Search

Bronchopulmonary dysplasia (BPD) is the most significant respiratory complication of prematurity, and its consequences last from birth into adulthood. Unfortunately, the dramatic improvements in the management of premature infants have not led to a decreased incidence of BPD, or to breakthroughs in treatments offered for this long-lasting chronic respiratory disorder. Over recent decades the pathological picture of BPD has changed from inflammation, interstitial fibrosis and emphysema attributed to volu-, barotrauma and oxygen toxicity to larger, simplified alveoli and dysmorphic vessels related to arrested alveolarization and vasculogenesis with inflammation maintaining a central role. Corticosteroids (CSs) play a key role in the development of respiratory epithelial cells and lung maturation. These potent anti-inflammatory agents have long been used for the prevention and treatment of BPD; however, the risk/benefit ratio of their use remains unresolved. CSs administered antenatally have contributed to reduce mortality and respiratory distress syndrome, no such effect on BPD reduction has been observed. Postnatal systemic CSs reduced the rate and severity of BPD, yet their long-term neurodevelopmental and respiratory consequences markedly limit routine administration. This is the first in a two-part State-of-the-Art series that reviews the latest relevant clinical trials investigating the short-term and long-term effects of CSs in the prevention and treatment of BPD.

SUMMARY. Background:Lungfunctiondatainhealthynewborninfantsarescarcelargelydueto lack of suitable techniques, although data for developmental and prenatal exposure studies are much needed. We have modified the forced oscillation technique (FOT) for the measurement of respiratory mechanical impedance (Zrs) in unsedated sleeping infants in the first 3 days of life. Methods: Zrs was measured during 30-s epochs of quiet sleep in term neonates born via spontaneous vaginal delivery with a non-invasive FOT between 8 and 48Hz. Total respiratory resistance (R), compliance (C) and inertance (I) were obtained by fitting Zrs spectra. Cluster analysis was used to determine a set of minimal Zrs spectra representing optimal respiratory mechanics for each infant. Results: Successful measurements were obtained in each of the first 3 days in 30/38 (78.9%) neonates. Group mean (� SD) values of R, C, I, and resonant frequency pooled for the 3 days were 45.9 � 16.6hPasL � 1 , 0.97 � 0.21mlhPa � 1 , 0.082 � 0.031hPas 2 L � 1 and 19.2 � 3.2Hz, respectively. Within-session variability represented by coefficient of variation was 5.34 � 3.18% for R and 13.80 � 8.57% for C. Greater between-session variability was observed for the individual infants; however, the only statistically significant change over time was a 13% increase in R from day 1 to day 2. Parameter interdependence was significant (r 2 ¼0.63) between R and I reflecting thelarge contribution of theupper airways to the total Zrs. Conclusions: Noninvasive measurement of Zrs can be made in neonates during natural sleep with a high success rate, even in the first hours of life. Pediatr Pulmonol. 2014 Wiley Periodicals, Inc.