Chronic obstructive pulmonary disease (COPD)

DEFINITION: A progressive, irreversible disease of the lungs that causes airflow obstruction and a progressive decline in lung function. The most common form of COPD is a combination of chronic bronchitis and emphysema.

ANATOMY OR SYSTEM AFFECTED: Lungs, respiratory system

CAUSES:Chronic abnormal inflammatory response of the lungs to noxious particles or gases resulting in small airway disease and parenchymal (tissue) destruction

SYMPTOMS: Chronic cough, shortness of breath, wheezing, chest tightness; limited physical activity

DURATION: Chronic and progressive

TREATMENTS: None; alleviation of symptoms (bronchodilators, antibiotics, steroids, oxygen therapy, vaccination against pneumonia and influenza, smoking cessation, pulmonary rehabilitation)

Causes and Symptoms

Patients experiencing chronic obstructive pulmonary disease (COPD), a combination of chronic bronchitis and emphysema, have a chronic cough and shortness of breath that progressively limits their tolerance for physical activity. A physical examination may appear normal in the early stages of COPD, but as the disease progresses, tachypnea and wheezing occur. Over time, the occasional cough becomes more frequent, and greater effort is exerted to breathe. In later stages of COPD, the circulatory system may be affected because the lungs can no longer supply an adequate amount of oxygen to the body. Other signs of advanced COPD are a barrel chest, pursed lip breathing, and a prolonged expiratory phase of respirations. Coughing produces phlegm that becomes increasingly difficult to expel as it thickens. Persons with advanced COPD cannot lie flat to sleep and may need to sit in a semi-upright position in order to breathe.

The major risk factor for COPD is cigarette smoking. Other risk factors are air pollution (including exposure to mining), occupational exposures (such as organic and inorganic dusts, chemical agents, and fumes), a history of childhood respiratory infections, and active asthma. In chronic bronchitis, the lining of the bronchial tubes become irritated, inflamed, and filled with mucus that blocks the airways, making it difficult to breathe. In emphysema, the alveoli become irritated, stiffen, and cannot transfer oxygen and carbon dioxide in the blood. Thus far, a deficiency of the enzyme alpha-1 antitrypsin is the best documented genetic cause of COPD.

COPD is a progressive disease that presents few symptoms until it is well developed in the lungs. It is usually not identified until the patient is fifty to sixty years old, although COPD caused by a deficiency of alpha-1 antitrypsin may be identified by thirty to forty years of age.

Confirmation of the diagnosis of COPD is made by pulmonary function tests (PFTs). PFTs are helpful in diagnosing COPD in its early stages and may be helpful in convincing patients to consider smoking cessation, if necessary, to slow the progression of COPD. Spirometry measures the amount of air exhaled in one second, or forced expiratory volume (FEV1). The total amount of air exhaled, or forced vital capacity (FVC), is compared to the FEV1 to determine the extent of airway obstruction. A peak flow meter can show the severity of breathing impairment; after a deep breath, the patient blows into the instrument as forcefully and for as long as possible. Arterial blood gas tests measure the level of oxygen and carbon dioxide in the blood. Serum alpha-1-antitrypsin levels are measured by blood samples. Finally, chest X-rays, pulmonary ventilation-perfusion scans, and chest magnetic resonance imaging (MRI) scans may all help to identify the degree of lung damage caused by COPD, including bronchial wall thickening, ill-defined opacities in the parenchyma, and prominent vessels.

Treatment and Therapy

Because no cure exists for COPD, treatment focuses on decreasing symptoms and reducing complications. Bronchodilator medications, antibiotics, corticosteroids, oxygen therapy, and vaccination against pneumonia and influenza are used to treat or prevent symptoms, slow the progression of the disease, and manage any complications. In addition to corticosteroids, medications for the management of COPD include short-acting inhaled anticholinergics, short-acting inhaled beta-2 agonists (SABA), and long-acting beta-2 agonists (LABA). Smoking cessation is vitally important for slowing the progress of COPD. Nicotine replacement therapy, antidepressants such as bupropion, and counseling are some of the methods used to assist in smoking cessation.

Patients with COPD who are hypoxic may require long-term oxygen therapy to improve their functional status and rate of survival. The purpose of oxygen therapy is to maintain adequate oxygen levels to prevent respiratory difficulties.

Pulmonary rehabilitation can help reduce hospitalizations and increase the quality of life for those with COPD, improving their overall functional status. Pulmonary rehabilitation includes therapies to enhance breathing, exercise training to improve muscle strength and stamina, and self-management education and nutrition counseling. Pursed lip breathing helps to relieve abnormal breathing (dyspnea) and to slow respirations.

Lung transplantation and lung volume reduction surgery (LVRS) may be options for people who are affected by very severe emphysema. Lung volume reduction surgery involves the partial removal of the most damaged areas of the lungs in order to allow for better lung expansion of the normal areas of the lung. Gene therapy and alpha-1-antitrypsin augmentation therapy were evaluated as treatments for alpha-1-antitrypsin deficiency. The American Thoracic Society and the European Respiratory Society recommend IV alpha-1-antitrypsin augmentation therapy for alpha-1-antitrypsin deficiency in patients with airflow obstruction or with acute rejection or infection following lung transplant.

Perspective and Prospects

The primary cause of COPD is tobacco smoke—either through smoking or exposure to secondhand smoke. According to the American Lung Association, COPD is the sixth leading cause of death in the United States, following heart disease and cancer. The American Lung Association estimates that 11.7 million American adults experience COPD, chronic bronchitis, or emphysema. The prevalence was greater among Non-Hispanic White people, women, and those aged sixty-five and over.

According to the World Health Organization (WHO), COPD is the third leading cause of death worldwide. Those with COPD are prone to recurrent respiratory infections, and their quality of life gradually declines as the disease worsens. Smoking cessation is the single most important prevention method. Exposure to indoor air pollution, particularly from the use of biomass fuels for cooking and heating, is the leading risk factor for COPD in low-income countries.

Bibliography

Alvar, Agusti. "Global Initiative for Chronic Obstructive Lung Disease 2023 Report: Gold Executive Summary." European Respiratory Journal, vol. 61, no. 4, 3 Apr. 2023, doi.org/10.1183%2F13993003.00239-2023. Accessed 28 Mar. 2024.

American Lung Association. Trends in COPD (Chronic Bronchitis and Emphysema): Morbidity and Mortality. New York: American Lung Assoc., 2013. PDF file.

Barnes, Peter J., ed. Chronic Obstructive Pulmonary Disease. Philadelphia: Elsevier, 2014. Print.

Barnett, Margaret. Chronic Obstructive Pulmonary Disease in Primary Care. New York: Wiley, 2006. Print.

Calverley, Peter M. A., et al., eds. Chronic Obstructive Pulmonary Disease. 2nd ed. London: Hodder Arnold, 2003. Print.

"Chronic Obstructive Pulmonary Disease (COPD)." World Health Organization (WHO), 16 Mar. 2023, www.who.int/news-room/fact-sheets/detail/chronic-obstructive-pulmonary-disease-(copd). Accessed 9 Oct. 2024.

"COPD Trends Brief: Prevalence." American Lung Association, www.lung.org/research/trends-in-lung-disease/copd-trends-brief/copd-prevalence. Accessed 9 Oct. 2024.

Haas, François, and Sheila Sperber Haas. The Chronic Bronchitis and Emphysema Handbook. Rev. ed. New York: Wiley, 2000. Print.

Jenkins, Mark. Chronic Obstructive Pulmonary Disease: Practical, Medical, and Spiritual Guidelines for Daily Living with Emphysema, Chronic Bronchitis, and Combination Diagnosis. Center City: Hazelden, 1999. Print.

Kaufman, Gerri. "Chronic Obstructive Pulmonary Disease: Diagnosis and Management." Nursing Standard 27.21 (2013): 53–62. Print.

Kind, Jared, ed. Chronic Obstructive Pulmonary Disease (COPD): Clinical Symptoms, Emerging Treatment Strategies and Impact on Quality of Life. New York: Nova Biomedical, 2016. Print.

Parker, James N., and Philip M. Parker, eds. The 2002 Official Patient’s Sourcebook on Chronic Obstructive Pulmonary Disease. San Diego: Icon Health, 2002. Print.

Rennard, Stephen I., and Bartolome R. Celli, eds. Chronic Obstructive Pulmonary Disease. Philadelphia: Saunders, 2012. Print.

"What Is COPD?" National Heart, Lung, and Blood Institute. Natl. Inst. of Health, 31 July 2013. Web. 9 Sept. 2014.

Zirimis, Leonidas, and Adelino Papazoglakis, eds. Chronic Obstructive Pulmonary Disease: New Research. New York: Nova Biomedical, 2012. Print.