Despite optimal medical care with smoking cessation, pulmonary rehabilitation and medications, many people with chronic obstructive pulmonary disease (COPD) remain very breathless and limited. Some patients will have predominant emphysema with incomplete emptying of their lungs during expiration (gas trapping). In such patients, an operation called lung volume reduction surgery (LVRS) is effective and aims to remove the worst affected area of the lung. Thus, the remaining lung can function more effectively. Currently, this can be achieved using a fibre-optic camera called a bronchoscope, which have shown to be very effective in carefully selected patients.
Only a small proportion of COPD patients have the right pattern but it is still a large number of people - roughly estimated to be 15,000 eligible patients in the UK. However, despite the fact that several high quality studies on LVRS showed consistent favourable results, referral for the procedure is extremely patchy and only about 100 operations occur each year.
We will look at lung function test results to see how many patients have the appropriate pattern. This assessment is based on a new equation produced to predict benefit. The study will help to understand how to develop better treatment pathways.
The measurement of residual volume (RV) - an indicator of the degree of pulmonary gas trapping - is technically demanding and requires specific devices with additional costs. Patients with COPD who have a high enough RV are more likely to benefit from lung volume reduction surgery or another similar procedure. A model to predict RV from forced spirometry measurements (FEV1, FVC, FEV1/FVC) has been recently validated. As a national sample of current practice, we will use linked CPRD GOLD data to undertake a cohort study to provide an accurate estimate of the number of people with COPD who have a high enough RV using this novel equation. This will establish a more accurate estimate of patients who are potentially eligible for lung volume reduction procedures based on the widely available spirometry. Additionally, we will link the information about RV to whether or not these patients have been referred for pulmonary rehabilitation.
The information obtained from this study will be used to inform the development of models and strategies to improve access to this form of treatment and reduce health inequality which can then be used as a national resource.
Lung volume reduction surgery
Jennifer Quint - Chief Investigator - Imperial College London
Jennifer Quint - Corresponding Applicant - Imperial College London
Amany Elbehairy - Collaborator - Royal Brompton Hospital
Nicholas Hopkinson - Collaborator - Imperial College London
HES Admitted Patient Care;HES Outpatient;Patient Level Index of Multiple Deprivation