04 Dec The Four Stages of COPD
Chronic Obstructive Pulmonary Disorder (COPD) is a disease that blocks the movement of air in and out of the lungs. Damage to the air sacs and small passageways called bronchioles restricts the flow of air. First, the lungs produce mucous and inflammation in response to irritants like smoking and air pollution. Then, the tissue is damaged, resulting in more mucus and inflammation. This cycle is why COPD is a ‘progressive disease.’
How severe is your COPD? One way to measure lung damage is with Forced Expiratory Volume (FEV1). This is the amount of air you can exhale in one second. The increased blockage will limit the amount of air in each exhale, so your FEV is lower.
Medical providers have defined the stages using predicted value of FEV1. The ‘predicted value’ means what the value that is expected for healthy lungs, based on your age and gender.
- Stage 1 (mild): FEV1 is equal or more than 80% of predicted value
- Stage 2 (moderate): FEV1 is 50% to 79% of predicted value
- Stage 3 (severe): FEV1 is 30% to 49% of predicted value
- Stage 4 (very severe): FEV1 is less than 30% of predicted value, or less than 50% plus respiratory failure. This is ‘end-stage’ COPD. At this point, the lungs are beginning to stop working.
What medications treat COPD?
Treatments depend on the stage and symptom severity. Because the lung damage caused by COPD cannot be reversed, lifestyle changes that eliminate the irritants like smoking are the best way to slow it down. Many people also benefit from cardiopulmonary rehabilitation or surgery. But all COPD patients will take some medication to control symptoms and slow the disease:
- Long-acting bronchodilators: A “bronchodilator” is a drug that makes the air passages to expand. As a result, there is more space for air to move in and out of the lungs. Most people also have a short-acting bronchodilator (‘rescue inhaler’) for sudden attacks.
- Inhaled corticosteroids: Steroids suppress the immune system in order to reduce inflammation of the lung tissue. These are combined with a bronchodilator to ‘step up’ treatment for severe symptoms
- PDE4 inhibitors: These drugs reduce inflammation and the amount of mucus that the lungs produce. They are an ‘add-on therapy’ if other drugs cannot control symptoms.
- Supplement oxygen: Severe COPD leads to hypoxemia. This means the amount of oxygen in the blood is too low. Supplemental air is 100% oxygen, compared to the room air which is only 21% oxygen. Unfortunately, most COPD patients on oxygen therapy will stay on it long-term
What combination of drugs will I take?
Here is a rough guide to the medications used at each stage of COPD. These may differ based on your symptoms, and other medical conditions that you have.
- Stage 1: A short-acting bronchodilator (‘rescue inhaler’) whenever exacerbations or attacks occur.
- Stage 2: Rescue inhaler as needed. Take a long-acting bronchodilator daily, in addition to cardiopulmonary rehabilitation.
- Stage 3: Rescue inhaler as needed, daily long-acting bronchodilator, and inhaled glucocorticoid.
- Stage 4 (“End-Stage” COPD): All of the drugs in previous stages, plus as needed based on symptoms:
- long-term oxygen therapy
- lung volume reduction surgery
- lung transplantation.
Medications add up quickly. Some, like supplemental oxygen, can have a significant impact on your ability to conduct daily activities. Since you cannot reverse COPD lung damage, the best treatment is prevention.
Finally, if you smoke, the most important thing that you can do to slow or prevent COPD is quit.