Membrane and Capillary Components of Lung Diffusion in Infants with Bronchopulmonary Dysplasia

Abstract

Our findings are consistent with infants with BPD having impaired alveolar development with fewer but larger alveoli, as well as a reduced Vc.

Ventilatory efficiency in children and adolescents born extremely preterm

“…The higher slope of theV E −VCO 2 relationship for EP−born indicates higher dead space ventilation. This could be related to increased ventilation of the anatomical dead space because of shallower breathing at higher breathing frequencies (Chang et al, 2016). There were no differences in the relationship between V T andV E between the groups after adjusting for FEV 1 .…”

“…When born at this early stage, gas exchange must take place in developmentally fetal lungs still in their canalicular or saccular phase, disturbing growth and development (Jobe and Bancalari, 2001). Studies of EP−born children and adolescents report altered acinar structures with fewer and larger alveoli and lower alveolar capillary density, lower dynamic lung volumes, and lower diffusing capacity for carbon monoxide (Cutz and Chiasson, 2008;Satrell et al, 2013;Chang et al, 2016). Most studies on EP-born children and adolescents find lower peak oxygen uptake (VO 2peak ) (Kilbride et al, 2003;Smith et al, 2008;Burns et al, 2009;Welsh et al, 2010;Clemm et al, 2012Clemm et al, , 2014Clemm et al, , 2015.…”

An alternative method to measure the diffusing capacity of the lung for carbon monoxide in infants

“…We used our previously collected and published data demonstrating that infants with BPD had lower DL CO , but did not differ for V A when compared to healthy control infants born full term . No additional infant testing was performed for this protocol.…”

“…Our laboratory previously described a single‐breath technique to assess DL CO in sedated infants, with gas exchange and inert gas equilibration occurring during an induced respiratory pause at an elevated lung volume . This approach has provided important physiologic insights into lung growth and development early in life, as well as physiologic demonstration of impaired parenchymal development in infants with bronchopulmonary dysplasia (BPD) . Using this approach, we also demonstrated impaired gas exchange in infants with interstitial lung disease, as well as the subsequent improvement in DL CO with clinical improvement .…”

Decreased pulmonary capillary volume in adolescents born very preterm

“…In infants, BPD has been associated with lower diffusing capacity of the lung for carbon monoxide (DLCO) values, reflecting gas exchange abnormalities. These lower DLCO values are the consequence of both lower diffusing capacity of the alveolar‐capillary membrane (Dm) and decreased pulmonary capillary blood volume (Vc) . The possibility of Dm and Vc normalisation with growth, particularly by catch up alveolarisation, has not yet been explored in adolescents.…”