Pulmonary function using impulse oscillometry system and clinical outcomes at age 4 years in children born extremely preterm with or without bronchopulmonary dysplasia

Abstract

This study aimed to describe the early assessment of lung function and respiratory morbidity in children born extremely preterm with or without bronchopulmonary dysplasia (BPD). MethodsThis was a prospective study including all the children born at gestational age ≤28 weeks who received treatment in the NICU of the Centre Intercommunal de Créteil in France, from January 2006 to March 2012. Lung function, using the impulse oscillometry system, respiratory morbidity and growth were assessed at age 4 years. Lung function and clinical course of children were compared in children with and without BPD. ResultsWe included 136 extremely premature children; 26 (19 %) had BPD. Children with and without BPD did not significantly differ in resistance measurements at 5 Hz (R5) and 20 Hz (R20) and reactance (X5) measurements at age 4 years. A total of 104 (76 %) pre-term children had respiratory resistance R5 above the 95th percentile for the reference population (z-score >1.64), regardless of BPD status. The mean (SD) R5 z-score for all children was 2.1 (±0.7), whereas the mean (SD) R20 was in the normal range (z-score = 1.1 [±0.3]). After treatment with bronchodilators, all children showed no significant change in resistance. The prevalence of asthma symptoms at age 4 years was common and estimated at 30 % regardless of BPD status. ConclusionEarly assessment of lung function by the impulse oscillometry system revealed that most preschool children who were born extremely preterm had abnormal total airway resistance regardless of BPD status. The system is an essential tool for the early assessment of children born prematurely.