Assessment of Ventilation-perfusion Abnormalities in Patients With Stable Smoking-related Airways Disease

Assessment of Ventilation-perfusion Abnormalities in Patients With Smoking-related Airways Disease in Stable Condition and the Effect of Bronchodilator Therapy

Subjects undergo history, examination, lung function assessment after informed consent has been obtained. All subjects will undergo ventilation-perfusion scans. If there first scan is normal they will undergo a second and final scan four weeks later. If abnormal they will undergo two further scans with either nebulized bronchodilator or nebulized saline prior to their second and third scans. Each time they will have repeat lung function tests prior to scanning. We will examine the regional changes in ventilation and perfusion and there relationship to lung function.

As in Brief description

Inclusion Criteria:

• FEV1 < 70% predicted at baseline on spirometry
• significant smoking history or alpha 1 antitrypsin deficiency
• no evidence of current infection or restrictive lung disease

Exclusion Criteria:

• history of other significant respiratory disease
• significant respiratory infection within 6 weeks
• history of significant physical or mental illness rendering them unfit for the study in the opinion of the investigator
• taken part in any other research within the past 12 months, or received exposure to ionizing radiation