Mansoor, 67, is height 165 cm and has been a smoker for 50 years.

He has a history of increasing shortness of breath, chest infections, chronic cough, and hospital admissions (2 in the past 2 years) for respiratory failure secondary to pneumonia. His breathlessness is reproducibly related to effort. A recent chest X-ray shows significant hyperinflation.

Mansoor is referred for lung function tests to document ventilatory function and response to bronchodilator.