Early dynamic pulmonary compliance and bronchopulmonary dysplasia in preterm newborn infants

OBJECTIVES: to evaluate whether early pulmonary compliance could be a predictor of the presence of bronchopulmonary dysplasia at 28 days of life in preterm infants. METHODS: a cohort study was carried out involving neonates with gestational age <32 weeks and a birth weight of 500-1250 g receiving prophylactic surfactant at 30 minutes of life. The lung mechanics was evaluated using a pneumotachograph connected to the ventilator circuit 60 minutes after birth. Flow signals and volume were measured using WinTracer® in order to determine the dynamic pulmonary compliance and the airway resistance. Variables associated with the need for oxygen or assisted ventilation at 28 days were assessed using logistic regression. RESULTS: 32 neonates were enrolled in the study and 25 survived until the 28th day, at which point 17 (68%) needed assisted ventilation and/or oxygen (Group 1), and 8 did not (Group 2). The Group 1 infants were younger, had higher clinical risk index scores and frequency of patent ductus arteriosus. The lung mechanics in the 1st hour of life was similar in Groups 1 and 2. Regression analysis showed that bronchopulmonary dysplasia was associated with the presence of patent ductus arteriosus and lower gestational age. CONCLUSIONS: pulmonary compliance figures in the 1st hour of life did not predict the presence of bronchopulmonary dysplasia in the 28th day of life of the studied population.OBJETIVOS: avaliar se a complacência pulmonar precoce é fator preditor da presença de displasia broncopulmonar aos 28 dias de vida, em prematuros. MÉTODO: coorte prospectiva de neonatos com idade gestacional