COPD

Question 1

What are 2 details about chronic obstructive pulmonary disease (COPD)?

Answer 1

Chronic Obstructive Pulmonary Disease (COPD) actually refers to the presence of either of two conditions, emphysema or chronic bronchitis, which may exist simultaneously or separately in a given
individual

The diagnosis of COPD is initially suggested by chronic repeated episodes of dyspnea (shortness of
breath), wheezing and coughing with or without mucous production

Question 2

What are 11 details about the diagnosis of COPD?

Answer 2

In emphysema uncompromised by chronic bronchitis, the patient is typically barrel-chested and dyspneic
with obviously prolonged expiration due to air trapping in the lungs

Significant weight loss is a common presenting symptom. Such patients remain well oxygenated and
are thus referred to as “pink puffers”

Pathologically, the lungs are characterized by permanent enlargement of the air spaces distal to the terminal bronchioles accompanied by significant destruction of the alveolar walls

Chronic bronchitis is clinically defined as persistent cough with sputum production for at least three months in at least two consecutive years

This condition in its pure form involves chronic bacterial or viral infection and inflammation of the lungs

Patients characteristically are obese and may be cyanotic and hypercapnic due to lack of oxygen and excess carbon dioxide in the blood, respectively

Due to the bluish tinge of skin and lips from cyanosis and fluid retention from congestive right heart failure (cor
pulmonale), such patients are referred to as “blue bloaters”

The diagnosis of COPD is confirmed using spirometry, a test that measures the ratio of the forced expiratory volume of air in one second by the patient (FEV1) to the forced vital capacity of the lungs (FVC)

Ratios less than 0.70 are diagnostic of COPD

Radiographic images of the lungs may aid in the diagnosis and biopsy specimens are sometimes ascertained to microscopically assess the degree of alveolar destruction in emphysema

Emphysema and chronic bronchitis are often superimposed in the same patient

The coexistence of both conditions in the same individual is the rule rather than the exception

Question 3

What are 4 details about the stages of COPD?

Answer 3

The stages of COPD are based upon post-spirometry values measured after administration of a bronchodilator (beta 2 agonist)

Chronic bronchitis is diagnosed according to clinical parameters (productive cough for three months in two consecutive years)

Chronic bronchitis is easier to diagnose than emphysema giving rise to higher prevalence rates

Pathologic studies of biopsy specimens from COPD patients with Stage III or Stage IV disease invariably reflect the presence of components of both emphysema and chronic bronchitis

Question 4

What are 3 details about the age distribution of COPD?

Answer 4

The onset of COPD (chronic bronchitis and/or emphysema) increases exponentially with age in both men and women

After age 55 years, the prevalence in men is approximately double that in women (12% of men over 75 years have COPD compared to 6% in women)

This marked gender difference primarily reflects the greater rates of smoking among men

Question 5

What are 5 details about the global burden of COPD?

Answer 5

Chronic Obstructive Pulmonary Disease (COPD) causes more than 3 million deaths annually in the world
population

Overall, COPD ranks fifth in cause-specific mortality and is projected to climb even higher in the coming years

The vast majority of deaths from COPD (nearly 90%) occur in developing countries

In developed countries, COPD currently ranks third in mortality, behind only cardiovascular disease and cancer

Approximately 175 million people worldwide suffer from symptomatic COPD

Question 6

What are 4 details about the pathogenesis of COPD?

Answer 6

Chronic Obstructive Pulmonary Disease (COPD) is initiated by inflammation, usually due to chronic exposure of the airways to tobacco smoke

Inflammation triggers chemotaxis and infiltration of the bronchioles and alveoli by macrophages and neutrophils

Invading cells of the innate immune system secrete cytokines and degradative enzymes such as collagenase, elastase and matrix metalloproteinases that in turn biodegrade elastin, collagen and other proteins leading to the loss of alveolar wall integrity and enlargement of the alveolar air spaces

These features are the pathological hallmarks of emphysema

Question 7

What are 6 details about tobacco use and COPD (BOLD initiative)?

Answer 7

The international Burden of Obstructive Lung Disease (BOLD) initiative was developed to estimate the worldwide prevalence of COPD and its risk factors using standardized methods

Based on results from 12 participating centers, the smoking-related risk of COPD increased by 28% in women and 16% in men for each 10-pack-year increment of smoking

Results from BOLD and other studies indicate that 50% of chronic smokers eventually develop COPD

Incident COPD cases were also detected among male and especially female never-smokers, indicating that other environmental exposures such as passive smoking, occupational exposures, and outdoor and indoor air pollution contribute significantly to the development of COPD

The predominant etiologic agent in the genesis of both emphysema and chronic bronchitis is cigarette smoking (or any other form of smoking tobacco)

Nevertheless, there is substantial international variation in death rates possibly reflecting smoking behavior, type and processing of tobacco, pollution, climate, respiratory management, and genetic factors

Question 8

What are 5 details about tobacco use and COPD (Rotterdam study)?

Answer 8

The Rotterdam Study was designed to examine the incidence of COPD and the risk associated with aging and smoking in a prospective cohort of men and women in the Netherlands

In the study cohort, 7,983 participants aged 55 years or older at baseline were followed on average for 11 years

The incidence of COPD for the entire cohort was 9.2 cases per 1,000 person-years

Crude incidence rates were higher in men than women (14.4 versus 6.2 per 1,000 person-years) and higher in smokers than never-smokers (12.8 versus 3.9 per 1,000 person-years)

Ten pack-years of smoking increased the risk nearly 4-fold and 50 pack-years of smoking increased the risk nearly 9-fold

Question 9

What are 2 details about air pollution and COPD?

Answer 9

As opposed to studies of high risk groups such as miners who are exposed to inordinately high levels of
occupational dust, investigations of the health effects of air pollution in the general population are more complex due to difficulties in obtaining accurate
measures of exposure to relatively low levels of contamination over long periods of time

Though some evidence is emerging from epidemiologic investigations linking exposure to motor vehicle exhaust near high volume traffic roads with adverse health effects including COPD, novel experimental designs are
necessary to accrue definitive evidence of causal effects

Question 10

What are 3 details about environmental tobacco smoke and COPD?

Answer 10

Several epidemiologic studies have examined the risk of developing COPD in individuals exposed to environmental tobacco smoke (ETS)

Combined results suggest there is a significant dose response in COPD risk with increasing duration of ETS exposure

The biological effects of ETS are similar to mainstream smoke and individuals with chronic heavy exposure should be considered at increased risk for the development of COPD

Question 11

What are 3 details about indoor air pollution and COPD?

Answer 11

Recent estimates from the World Health Organization suggest that nearly 3 billion people, almost half of the
world population, are continually exposed to biomass smoke from the combustion of solid fuels such as
wood and coal (WHO, 2006)

In many regions of Africa, Central America and Asia, the vast majority of rural homes use solid fuel as the
primary cooking and heating fuel

Because of their routine cooking and other domestic activities, women in these households tend to have far greater exposure to indoor air pollution than men

Question 12

What are 6 details about air pollution and COPD (pneumoconiosis)?

Answer 12

Numerous studies have shown that air contaminants that are present in the atmospheric environment of the
industrialized world are capable of provoking lung dysfunction and respiratory ailments including COPD

Repeated inhalation of coal dust or other carbon particles leads to the deposition of these materials
throughout the respiratory bronchioles and alveolar spaces producing carbon pigmentation of the lungs known as pulmonary anthracosis

Many other small particles that enter the airways, both organic and inorganic, can also lead to the development of pneumoconiosis

The etiologic role of coal mine dust in the pathogenesis of debilitating pneumoconiosis and Black Lung Disease is a well known phenomenon

Silicosis is a particularly severe form of pneumoconiosis resulting from the inhalation of silica dust

Pneumoconiosis is characterized by the accumulation of such particles within the macrophages of the lungs
accompanied by irritation, inflammation and the release of destructive enzymes and reactive oxygen species that result in cell necrosis and, subsequently, pulmonary fibrosis

Question 13

What are 4 details about the primary prevention of COPD?

Answer 13

As with all smoking-related diseases, the key to primary prevention is complete abstinence from tobacco use.

Educational efforts must be initiated early in life to prevent young individuals from taking up the smoking habit

Smoking cessation is the single most important behavioral change to prevent COPD or reduce its
progression

Intensive intervention involving counseling, pharmacotherapy, or both is usually required to successfully motivate an individual to quit smoking

Question 14

What are 4 details about a1 antitrypsin deficiency and COPD?

Answer 14

The best documented genetic risk factor for COPD is α1 antitrypsin deficiency, a relatively rare condition that is present in only 1-2% of patients with mild to moderate COPD

Nevertheless, up to 50% of patients over 40 years of age with severe (Stage IV) COPD have been found to have α1 antitrypsin deficiency

The glycoprotein, α1 antitrypsin, is responsible for inhibiting collagenase, elastase and other proteases derived from leukocytes, particularly in the alveoli of the lungs

If α1 antitrypsin is deficient or absent, there is uncontrolled degradation of alveolar proteins such as elastase and collagen resulting in the accelerated development of emphysema

Question 15

What are 3 details about lung cancer and COPD?

Answer 15

The dominant risk factor for both lung cancer and COPD is chronic tobacco smoking

The impaired lung function of COPD patients increases their lung cancer risk

The relative risk of lung cancer is significantly increased in patients with COPD and more severe disease accentuates the risk

Question 16

What are 6 details about the control of air pollution?

Answer 16

Chronic exposure to high concentrations of indoor or outdoor air pollution increases the risk of developing COPD

Outdoor pollution is mainly due to the combustion of fossil fuel for heating, industry and transport. In particular, motor vehicle exhaust is a primary
source

Indoor pollution arises from the combustion of biomass for cooking and heating

In many nations, outdoor pollution has been greatly reduced by switching from coal to cleaner burning fuels such as oil and gas and by the elimination of
poorly controlled incinerators

Emission of toxic chemicals in motor vehicle exhaust has been reduced through the use of catalytic converters and air injection systems and development of more efficient engines

Indoor pollution can be eliminated and controlled by ventilation, removal of the source of pollution, improved cooking and heating devices and behavioral adjustments to avoid exposure