Chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease is a growing public health problem that is expected to worsen with an aging population and increased use of tobacco products worldwide. Smoking cessation is the only effective prevention. Employers are in a unique position to help employees quit smoking. During the long asymptomatic phase, lung function continues to decline; as a result, many patients seek medical attention only at an advanced stage or after an acute exacerbation. To maintain patients’ quality of life and reduce healthcare costs associated with this chronic disease, physicians must accurately diagnose the condition and appropriately treat patients throughout the long course of the disease. This article describes the current approach to patient management.
(COPD) is a poorly reversible lung disease that is a leading cause of morbidity and mortality worldwide. In the United States, it is the fourth leading cause of death after heart disease, cancer, and cerebrovascular disease. By 2020, it is projected to become the third leading cause of death worldwide. Unlike other major chronic diseases in the United States, the prevalence and mortality of COPD are similar further increased; mortality rates doubled between 1970 and 2002, and for the first time in 2000, female mortality exceeded male mortality. In the United States, 12 million patients are currently diagnosed with COPD, but it is believed that this is not the case at least, so is the case for as many people with impaired lung function suggestive of COPD who were undiagnosed.
The American Thoracic Society defines COPD in terms of chronic bronchitis and emphysema. Chronic bronchitis is characterized by the clinical symptoms of excessive cough and sputum production; Emphysema refers to chronic dyspnea resulting from enlarged air spaces and destruction of lung tissue. The GOLD Initiative defines COPD as “a disease state characterized by airflow limitation that is not fully reversible. Asthma is also characterized by airflow obstruction and inflammation, but also involves airway hypersensitivity to stimuli; therefore, it distinguishes the reversibility of functional deficits in asthma from COPD.
Cigarette smoking is the main risk factor for COPD. However, approximately 1 in 6 Americans with COPD has never smoked. Occupational and environmental exposures to chemical fumes, dusts, and other lung irritants account for 10% to 20% of cases. Individuals with a history of severe childhood lung infections are more likely to develop them of COPD.
COPD is a slowly progressive disease with a long asymptomatic phase during which lung function continues to decline. Persistent cough, especially with mucus production, is a common symptom. Dyspnea, particularly on exertion, wheezing and chest tightness may also be present. As the disease progresses, exacerbations may become more frequent and life-threatening complications may occur. End-stage COPD is characterized by severe airflow limitation, severe disability, and systemic complications. Patients often succumb to respiratory failure or pulmonary infection. Extra pulmonary effects associated with COPD include weight loss, nutritional abnormalities and muscle atrophy. Different COPD phenotypes with specific prognostic implications have been identified.
Cigarette smoking or exposure to harmful substances induces an inflammatory process in the lungs and airways of the bronchial tree, resulting in small airway disease and parenchymal destruction.
The loss of elasticity of the alveolar attachments or their destruction is a hallmark of emphysema.
The net result of the pathophysiological processes of COPD is increased resistance to airflow and decreased expiratory flow rate. Removing the inflammatory stimulus (e.g. quitting smoking)
Early detection and assessment of symptoms allows for earlier treatment to preserve lung function and slow disease progression. Diagnosis is primarily clinical and most patients are diagnosed by primary care physicians. Suggestive symptoms are chronic cough, excessive sputum production and dyspnea, particularly when any of these symptoms are associated with a history of cigarette smoking or regular exposure to pollutants or toxins in the workplace or environment. Special attention is required to identify patients with these findings and to consider further evaluation earlier than in the past.
Screening for smoking, cough, sputum production, dyspnea and history of exposure should be a routine part of reviewing systems and if present, suggest the need for further evaluation. However, the evidence does not support the use of spirometry for screening purposes in adults who do not have respiratory symptoms.
Staging of COPD
Asthma should be excluded in the differential diagnosis. Unlike COPD, asthma generally occurs early in life and its symptoms vary from day to day, tending to worsen at night or early in the morning. Asthma is often associated with allergy, rhinitis or eczema and tends to have a family history. The degree of reversibility of airway restriction also distinguishes the two conditions.
Treatment of COPD
The most important measure to change the course of COPD in smokers is smoking cessation. The Lung Health Study reported a progressive decrease in FEV1 after bronchodilation in men and women who continued to smoke over an 11-year period.
A number of medications are effective in promoting smoking cessation, including nicotine replacement products (e.g., nicotine gum, patch and inhaler), the antidepressant bupropion (Zyban) and the drug varenicline (Chantix), in addition to counselling. Most smokers should be treated with varenicline as the drug of first choice.
The 3 FDA approved HFA albuterol inhalers are ProAir, Proventil and Ventolin. The fourth HFA inhaler, Xopenex, contains the active ingredient levalbuterol.
The multidimensional BODE index was developed to assess an individual patient’s risk of dying from COPD.
Body Mass Index
Lung transplantation to improve quality of life and lung function is sometimes done in appropriately selected patients with very advanced COPD. The potential benefits of surgery in patients with COPD must be weighed against the risks, including postoperative complications such as lung infections and increased airway obstruction.
COPD will remain a significant health problem for years to come. Early detection of the disease through primary care screening for the most common symptoms in smokers or those exposed to air pollutants or toxins will lead to earlier diagnosis and treatment. Focusing on smoking cessation will have a major impact on disease progression.