Which investigations should be prioritized in a patient suspected of having bronchiectasis?

In a patient suspected of having bronchiectasis, the following investigations should be prioritized:

• Sputum culture to identify colonizing pathogens and guide antibiotic treatment ¹.
• Chest X-ray as a baseline to exclude other pathology and help confirm diagnosis in severe disease, although it has limited sensitivity and specificity ¹.
• High-resolution computed tomography (HRCT) thorax is the most important imaging test to establish the diagnosis of bronchiectasis ¹.
• Spirometry to assess airflow obstruction severity and identify coexisting diagnoses such as COPD ¹.
• Oxygen saturation measurement to assess oxygenation status ¹.
• Full blood count including differential to evaluate for infection or inflammation ¹.
• Assessment for underlying causes including testing for cystic fibrosis (sweat chloride or gene testing), serum immunoglobulins (IgG, IgA, IgM) for antibody deficiency, serum total IgE and specific IgE or skin prick test for Aspergillus to exclude allergic bronchopulmonary aspergillosis, and specific antibody levels against Streptococcus pneumoniae ¹.

Additional investigations may be guided by clinical features, such as tests for primary ciliary dyskinesia, rheumatoid factor, anti-CCP, ANCA, HIV serology, alpha-1 antitrypsin deficiency, and gastrointestinal investigations ¹.

Referral to a respiratory consultant is recommended for confirmation of diagnosis, further investigations, and management ¹.