Longitudinal measures of lung function in infants with bronchopulmonary dysplasia

Abstract

SUMMARY We previously demonstrated that infants with a history of bronchopulmonary dysplasia (BPD) exhibit airflow obstruction and air trapping. The purpose of this study was to assess longitudinal changes in pulmonary function in infants with a history of BPD over the first three years of life, and the relationship to somatic growth. Spirometry was measured using the raised volume rapid thoracoabdominal compression technique, and lung volumes measured by plethysmography. Eighteen infants (mean gestational age±SD 27.3±2.2 weeks, birthweight 971±259 g) underwent two lung function studies. Average age at first test was 58.8 wks. Spirometry demonstrated significant reductions in forced expiratory volume in 0.5 sec (FEV0.5, 76.0±15.9% predicted, Z score −2.13±1.69), forced expiratory flow at 75% of expired forced vital capacity (FEF75, 54.8±31.1%, −3.58±2.73) and FEF25–75 (67.8±33.3%, −1.79±1.76). Group mean total lung capacity (TLC) was in the low normal range (82.9±13.5% predicted) and residual volume (RV)/TLC was mildly elevated (122.4±38.2% predicted). Repeat testing was performed an average of 32.7 weeks after initial testing. At re-evaluation, group mean lung volumes and flows tracked at or near their previous values; thus, in general, there was a lack of catch-up growth. However, compared to infants with below average or average somatic growth (as represented by gm/day), infants with above average growth showed significantly greater improvements in percent predicted FVC, FEV0.5, TLC and RV/TLC (all p<0.05, ANOVA). We conclude that longitudinal measures of pulmonary function in infants and young children with BPD demonstrate significant airflow obstruction and modest restriction which tends to persists with time. On the other hand, infants with above average somatic growth showed greater lung growth than their peers. Additional studies examining the effects of various nutritional regimens on lung function are warranted.

Understanding the Short- and Long-Term Respiratory Outcomes of Prematurity and Bronchopulmonary Dysplasia

“…Seventeen papers were identified that evaluated pulmonary outcomes of preterm infants within the first 5 years of life (21,26,27,30,31,33,40,46,47,51,55,58,61,64,65,73,74). Varying definitions of BPD were used in these studies, with some defining BPD as persistent oxygen use at 28 days of age and others defining BPD based on an assessment at 36 weeks postmenstrual age.…”

Impact of bronchopulmonary dysplasia on pulmonary function during childhood: a systematic review

“…Of the 22 articles included (table 1), 12 assessed children with a history of BPD at different moments (longitudinal) [7][8][9][10][11][12][13][14][15][16]27,28 and the maximum follow-up was the interval between the neonatal hospital stay and five years of life. The remaining ten reviewed studies performed pulmonary function testing in one single moment (transversal).…”

“…However, these alterations may not be significant considering the normal values of pulmonary function parameters 12,17 . In this context, some authors 7,8,10 point out that improved pulmonary function during infancy is more evident in children with moderate/severe BPD, compared to those with mild BPD, or in preterm infants without BPD 28 . It is well-established that some complications caused by BPD in early childhood may favor high rates of respiratory infections, recurrent wheezing and hospital readmissions 12,28,33,34,36 .…”

“…In this review, the studies suggest that respiratory symptoms and pulmonary function seem to improve in early childhood 7,8,10,12,27 with the growth and development of the child with a history of BPD. Farstad et al 12 found that, at 50 weeks of corrected age (CA), 80% of the children with BPD in their study sample had severe peripheral obstruction, compared to 58% of preterm infants without BPD.…”

“…Currently, pulmonary function testing in early childhood, i.e., the time period ranging from 0 to 6 years including infants and preschoolers, can be performed by examinations, such as rapid chest compression, single breath occlusion, plethysmography and helium dilution 6 . Studies indicate that infants with BPD show compromised pulmonary function in the first years of life, with significant expiratory flow limitation, namely, forced expiratory volume in one second (FEV1), mean forced expiratory flow (FEF25-75%), as well as reduced pulmonary compliance, increased pulmonary resistance, higher respiratory rate, reduced functional residual capacity (FRC) and residual volume [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] . These results are characteristics of ventilatory and functional changes, the knowledge of which may provide a better understanding of the disease and, consequently, improve treatment and preventive strategies to manage the disease.…”