Chronic obstructive pulmonary disease (COPD) : Introduction, Symptoms, Causes, Diagnosis, Management and Prevention - www.genericdrugscan.com

Chronic obstructive pulmonary disease (COPD) : Information

Chronic obstructive pulmonary disease (COPD) is an umbrella term used to describe chronic lung diseases that cause limitations in lung airflow. The chronic airflow limitation characteristic of COPD is caused by a mixture of small airway disease (obstructive bronchiolitis) and parenchymal destruction (emphysema), the relative contributions of which vary from person to person.

The most common symptoms of COPD are breathlessness, or a 'need for air', excessive sputum production, and a chronic cough. Daily activities, such as walking up a short flight of stairs, may become very difficult as the disease worsens.

COPD is preventable, but not curable. Treatment can slow the progress of the disease, but it worsens slowly over time. Because of this, it is most frequently diagnosed in people aged 40 years or older. Chronic bronchitis and emphysema are terms that are no longer used and are now included within the COPD diagnosis. It is not a simple smoker's cough, but an under-diagnosed, life threatening lung disease.

According to WHO estimates (2004), 65 million people have moderate to severe COPD worldwide. More than 3 million people died of COPD in 2012, which is equal to 6% of all deaths globally that year. It is known that almost 90% of COPD deaths occur in low- and middle-income countries.

In India, a study collecting data without spirometry (test to assess lung function) assessment suggested that 12 million people were affected by COPD*. Studies from the same authors show a prevalence of respiratory symptoms in 6% 7% of non-smokers and up to 14% of smokers.

At one time, COPD was more common in men, but because of increased tobacco use among women in high-income countries and the higher risk of exposure to indoor air pollution (such as biomass fuel used for cooking and heating) in low-income countries, the disease now affects men and women almost equally.

If urgent action is not taken to reduce underlying risk factors, especially tobacco use and air pollution, then total deaths from COPD are projected to increase in next twenty years. According to WHO, COPD will move from fifth leading cause of death in 2002, to fourth place in the rank projected to 2030 worldwide.

References-

www.who.int/mediacentre/factsheet

www.who.int/respiratory/copd/burde

www.who.int/respiratory/copd/en/

www.who.int/gard/publications/chronic

medind.nic.in/iae/t01/i3/iaet01i3p139g.pdf
*

medind.nic.in/iae/t06/i1/iaet06i1p23.pdf

medind.nic.in/iae/t06/i1/iaet06i1p37.pdf

COPD is a multicomponent disease with extra-pulmonary effects. The most common symptoms of COPD are:

• Breathlessness (or a "need for air"),
• Abnormal sputum (a mix of saliva and mucus in the airway),
• Chronic cough,
• Daily activities, such as walking up a short flight of stairs or carrying a suitcase, can become very difficult as the condition gradually worsens.

Stages of COPD according to Post-Bronchodilator forced expiratory volume in one second (FEV1); forced vital capacity (FVC) and symptoms:

Stage I: Mild COPD - Characterized by mild airflow limitation (FEV1/FVC < 0.70; FEV1 80% predicted). Symptoms of chronic cough and sputum production may be present, but not always. At this stage, the individual is usually unaware that his or her lung function is abnormal.

Stage II: Moderate COPD - Characterized by worsening airflow limitation (FEV1/FVC < 0.70; 50% FEV1 < 80% predicted), with shortness of breath typically developing on exertion and cough and sputum production sometimes also present. This is the stage at which patients typically seek medical attention because of chronic respiratory symptoms or an exacerbation of their disease.

Stage III: Severe COPD - Characterized by further worsening of airflow limitation (FEV1/FVC < 0.70; 30% FEV1 < 50% predicted), greater shortness of breath, reduced exercise capacity, fatigue, and repeated exacerbations that almost always have an impact on patients quality of life.

Stage IV: Very Severe COPD - Characterized by severe airflow limitation (FEV1/FVC < 0.70; FEV1 < 30% predicted or FEV1 < 50% predicted plus the presence of chronic respiratory failure*).

(*Respiratory failure is defined as an arterial partial pressure of O2 (PaO2) less than 8.0 kPa (60 mm Hg), with or without arterial partial pressure of CO2 (PaCO2) greater than 6.7 kPa (50 mm Hg) while breathing air at sea level.)

Systemic Features of COPD (extra-pulmonary effects) and co-morbidities:

• Cachexia: loss of fat free mass
• Skeletal muscle wasting
• Osteoporosis
• Depression
• Normochromic normocytic anemia
• Increased risk of cardiovascular disease
• Lung cancer
• Metabolic diseases and Diabetes mellitus

References-

www.who.int/respiratory/copd/GOLD

www.who.int/mediacentre/factsheets/

Risk factors for COPD:

(I) Genes: COPD is a polygenic disease. The genetic risk factor that is best documented is a severe hereditary deficiency of alpha-1 antitrypsin.

(II)Environmental factors:

(a)Tobacco smoke: The primary cause of COPD is tobacco smoke (including second-hand or passive exposure). Cigarette smoking is most commonly encountered risk factor for COPD. Apart from cigarettes, people from India smoke tobacco using bidis, hookahs and chillums among several other forms of smoking. Bidis are more harmful than cigarettes (although they contain only one fourth the amount of nicotine, they produce four to five times more tar than cigarettes, making one bidi as harmful as one cigarette), hookahs are more harmful than bidis and the chillum is the most harmful of the lot. Smoking during pregnancy may also pose a risk for the foetus, by affecting lung growth and development of the foetus.

Passive exposure to cigarette smoke (also known as environmental tobacco smoke or ETS) may also contribute to respiratory symptoms and COPD.

(b) Indoor air pollution: Almost 3 billion people worldwide use biomass (wood, animal dung, crop residues) and coal as their main source of energy for cooking, heating, and other household needs. In these communities, indoor air pollution is responsible for a greater fraction of COPD risk than smoking or outdoor air pollution. Biomass fuels are used by women for cooking which account for the high prevalence of COPD among nonsmoking women in parts of the Middle East, Africa and Asia. Indoor air pollution resulting from the burning of wood and other biomass fuels is estimated to kill two million women and children globally each year. The other common indoor air pollutant is the burning of mosquito coils at homes to get rid of mosquitoes. Burning one mosquito coil in the night emits as much particulate matter pollution, as that which is equivalent to around 100 cigarettes.

(c) Outdoor air pollution: Outdoor air pollution mainly from emission of pollutants from motor vehicles and industries is an important public health problem. High levels of urban air pollution are harmful to individuals with existing heart or lung disease.

(d) Occupational dusts and chemicals (such as vapours, irritants, and fumes)

(e) Lung growth and Development-Any factor that affects lung growth during gestation and childhood has the potential for increasing an individual s risk of developing COPD.

(f) Oxidative Stress (excess of oxidants and/or depletion of antioxidants are termed oxidative stress): An imbalance between oxidants and antioxidants is considered to play a role in the pathogenesis of COPD.

(g) Infections: Infections (viral and bacterial) may contribute to the pathogenesis and progression of COPD. A history of severe childhood respiratory infection has been associated with reduced lung function and increased respiratory symptoms in adulthood. Tuberculosis is recognized as a risk factor for COPD.

(h)Socioeconomic Status: There is evidence that the risk of developing COPD is inversely related to socioeconomic status. It is not clear, however, whether this pattern reflects exposures to indoor and outdoor air pollutants, crowding, poor nutrition, or other factors that are related to low socioeconomic status.

(i)Nutrition: The role of nutrition as an independent risk factor for the development of COPD is unclear. Malnutrition and weight loss can reduce respiratory muscle strength and endurance, apparently by reducing both respiratory muscle mass and the strength of the remaining muscle fibers.

(j)Asthma: Asthma may be risk factor for the development of COPD, although the evidence is not conclusive.

The causes for COPD have opposite patterns according to the geographic areas. In high- and middle-income countries tobacco smoke is the biggest risk factor, meanwhile in low-income countries exposure to indoor air pollution, such as the use of biomass fuels for cooking and heating, is the main risk factor.

References-

www.who.int/respiratory/copd/causes/en/

www.who.int/mediacentre/factsheets/f

icmr.nic.in/ijmr/2013/february/0203.pdf

www.japi.org/february_2012_special

www.japi.org/february_2012_special

Diagnosis of COPD should be considered in any patient who has symptoms of a chronic cough, sputum production, dyspnoea (difficult or labored breathing) and a history of exposure to risk factors for the disease.

COPD is confirmed by a diagnostic test called "spirometry". It measures how much air a person can inhale and exhale, and how fast air can move into and out of the lungs. Because COPD develops slowly, it is frequently diagnosed in people aged 40 or older.

The presence of a post bronchodilator FEV1/FVC < 0.70 and FEV1 < 80% predicted confirms the presence of airflow limitation that is not fully reversible. COPD may be diagnosed at any stage of the illness.

Figure-1.Spirometric Classification of Severity:

Spirometric Classification of COPD Severity based on Post-Bronchodilator FEV1

Stage I: Mild COPD

FEV1/FVC < 0.70; FEV1 80% predicted

Stage II: Moderate COPD

FEV1/FVC < 0.70; 50% FEV1 < 80% predicted

Stage III: Severe COPD

FEV1/FVC < 0.70; 30% FEV1 < 50% predicted

Stage IV: Very Severe COPD

FEV1/FVC < 0.70; FEV1 < 30% predicted or FEV1 < 50% predicted plus the presence of chronic respiratory failure*

(FEV1: forced expiratory volume in one second; FVC: forced vital capacity.)

(*Respiratory failure is defined as an arterial partial pressure of O2 (PaO2) less than 8.0 kPa (60 mm Hg), with or without arterial partial pressure of CO2 (PaCO2) greater than 6.7 kPa (50 mm Hg) while breathing air at sea level.)

Where spirometry is unavailable, clinical symptoms and signs, such as abnormal shortness of breath and increased forced expiratory time, can be used to help with the diagnosis.

A low peak flow is consistent with COPD, but may not be specific to COPD because it can be caused by other lung diseases and by poor performance during testing.

Chronic cough and sputum production often precede the development of airflow limitation by many years; although not all individuals with cough and sputum production go on to develop COPD.

References-

www.who.int/gard/publications/chronic_respiratory

www.who.int/respiratory/copd/GOLD_WR_06.pdf

www.nhlbi.nih.gov/health/health-topics/topics/co

An effective COPD management plan includes four components: (1) assess and monitor disease; (2) reduce risk factors; (3) manage stable COPD; (4) manage exacerbations.

A clinical diagnosis of COPD should be considered in any patient who has dyspnoea, chronic cough or sputum production, and /or a history of exposure to risk factors for the disease. The diagnosis should be confirmed by spirometry.

Measurement of arterial blood gas tensions should be considered in all patients with FEV1 < 40% predicted or clinical signs suggestive of respiratory failure or right heart failure.

Ongoing monitoring and assessment in COPD ensures that the goals of treatment are being met and should include evaluation of: (1) exposure to risk factors, especially tobacco smoke; (2) disease progression and development of complications; (3) pharmacotherapy and other medical treatment; (4) exacerbation history; (5) co-morbidities.

Tobacco smoke, occupational exposures, indoor and outdoor air pollution and irritants are various risk factors for COPD. Reductions of total personal exposure to these risk factors are important goals to prevent the onset and progression of COPD.

Tobacco smoke -

Health care workers should encourage all patients who smoke to quit, even those patients who come to the health care provider for unrelated reasons and do not have symptoms of COPD. Counseling delivered by physicians and other health professionals significantly increases quit rates over self-initiated strategies. Pharmacotherapy is recommended in persons when counseling is not sufficient to help patients quit smoking.

The Ministry of Health and Family Welfare, Government of India has launched National Tobacco Control Programme with the objective to bring about greater awareness about the harmful effects of tobacco use. (www.nhp.gov.in/national-tobacco-control-programme
)

With the involvement of mobile technology mCessation Programme- QUIT TOBACCO FOR LIFE is initiated to reach out and support the tobacco users of all categories who want to quit tobacco use. (www.nhp.gov.in/quit-tobacco-programme
)

Occupational exposure -The main emphasis should be on primary prevention, which is best achieved by the elimination or reduction of exposures to various substances in the workplace. Secondary prevention, achieved through surveillance and early case detection, is also of great importance.

Indoor and outdoor air pollution- Reduction of exposure to smoke from biomass fuel, particularly among women and children, is a crucial goal to reduce the prevalence of COPD worldwide. Public policy to reduce vehicle and industrial emissions to safe levels is an urgent priority to reduce the development of COPD.

The overall approach to managing stable COPD should be individualized to manage symptoms and thereby improvement in the quality of life. The approach consists of health education, medications, pulmonary rehabilitation, oxygen therapy, ventilatory support, surgical treatment.

Health education- For patients with COPD, health education can play a role in improving skills, ability to cope with illness, and health status. It is effective in accomplishing certain goals, including smoking cessation. Education also improves patient response to exacerbations.

Pharmacologic treatment- Pharmacologic therapy is used to prevent and control symptoms, reduce the frequency and severity of exacerbations, improve health status, and improve exercise tolerance.

-Bronchodilators (medications that cause widening of airway): Bronchodilator medications are central to the symptomatic management of COPD. They are given on an as-needed basis or on a regular basis to prevent or reduce symptoms.

The principal bronchodilator treatments are Beta2-agonists, anticholinergics, theophylline, and a combination of one or more of these drugs. Regular treatment with long-acting bronchodilators is more effective and convenient than treatment with short-acting bronchodilators.

-Glucocorticosteroids:

The role of Glucocorticosteroids in the management of stable COPD is limited to specific indications. Regular treatment with inhaled glucocorticosteroids should only be prescribed for symptomatic patients with COPD with a documented spirometric response to glucocorticosteroids or for those with an FEV1 < 50% predicted and repeated exacerbations requiring treatment with antibiotics or oral glucocorticosteroids.

Chronic treatment with systemic glucocorticosteroids should be avoided because of an unfavourable benefit-to-risk ratio.

Other pharmacological treatments-

Vaccines- Influenza vaccines containing killed or live, inactivated viruses are recommended to COPD cases. Pneumococcal polysaccharide vaccine is recommended for COPD patients 65 years and older.

Alpha-1 antitrypsin augmentation therapy- It may be used in young patients with severe hereditary alpha-1 antitrypsin deficiency and established emphysema.

Antibiotics- antibiotics should be used for treating infectious exacerbations of COPD and other bacterial infections.

Mucolytic (mucokinetic, mucoregulator) agents- Although a few patients with viscous sputum may benefit from mucolytics, the overall benefits seem to be very small. Widespread use of these agents is not recommended.

Immunoregulators (immunostimulators, immunomodulators)- Studies using an immunoregulator in COPD show a decrease in the severity and frequency of exacerbations. However, additional studies to examine the long-term effects of this therapy are required before its regular use can be recommended.

Antitussives- Cough, has a significant protective role, thus the regular use of antitussives is not recommended in stable COPD.

Non-pharmacologic treatment-

Rehabilitation- Comprehensive pulmonary rehabilitation programme includes exercise training, nutrition counseling, and education.

(a)Exercise training- All patients with COPD benefit from exercise training programs, improving with respect to both exercise tolerance and symptoms of dyspnoea and fatigue.

(b)Nutrition counseling- Nutritional state is an important determinant of symptoms, disability, and prognosis in COPD; both overweight and underweight can be a problem.

Oxygen Therapy- Oxygen therapy, one of the principal non pharmacologic treatments for patients with Stage IV: Very Severe COPD. It can be administered in three ways: long term continuous therapy, during exercise, and to relieve acute dyspnoea.

The long-term administration of oxygen (> 15 h per day) to patients with chronic respiratory failure has been shown to increase survival.

Ventilatory support- Noninvasive ventilation (using either negative or positive pressure devices) is now widely used to treat acute exacerbations of COPD.

Surgical treatment-

• Bullectomy,
• Lung volume reduction surgery (LVRS),
• Lung transplantation.

Component 4: Manage exacerbations:

Exacerbations of respiratory symptoms requiring medical intervention are important clinical phases in COPD. The most common causes of an exacerbation are infection of the tracheobronchial tree and air pollution, but the cause of approximately one-third of severe exacerbations cannot be identified.

Inhaled bronchodilators (particularly inhaled B2-agonists or anticholinergics), theophylline, and systemic, preferably oral, glucocorticosteroids are effective for treatments for acute exacerbations of COPD.

Patients experiencing COPD exacerbations with clinical signs of airway infection (e.g., increased volume and change of color of sputum, or fever) may benefit from antibiotic treatment.

Noninvasive positive pressure ventilation (NIPPV) in acute exacerbations improves blood gases and pH (a measure of acidity and alkalinity), reduces in-hospital mortality, decreases the need for invasive mechanical ventilation and intubation, and decreases the length of hospital stay.

References-

www.who.int/respiratory/copd/manag

www.who.int/respiratory/copd/GOLD

www.goldcopd.org/uploads/users/fil

Primary prevention (Prevent COPD before it starts):

Primary prevention of COPD requires the reduction or avoidance of personal exposure to common risk factors (Tobacco smoke, occupational exposures, indoor and outdoor air pollution and irritants), to be started during pregnancy and childhood.

Direct and indirect exposure to tobacco smoke should be avoided. The National Tobacco Control Programme was launched by Ministry of Health and Family Welfare (MoHFW), Government of India in 2007- 08, with the objective to bring about greater awareness about the harmful effects of tobacco use and Tobacco Control Laws.

Under the Quit Tobacco Programme supported by Government of India, mobile technology is being utilized in an initiative named as mCessation Programme- QUIT TOBACCO FOR LIFE . The aim of this programme is to reach out and support the tobacco users of all categories who want to quit tobacco use. (www.nhp.gov.in/quit-tobacco-programme
)

Other shared risk factors that include low birth weight, poor nutrition, acute respiratory infections of early childhood, indoor and outdoor air pollutants, and occupational risk factors should be addressed.

The population and individual at risk must be fully informed about a healthy lifestyle, such as healthy nutritional habits, regular exercise and avoidance of tobacco, airway irritants and allergens. Those who are at high risk should avoid vigorous exercise outdoors during pollution episodes. Other sectors within a community must be actively engaged.

Secondary and tertiary prevention which involves early detection of COPD cases, smoking cessation, pulmonary rehabilitation and reduction of personal exposure to noxious particles and gases can reduce symptoms, improve quality of life, and increase physical fitness. It helps in slow progression of COPD and its complications.

Use of Influenza vaccination and Pneumococcal Vaccination in COPD cases helps in decreasing exacerbations.

Persons with advanced COPD should monitor public announcements of air quality and staying indoors when air quality is poor may help reduce their symptoms.

www.who.int/respiratory/publications/strategy

www.nhlbi.nih.gov/health/health-topics/topics

mohfw.nic.in/WriteReadData/l892s/29453109

www.nhp.gov.in/quit-tobacco-programme_ms