COPD FACTS

 CHRONIC OBSTRUCTIVE PULMONARY DISEASE: 10 QUESTIONS A GP MUST KNOW

1. What do you mean by Chronic Obstructive Pulmonary Disease (COPD) and what are its types?

COPD is a disease prevalent among middle aged and elderly individuals causing considerable morbidity. This disorder is characterized by progressive air flow limitation that is not fully curable and is associated with an abnormal inflammatory response of the lungs to noxious particles and gases. COPD is both preventable and treatable with some significant extra pulmonary effects contributing to severity in individual patients. Because of the concurrent extra pulmonary effects, COPD is considered as a systemic disease. COPD includes chronic bronchitis and emphysema of which chronic bronchitis is defined clinically whereas emphysema is defined pathologically. Chronic bronchitis is defined as the presence of a chronic productive cough on most of the days for three months, in each of two consecutive years, in a patient in whom other causes of chronic cough have been excluded.  Emphysema is defined as abnormal, permanent enlargement of the airspaces distal to the terminal bronchioles, accompanied by destruction of their walls without obvious fibrosis.

2. How does COPD evolve in a patient and what are its risk factors?

Inhalation of cigarette smoke or smoke from biomass fuels causes lung inflammation which in turn induces parenchymal destruction and disruption of normal repair process. Pathological changes in COPD include chronic inflammation with increased number of specific inflammatory cell lines and structural changes secondary to repeated injury and repair. Systemic inflammation may accompany these changes and could play an important role in the causation of multiple comorbid conditions. Airflow limitation is caused by a mixture of small airway diseases and parenchymal destruction. Inflammation and narrowing of peripheral airways leads to decreased FEV₁. These pathological change leads to gas trapping and progressive airflow limitation.

Environmental factor becomes the greatest risk for development of COPD. Genetic factors to an extent play a role in the pathogenesis of COPD. Hence it can be concluded that this disease usually arises as a result of gene-environment interaction. The male sex and increasing age are particularly at risk. Cigarette smoking and air pollution resulting from burning of wood and biomass fuels are the major known risk factors for COPD. However there are other factors such as nutrition, infection and occupational exposure which also play a role in its causation.

Cigarette smoking is by far the most commonly encountered risk factor for COPD. Cigarette smokers have a high annual rate of decline of FEV₁ at a rate of 50 ml which is nearly double the value of 30 ml annually present in nonsmokers. In nonsmokers the FEV₁ begins to decline at 30-35 years of age and this may occur earlier in smokers. The risk for COPD in smokers is dose-related. Age at starting to smoke, total pack-years smoked, and current smoking status are predictive of COPD mortality. It is observed that not all smokers develop clinically significant COPD, which suggests that genetic factors may modify the risk.

Other risk factors include passive smoking, exposure to biomass fuel, occupational pollutants, infections and genetic factors. About 80% of the COPD is attributed to smoking, and 15% is due to work-related conditions. Even though a lesser percentage has genetic factors causing COPD, it is mostly due to interplay between environmental and genetic factors.

3. What signs/symptoms can a patient with COPD present to a doctor?

Chronic and progressive dyspnea is the most characteristic symptom of COPD. Cough with sputum production is seen in 30% of patients only. These symptoms may vary day to day and progress over a period of many years. Significant airflow limitation may also be present without chronic dyspnea and/or cough and sputum. Patients may seek medical attention either because of chronic, progressive symptoms or due to acute worsening in exacerbations. Audible wheeze is a predominant symptom associated with bronchial obstruction. This may also vary according to the type and severity of involvement. Absence of wheeze does not rule out COPD as this may not be evident in emphysema.

Fatigue, weight loss and anorexia are associated with long standing COPD. Cachexia is a frequent finding in COPD and is associated with poor functional capacity and increased mortality. It has been observed that 10 to 15 per cent of patients with mild to moderate COPD have significant weight loss whereas the weight loss is observed in 50 per cent of patients with severe COPD.

Chronic bronchitis patients are blotted and cyanotic (Blue bloater) whereas emphysema patients are lean and polycythaemic (Pink puffer). There will be features of hyperinflation in the form of barrel chest, low flat diaphragm and hyper-resonant percussion notes. Auscultation may demonstrate diffuse expiratory polyphonic wheezes. Physical signs of pulmonary hypertension and right heart enlargement/ failure can be elicited in appropriate circumstances.

In some patient a clear distinction between chronic asthma and COPD is not possible. In such patients it is assumed that asthma and COPD coexist (Asthma- COPD overlap). This accounts for approximately 15–25% of the obstructive airway diseases and patients experience worse outcomes compared to asthma or COPD alone.

4. How should a physician approach to a patient with symptoms suggestive of COPD that arrives at his/her clinic for the first time?

COPD is suspected in any patient who has chronic cough with sputum production for at least 3 months in 2 consecutive years or progressive dyspnoea with or without exposure to risk factors. Making a diagnosis relies on clinical judgment based on a combination of history, physical examination and confirmation of the presence of airflow obstruction using spirometry. In clinical practice the progressive and disabling nature of the illness is often overlooked and hence ignoring COPD as simple bronchitis or asthma.

Consider a diagnosis of COPD if any of the following indicators are present.

1)      Persistent Progressive dyspnea that is worsened by exercise.

2)   Chronic cough (intermittent and unproductive also included)

3)   Chronic sputum production

4)   History of exposure to risk factors like tobacco smoke, smoke from household cooking and heating fuels, occupational dusts and chemicals.

5)   Family history of COPD

The initial investigation of choice in an obstructive airway disease is spirometry. If post bronchodilator FEV₁/FVC is <0.70, it confirms the presence of persistent airflow limitation and suggest a diagnosis of COPD.

Criteria for assessing the severity of airflow obstruction (based on the percentage predicted post bronchodilator FEV₁) are as follows:

• Stage I (mild): FEV₁ 80% or greater of predicted
• Stage II (moderate): FEV₁ 50-79% of predicted
• Stage III (severe): FEV1 30-49% of predicted
• Stage IV (very severe): FEV₁ less than 30% of predicted or FEV₁ less than 50% and chronic respiratory failure.

 Chest X-Ray is an important tool even though not specific; X- ray can give you many clues such as

1)         Hyperinflation- Low flat diaphragm, widened rib spaces, tubular heart, hyper-translucency, increased bronchovascular markings and increased retrosternal airspace in lateral view.

2)         Presence of air containing spaces or bullae.

3)         Enlarged proximal pulmonary vessels

CT Thorax is seldom employed as a first level investigation, but is useful to identify and locate bullous changes in the lung.

Arterial blood gas estimation may be needed in acute exacerbation which will show hypoxemia and/ or hypercarbia.

     

5. What investigations should a GP order for a patient of COPD and how could he/she reach a definitive diagnosis?

A detailed history may point to a diagnosis in majority of cases. The nearest differential diagnosis is asthma which can be identified by the episodic nature of breathlessness. Pulse oximetry can pick up hypoxia and peak expiratory flow measurement will give an idea about airfow obstruction. X-Ray chest if available will give certain clues as mentioned earlier regarding hyperinflation which is a feature of COPD. If presented in exacerbation, elevated total WBC count may suggest acute infection as a cause for exacerbation.

6. How should one design a therapy for a COPD patient? What medications can a GP prescribe to such a patient at his/her level?

Physician treating a COPD patient should understand that it is not a curable disease and should not offer cure or attempt overenthusiastic treatment with a curative intent. Patients of COPD should understand the nature of disease, risk factors for its progression and the role that their health care workers must play in order to achieve optimal management and outcomes. Pharmacologic and non -pharmacologic therapies should be guided by disease severity and aim to control symptoms, decrease exacerbations, and improve patient’s functional quality of life.  Aims of treatment

• Control of symptoms.
• Enable the patients for daily activities
• Improve quality of life
• Improve exercise tolerance
• Prevent disease progression
• Prevent and treat exacerbations
• Prevent complications
• Reduce mortality

To guide management COPD is categorized based on symptoms and risk of exacerbations.

• A= Less symptoms, Low risk
• B= More symptoms, low risk
• C= Less symptoms, high risk
• D= More symptoms, High risk.

General practitioners can treat COPD patients with bronchodilators. In group A treat with inhaled form of either short acting beta agonists or short acting anti cholinergics. Oral Theophylline can be used as add on. In group B inhaled long acting beta agonists or anti cholinergics may be used. If response is suboptimal these two drugs can be combined. Theophilline may also be added and short acting beta agonist can be used to control acute symptoms. In group C and D inhaled corticosteroid may be added to LABA and LAMA. Alternate drugs such as Roflumilast may be added if response is not satisfactory. In group D long term oxygen therapy may be initiated and any possibility of surgical treatment may be considered. All patients need pulmonary rehabilitation to improve exercise tolerance. Rarely surgery is of help in selected patients such as those who have large bullous emphysema or those having heterogeneous involvement with severe hyperinflation.

7.  How does acute exacerbations of COPD present? What is meant by decompensated COPD?

COPD exacerbations are important because they are associated with significant morbidity, health care cost and mortality. Acute exacerbation is caused by several factors of which most important are bacterial or viral respiratory tract infections. Air pollution is another contributing factor in a minority of cases. The cause of exacerbations cannot be identified in one-third of cases. Patients with two or more exacerbations per year are classified as frequent exacerbators.

COPD exacerbation is defined as an event in the natural course of the disease characterized by a change in the patient’s baseline dyspnea, cough, and/or sputum that is beyond the normal day-to-day variations, is acute in onset, and may warrant a change in regular medication in patients with underlying COPD.

Cardinal symptoms of exacerbation are

1. Increased Sputum volume

2. Sputum purulence

3. Increased dyspnoea

Anthonisen et al graded these exacerbations into 3 types.

·         Type I- all 3 cardinal symptoms are present

·         Type II- 2 cardinal symptoms are present

·         Type 3 one cardinal symptom + one of the followings

1. An upper respiratory infection within the past 5 days.

2. Fever without other cause.

3. Increased wheezing or cough or an increase in heart rate or respiratory rate by 20% compared with baseline.

Sudden worsening of COPD with respiratory failure or cardiac failure denotes decompensation. This usually accompanies acute exacerbations. These patients are identified by the presence of dyspnea, tachypnea, cyanosis and edema.

Causes of an acute decompensation of a COPD Patient are

• Superimposed infection
• Continued smoking
• Non-compliance
• Lack of usual medications or oxygen therapy
• Spontaneous pneumothorax

8. What could be the long term complications of the different forms of COPD?

Chronic obstructive pulmonary disease (COPD) being a chronic, progressive disease, there are many local and systemic complications contributing to its morbidity and mortality. Control of progression and early prevention are the optimal strategies to avoid such complications.

Complications include

● Pneumonia

● Pulmonary Hypertension and Cor pulmonale

● Pneumothorax

● Giant Bullae

● Cardiovascular Disease

● Lung cancer

● Sleep Disorders

● Osteoporosis

● Diabetes

● Psychiatric complications –Depression and / or Anxiety

9. When should a GP seek specialist referral in the management of COPD?

Referral to specialist generally has the purpose to confirm diagnosis, perform additional investigations, optimize and initiate treatment or exclude other illnesses.

Indications are

• Disease onset age <40 years
• Frequent exacerbation despite adequate management
• Rapidly progressive course of disease
• Severe COPD
• Need for oxygen therapy
• Onset of comorbid illness
• Possible indication for surgery

10. What should patients of COPD be advised as regards prevention and rehabilitation of their illness? Can moderate exercise help such patients?

Prevention of COPD is crucial as it is not a curable condition. Prevention usually focuses on smoking cessation. Primary prevention of COPD requires the reduction or avoidance of personal exposure to common risk factors. Avoidance of direct and indirect exposure to tobacco smoke is of primary importance for healthier lungs. Other shared risk factors that should be addressed include low birth weight, poor nutrition, acute respiratory infections of early childhood, indoor and outdoor air pollution and occupational risk factors. Secondary and tertiary prevention involves avoidance of allergens and non-specific triggers, optimal pharmacological treatment, including the use of anti-inflammatory medication. Influenza vaccination reduces lower respiratory tract infections and death in patients with COPD. Pneumococcal polysaccharide vaccine is useful in COPD patients 65 years and older and in younger patients with significant comorbid conditions such as cardiac disease.

Pulmonary rehabilitation includes lower and upper extremity exercise conditioning, breathing retraining, education, and psychosocial support. Smoking cessation, oxygen therapy, bronchodilators, antibiotic use, nutritional support, and respiratory muscle training are also being included in many rehabilitation programs. The primary components of a comprehensive program are:

·         Patient assessment.

·         Patient exercise training.

·         Patient education.

·         Program evaluation.

·         Maintenance.

Patients with chronic obstructive pulmonary disease (COPD) often try to reduce their physical activity because of the fear of worsening dyspnea. This lead to progressive deconditioning due to inactivity, and gradually patient become dyspnoeic even at minimum physical demands. Pulmonary rehabilitation aims to break this cycle. Benefits of pulmonary rehabilitation include decreased dyspnea, improved health-related quality of life, fewer days of hospitalization, and decreased health-care cost. Initiation of a rehabilitation schedule during or immediately after hospital admission for acute on chronic respiratory failure reduces the extent of functional decline and leads to early recovery.