COPD: Causes, Stages, and Treatments

APRIL 23, 2018
Kathleen Kenny, PharmD, RPh
Chronic obstructive pulmonary disease (COPD) is a broad term used to include chronic bronchitis, emphysema, or a combination of both. It is a slowly progressive disease characterized by difficulty emptying air out of the lungs.1 COPD is a major component of chronic lower respiratory disease, which is the third-leading cause of death in the United States.2 

Chronic bronchitis is a condition that causes the airways to swell and produce more sputum. As the airways become increasingly narrow, expelling breath becomes more difficult.3

Emphysema damages the alveoli of the lungs, causing them to lose elasticity. Air becomes trapped in the alveoli, causing hyperinflation. Without the support of the alveoli, airways collapse, causing obstruction.3 The damage done by COPD is permanent.

Staging
According to the Global Initiative for Chronic Obstructive Lung Disease program, the stages of COPD are based on the forced expiratory volume in 1 second (FEV1) of a standard predicted value as follows: Stage I is FEV1 of equal to or more than 80% of the predicted value; stage II is FEV1 of 50% to 79% of the predicted value; stage III is FEV1 of 30% to 49% of the predicted value; and stage IV, also known as end-stage COPD, is FEV1 of less than 30% of the predicted value or FEV1 of less than 50% of the predicted value plus respiratory failure.3

Risk Factors
In most cases, long-term cigarette smoking is the cause of the lung damage that leads to COPD. This risk is directly proportional to the packs smoked per day and years of smoking. Other smoked tobacco products, including cigars, marijuana, and pipes, also increase the risk of COPD. Additional factors are likely to contribute to the development of COPD, as only about 20% to 30% of smokers develop the disease.4 This risk increases even more in patients who have asthma or smoke.4

Long-term exposure to chemical dust, fumes, and vapors can irritate the lungs and cause inflammation.4 In developing-world countries, COPD often occurs after exposure to burning fuel for cooking or heating in rooms without proper ventilation.4

An alpha-1-antitrypsin (AAt) deficiency can increase the risk of developing COPD. This protein is produced by the liver and secreted into the bloodstream, eventually making its way to the lungs, where it acts as a lung protectant. An AAt deficiency can damage the lungs in infants and children, whereas typical COPD is usually diagnosed in patients over 40 years old.4

Treatment
The 3 major goals of treatment are to decrease respiratory symptoms and improve quality of life, lessen airflow limitation, and prevent and treat secondary complications such as hypoxemia and infections.3

Lifestyle changes are essential to treating COPD. Patients who smoke or are regularly exposed to secondhand smoke must stop. There are many smoking cessation programs and products available to help people make this change. This is, by far, the best thing they can do to improve their outcomes.1

Avoiding places with dust, fumes, and other lung irritants that may be inhaled will also help.

In addition, it is important to maintain adequate nutrition. Shortness of breath and fatigue often make eating difficult, but proper nutrition is essential to lowering the risk of infections and reducing symptoms.1

Bronchodilators are used to relax the muscles around the airways. Open airways make breathing much easier. Depending on the severity of COPD, short-acting bronchodilators, long-acting bronchodilators, or a combination of both can be used.5 Bronchodilators can be administered through an inhaler or a nebulizer.

Short-acting bronchodilators work quickly and last for 4 to 6 hours. These are used on an as-needed basis as a rescue. Long-acting bronchodilators work more slowly but last for 12 to 24 hours. Long-acting bronchodilators are used daily as a maintenance medication.5 Short-acting and long-acting bronchodilators include anticholinergics and beta2-agonists.5

Beta2-agonists are potent drugs that relax the airway muscles, opening airways. Anticholinergic agents prevent airway muscles from constricting, thereby keeping airways open and allowing mucus to clear from the lungs more easily.

Anti-inflammatories can be used to treat COPD as well. These decrease mucus production and swelling. Corticosteroids are the most common anti-inflammatory used in COPD. These steroids are usually administered through an inhaler, but there are pills available for short-term treatment of COPD flare-ups.

Cardiopulmonary rehabilitation helps improve the well-being of patients with COPD. This is a team approach and may include dietitians, doctors, exercise specialists, nurses, physical therapists, and respiratory therapists. The goal of cardiopulmonary rehabilitation is to bring disease management training, an exercise program, and nutritional and psychological counseling together to promote positive health outcomes.1

Oxygen therapy is often used in severe COPD. Low levels of oxygen in the blood can cause a poor quality of life. Oxygen can be used all the time or just at certain times during the day.

As a last resort, surgery may benefit patients with COPD. Those with emphysema-related COPD may benefit from bullectomy and lung volume reduction surgeries. Patients with severe COPD may be candidates for lung transplantation.1

The stage of COPD often dictates the required therapy. Stage I COPD usually requires only a short-acting bronchodilator. Patients with stage II COPD would benefit from cardiopulmonary rehabilitation and both long- and short-acting bronchodilators. Stage III COPD treatment includes cardiopulmonary rehabilitation, an inhaled steroid for repeated exacerbations, and both long- and short-acting bronchodilators. Stage IV COPD requires inhaled steroids, both long- and short-acting bronchodilators, long-term oxygen therapy, and possible lung volume reduction surgery or lung transplantation.3

An important thing to keep in mind for patients with COPD is to make sure that they are vaccinated against the illnesses that attack the lungs, such as influenza and pneumonia. Patients with COPD are more susceptible to lung infections, and these infections will exacerbate their conditions.
 
Kathleen Kenny, PharmD, RPh, earned her PharmD from the University of Colorado Health Sciences Center in Aurora. She has more than 25 years of experience as a community pharmacist and is a freelance clinical medical writer based in Colorado Springs, Colorado.

References
  1. COPD. National Heart, Lung, and Blood Institute website. www.nhlbi.nih.gov/print/4972. Accessed February 9, 2018.
  2. Centers for Disease Control and Prevention. COPD-related mortality by sex and race among adults aged 25 and over: United States, 2000-2014. cdc.gov/mmwr/preview/mmwrhtml/ss5106a1.htm. Published September 8, 2016. Accessed February 25, 2018.
  3. Davis CP. COPD (chronic obstructive pulmonary disease) symptoms, causes, stages and life expectancy. Medicine.net website. medicinenet.com/copd_chronic_obstructive_pulmonary_disease/article.htm. Accessed February 9, 2018.
  4. COPD. Mayo Clinic website. mayoclinic.org/diseases-conditions/copd/symptoms-causes/syc-20353679?p=1. Accessed February 9, 2018.
  5. Managing your COPD medications. American Lung Association website. lung.org/lung-health-and-diseases/lung-disease-lookup/copd/diagnosing-and-treating/managing-your-copd-medications.html. Updated December 16, 2017. Accessed February 9, 2018.


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