Table 1 The exclusion criteria used for safety reasons prior to performing sputum induction

• FEV₁ < 60 %/< 1.0 L (post – Salbutamol 200 micrograms)

• SaO₂ < 90 % on room air

• Unable to take salbutamol

• Extreme shortness of breath

• Acute Respiratory Distress Syndrome

• Known haemoptysis

• Known arrhythmias/angina

• Known thoracic, abdominal or cerebral aneurysms

• Recent pneumothorax

• Pulmonary emboli

• Fractured ribs/recent chest trauma

• Recent eye surgery

• Known pleural effusions

• Pulmonary oedema