Indication | Pulmonary function test |
Diagnostics# | Restrictive lung disease in older children? Low FEV1 and FVC, FEV1/FVC ratio normal or high, low lung volumes |
bstructive lung disease (PIBO suspected)? Low FEV1, FVC normal or low, FEV1/FVC ratio low, raised lung volumes and resistance | |
Alveolar haemorrhage? Raised DLCO | |
NEHI? Obstructive RVRTC, raised lung volumes | |
chILD with interstitial thickening/fibrosis or prominent involvement of pulmonary vasculature (e.g. hepatopulmonary syndrome)? | |
Low DLCO | |
Disease monitoring | Spirometry in older children |
Recurrent pulmonary haemorrhage: increasing DLCO; progressive fibrosis: decreasing DLCO | |
Cardiopulmonary exercise testing | |
Monitoring extrapulmonary co-morbidities of chILD | Respiratory muscle weakness, e.g. in juvenile dermatomyositis: lying and standing VC, MIP and MEP |
FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; PIBO: post-infectious bronchiolitis obliterans; DLCO : diffusing capacity of the lung for carbon monoxide; NEHI: neuroendocrine cell hyperplasia of infancy; RVRTC: raised volume rapid thoracoabdominal compression; VC: vital capacity; MIP: maximum inspiratory pressure; MEP: maximum expiratory pressure. #: it is not possible to make specific pathological diagnoses from lung function testing, but it may be helpful to direct further diagnostic approach.