Chronic Obstructive Pulmonary Disease
Chronic Obstructive Pulmonary Disease (COPD) is a condition where the airways in the lungs become narrowed and damaged. The 2 ends of the spectrum of disease are Chronic Bronchitis and Emphysema, but most patients have symptoms and pathology that falls somewhere in-between. As the lungs get more damaged over time, it gets increasingly difficult to breathe, and in severe cases, it affects the ability to get enough oxygen into the bloodstream and clear out the carbon-dioxide.
Chronic Bronchitis – describes patients who have a chronic cough with sputum. The airflow is reduced due to damage of the airways.
Emphysema – describes damage to the air sacs (alveoli). Shortness of Breath (rather than cough with phlegm) is the main feature.
What Causes COPD?
Cigarette smoking (including passive exposure) is the most common cause. About 80% of COPD is due to smoking. Exposure to particulate matter, dusts, gases, fumes, etc may also be a risk factor. There is also evidence for genetic predisposition, allergy, and certain infections.
Symptoms
Symptoms are different in those with Emphysema and Chronic Bronchitis. The most common symptoms are cough with phlegm and shortness of breath. Symptoms are minimal in early disease and gets worse as disease progresses. Others symptoms are wheezing, fatigue and morning headaches.
Symptoms are not entirely dependent on the severity of COPD – patients with severe COPD can have a good functional state, and vice-versa. Other factors that influence the level of functioning are heart function and level of strength and conditioning. Treatment can help with most symptoms. In most patients, the oxygen levels are normal, and the shortness of breath is due to damage to the lungs causing ‘air-trapping’ and ‘hyper-inflation’ of the lungs rather than low oxygen levels. Inhalers help ‘deflate ‘ the lungs, amongst other benefits.
Diagnosis
The ‘gold standard’ for diagnosis of COPD is measuring respiratory function. This is done by measuring spirometry, lung volumes and diffusion capacity.
Spirometry involves taking a deep breath, followed by breathing out forcefully and fully. It measures how much air and how fast one can blow out. Lung volumes can be measured in various ways. One of the commonest ways is using a ‘body box’, which looks similar to a phone booth. These tests are also used to assess response to treatment and progression of disease.
Chest X-Ray is often normal, even in severe disease, and is not useful in making a diagnosis.
CT scan of the chest gives far more detail than a Chest X-Ray, however, is not routinely required in every patient.
Treatment
By far, the most important aspect of managing COPD is stopping smoking. Stopping smoking, no matter how late, slows progression of COPD. The role of inhalers is discussed below. Other aspects of treatment are:
- Keeping active, and having a regular exercise plan. Participating in a Pulmonary Rehabilitation program can be very useful.
- Ensuring vaccinations are kept up to date.
- Treating infections early and aggressively.
- Home oxygen may benefit patients with persistently low oxygen levels.
- Treating other health conditions such as heart disease, obesity etc. which contribute to breathlessness.
Medications
There are various categories of medications that are useful in COPD. These include:
- Anticholinergics – (eg. Ipratropium, Tiotropium and Glycopyronium)
- Inhaled steroids (eg. Budesonide, Fluticasone and Ciclesonide)
- Bronchodilators – include short acting (eg Salbutamol) and long acting (Salmeterol, Eformeterol and Indacaterol)
The choice of medications depend on various factors. Some patients may benefit from an inhaler from each of the above categories, but patients with milder forms of COPD may not need any regular inhalers.
