Infants with recurrent lower respiratory tract symptoms - who benefits of extensive investigations?
European Respiratory Review
WINNING ABSTRACT: There is limited information on lung function and exhaled nitric oxide fraction (FeNO) in infants with recurrent lower respiratory tract symptoms. In 2000 recurrently symptomatic infants were referred to a tertiary center for further investigation. As part of the clinical investigation, whole-body plethysmography, tidal FeNO measurements, and skin prick tests were performed. In addition, 77 (38%) of the children underwent bronchoscopy. Increased work of breathing in clinical
... thing in clinical examination (in 22%), and abnormal chest radiograph (in 30%), were associated with decreased airway conductance (sGaw z-score f-1.65) (p,0.001 and p50.048, respectively) and hyperinflation of the lungs (FRC z-score o1.65)(p50.004 and p50.038, respectively). Exposure to environmental tobacco smoke (ETS) was associated with FeNO o40 ppb (p50.009). Increased work of breathing, sGaw z-score f-1.65, and FRC z-score o1.65, were associated with low FeNO (p50.002, p50.005, p50.026, respectively). A definitive diagnosis was made in 184 (92%) children; asthma was diagnosed in 149 (74%), infection in 23 (11%), and a structural abnormality in 12 (6%). Abnormal findings in clinical examination predicted the diagnosis of asthma or a structural abnormality in 96% of cases, whereas in children with underlying respiratory infection or no definitive diagnosis, clinical examination was normal in 92% (p,0.001). In conclusion, clinical findings of bronchial obstruction predict well lung function and the diagnosis of asthma in recurrently symptomatic infants. FeNO is affected by ETS exposure, clinical state of the child, and the used methods, and the information obtained should be interpreted with care.