Childhood Interstitial Lung Disease Standardised Operating Procedure – Bronchoscopy and BAL

This information paper from Lung Foundation Australia and chILDRANZ outlines a standardised operating procedure for bronchoscopy and bronchoalveolar lavage (BAL) in children being investigated for childhood interstitial lung disease (chILD). The resource is designed for use by paediatric respiratory specialists and healthcare professionals involved in diagnosing complex lung conditions. It provides best-practice guidance for conducting flexible fibreoptic bronchoscopy (FFB), typically performed under sedation or general anaesthesia, and delivering BAL to aid differential diagnosis. The document stresses the importance of preventing contamination of samples with upper airway flora and details the correct procedural steps depending on whether access is via endotracheal tube, laryngeal mask or facemask.

The primary role of BAL in chILD patients is to exclude infection and investigate for conditions such as pulmonary alveolar proteinosis, hypersensitivity pneumonitis, pulmonary haemorrhage, and aspiration syndromes. The document includes a diagnostic table summarising characteristic BAL findings such as hemosiderin-laden macrophages (indicating alveolar haemorrhage), PAS-positive material (suggestive of alveolar proteinosis), and lipid-laden macrophages (linked to aspiration). Additional findings like BAL eosinophilia, neutrophilia or lymphocytosis can help narrow the differential diagnosis and guide further testing for interstitial lung disease, drug reactions, or autoimmune and infectious causes.

Site selection for BAL should be based on high-resolution CT imaging, particularly in diffuse lung disease, and BAL should not be performed in a lobe selected for lung biopsy during the same session. The resource also notes the potential role of flow cytometry in analysing BAL lymphocyte subsets, although this is not routinely performed in paediatrics. This evidence-based, co-designed document produced by Lung Foundation Australia supports improved diagnostic accuracy, safe bronchoscopy procedures and informed clinical decision-making for children with diffuse parenchymal lung diseases. It is a vital guide for clinicians seeking to apply evidence-based protocols for respiratory sampling in chILD and strengthen outcomes through multidisciplinary collaboration and early detection.