplasia (BPD), using the raised volume rapid thoracoabdominal compression technique as well as with whole‐body plethysmography. Spirometric measurements were obtained in 28 infants with a history of BPD, defined as preterm birth with O2 requirement at 36 weeks postmenstrual age (gestational age at birth, 26.4 ± 2.1 weeks, mean ± SD; birthweight, 898 ± 353 g; age at study, 68.0 ± 35.6 weeks). Fractional lung volumes were measured in 27 subjects. Values were expressed as percentage of predicted normal values. Compared to normal infants, those with a history of BPD exhibited decreases in forced expiratory flows including forced expiratory volume in 0.5 sec (76.3 ± 19.6%), forced expiratory flow at 75% of expired forced vital capacity (FEF75; 59.5 ± 30.7%), and FEF25–75 (74.0 ± 26.8%; P