RT Journal Article
SR Electronic
T1 Altered breathing mechanics and ventilatory response during exercise in children born extremely preterm
JF Thorax
JO Thorax
FD BMJ Publishing Group Ltd and British Thoracic Society
SP 1012
OP 1019
DO 10.1136/thoraxjnl-2015-207736
VO 71
IS 11
A1 J E MacLean
A1 K DeHaan
A1 D Fuhr
A1 S Hariharan
A1 B Kamstra
A1 L Hendson
A1 I Adatia
A1 C Majaesic
A1 A T Lovering
A1 R B Thompson
A1 D Nicholas
A1 B Thebaud
A1 M K Stickland
YR 2016
UL http://thorax.bmj.com/content/71/11/1012.abstract
AB Background Extreme preterm birth confers risk of long-term impairments in lung function and exercise capacity. There are limited data on the factors contributing to exercise limitation following extreme preterm birth. This study examined respiratory mechanics and ventilatory response during exercise in a large cohort of children born extremely preterm (EP).Methods This cohort study included children 8–12 years of age who were born EP (≤28 weeks gestation) between 1997 and 2004 and treated in a large regionalised neonatal intensive care unit in western Canada. EP children were divided into no/mild bronchopulmonary dysplasia (BPD) (ie, supplementary oxygen or ventilation ceased before 36 weeks gestational age; n=53) and moderate/severe BPD (ie, continued supplementary oxygen or ventilation at 36 weeks gestational age; n=50). Age-matched control children (n=65) were born at full term. All children attempted lung function and cardiopulmonary exercise testing measurements.Results Compared with control children, EP children had lower airway flows and diffusion capacity but preserved total lung capacity. Children with moderate/severe BPD had evidence of gas trapping relative to other groups. The mean difference in exercise capacity (as measured by oxygen uptake (VO2)% predicted) in children with moderate/severe BPD was −18±5% and −14±5.0% below children with no/mild BPD and control children, respectively. Children with moderate/severe BPD demonstrated a potentiated ventilatory response and greater prevalence of expiratory flow limitation during exercise compared with other groups. Resting lung function did not correlate with exercise capacity.Conclusions Expiratory flow limitation and an exaggerated ventilatory response contribute to respiratory limitation to exercise in children born EP with moderate/severe BPD.