Long‐term pulmonary functional outcome of bronchopulmonary dysplasia and premature birth

Pulmonary function and exercise tolerance were evaluated in late childhood in two groups of prematurely born children: one group with bronchopulmonary dysplasia (BPD) [n] = 15; gestational age at birth (GA): 29.6 ± 2.8 weeks; birth weight (BW): 1,367 ± 548 g; age at test: 7.9 ± 0.6 years, and a second group without significant neonatal lung disease [pre-term (PT)] (n = 9; GA: 30.3 ± 1.7 weeks; BW: 1,440 ± 376 g; age at test: 7.8 ± 0.22 years). The results were compared with a control group of children of similar ages and heights, born at term [term born (TB)]. We observed that total lung resistance (RL) was significantly higher in BPD (11 ± 3 cmH2O/L/s), and in PT (9 ± 2) than in TB [5 ± 1; (P < 0.001 and P < 0.05, respectively)]. In BPD RL was higher than in PT (P < 0.05). Dynamic lung compliance (CLdY) was decreased in BPD (43 ± 11 mL/cmH2O) and in PT (56 ± 17) compared with TB (76 ± 20) (P < 0.001 and P < 0.05), and also in BPD compared with PT (P < 0.05). Forced expiratory volume in 1 second (FEV1) and FEV1/forced vital capacity (FVC) were lower in BPD (1.07 ± 0.15 L and 72 ± 7%) than in PT (1.29 ± 0.23 L, and 80 ± 7%) (P < 0.05). Exercise tests were performed in six boys with BPD. The ratio between minute ventilation at maximal workload (VEmax ) and the predicted value of maximal voluntary ventilation (MVV) was elevated in the six BPD boys tested, compared with five boys of Group 2 and five TB boys (87 ± 15% vs. 62 ± 14% and 65 ± 13%) (P < 0.05). We conclude that: (1) prematurity and BPD is followed by long-term airway obstruction and a mild degree of exercise intolerance and; (2) premature birth without BPD may be followed by a milder degree of airway obstruction in childhood than in infants who developed BPD during the neonatal period. Pediatr Pulmonol. 1995; 20:289–296. © 1995 Wiley-Liss, Inc.