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Publications
Tiova Scope - Issue - 1
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COPD A SERIOUS CHALLENGE |
There was a time when chronic obstructive pulmonary disease (COPD) was a relatively unknown term. Today, its prevalence is on the rise and deaths due to COPD are increasing in alarming numbers worldwide. It is expected to be the third leading cause of death by the year 2020, moving up from its current fourth position.
One Indian study has reported a gross estimate of nearly 12 million people affected by COPD, above the age of 30, with a prevalence rate of 5 percent among males and 3 percent in women2. All available data, however, indicate that COPD is often under-diagnosed, diagnosed late in its course, and/or misdiagnosed as asthma.
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Impact of COPD |
The impact of COPD on the health care system is overwhelming. It is particularly so with respect to the number of emergency visits and hospital re-admission rates. As of now, COPD management is focused on managing acute exacerbations and not on long-term maintenance therapy. The high incidence of hospital admission is due to inadequate outpatient management of COPD.
The debilitating nature of COPD contributes to absence from work, decreased efficiency and reduced quality of life. The serious impact of COPD has on life is often not immediately apparent, but becomes evident only over a period of time. The disease is often diagnosed at a stage when there is significant decline in lung function. The physician's proactive approach is crucial for early detection and effective management. Patient education and counseling make a vital contribution to improving the quality of life.
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"Data reveal that
the number of hospital admissions, duration
of hospital stay and doctor visits are
greater for COPD
than Asthma"
- Prof. Peter Barnes,
Imperial College, London, U.K.
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"New research & exciting findings
suggest that the
picture of COPD
may not be as bleak
as previously
thought "
- Dr. Bartolome Celli,
Tufts University, School of Medicine, Boston, USA
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COPD re-defined
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| COPD is a disease state characterised by airflow limitation that is not fully reversible. The airflow limitation is usually both progressive and associated with an abnormal inflammatory response of the lung to noxious particles or gases.5 The key words to be noted are “not fully reversible” and “progressive”. |
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What is the underlying problem in COPD?
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The basic pathophysiologic process in COPD consists of:
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Increased mucus production and reduced mucociliary clearance
- leading to cough and sputum production
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Loss of elastic recoil.
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Expiratory air flow limitation is a hallmark of COPD and is due to airway narrowing caused by increased smooth muscle tone.
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Pulmonary hyperinflation.
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Gas exchange abnormalities, producing hypoxemia, and later on, hypercapnia.
Fig 1: Summary of pathogenic mechanism in COPD
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How is a diagnosis of COPD made?
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A diagnosis of COPD is usually made on "exclusion of asthma" (Table 1: The difference between COPD and Asthma). It is necessary to differentiate between COPD and asthma because:
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The two diseases differ in their aetiology.
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Different with respect to the inflammatory cells, mediators and inflammatory consequences.
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Different sites are affected in the lungs.
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They respond differently to treatments.
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Table 1:Difference between COPD and Asthma
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| Parameter |
COPD |
Asthma |
| Onset |
Mid-life |
Early in life (often childhood) |
| Symptoms |
Slowly progressive |
Vary from day to day and peak in the night/early morning |
| History |
Long smoking history or exposure to smoking and bio mass fuel |
History of allergy, rhinitis and/or eczema |
| Inflammatory cells |
Neutrophils |
Eosinophils |
| Airway hyperresponsiveness |
Absent |
Positive |
| Airflow limitation |
Largely irreversible |
Largely reversible |
COPD should be considered in any individual who present with characteristic symptoms and history of exposure to a risk factor of the disease, especially smoking.
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Table 2:Key indicators for considering a COPD diagnosis5
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| Chronic cough |
Present intermittently or every day
Often present throughout the day; seldom only nocturnal |
| Chronic sputum production |
Any pattern of chronic sputum production may indicate COPD |
| Acute bronchitis |
Repeated episodes |
| Dyspnoea |
Progressive (worsens over time). Persistent (present every day)
Worse on exercise. Worse during respiratory infections |
| History of exposure to risk factors |
Tobacco smoke (including beedi)
Occupational dusts and chemicals
Smoke from home cooking and heating fuel. |
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Table 3: Classification of COPD severity based on bronchodilator reversibility5
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| FEV1 ³ 80% predicted |
Mild disease |
FEV1/FVC < 70% |
| FEV1 ³ 30% < 80% predicted |
Moderate disease |
FEV1/FVC < 70% |
| FEV1 < 30% predicted |
Severe |
FEV1/FVC < 70% |
FEV1=Forced expiratory volume in one second; FVC= Forced Vital Capacity
The prognosis is also directly related to the post bronchodilator FEV 1 and inversely related to the patient's age. The post-bronchodilator values correlate better with survival than the pre-bronchodilator value. 1
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| Age |
FEV1 |
3-year survival rate |
| Under 60 |
About 50% predicted |
90% |
| Over 60 |
About 50% predicted |
80% |
| Over 60 |
40-49% predicted |
75% |
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It is now widely recognised that COPD differs from asthma, and that the nature of the lung disease in COPD leads to airflow limitation that is far less reversible and far more progressive than the limitations in asthma. These differences have an important bearing on treatment.
In Asthma the Backbone of treatment is inhaled cortricosteroids.
In COPD the Backbone of treatment are inhaled bronchodilator.
Management of COPD is largely ‘symptom-driven' and aims to improve the patient's quality of life.
An effective COPD management plan include four components:
1. Assess and monitor disease
2. Reduce risk factors
3. Manage stable COPD
4. Manage exacerbations
While disease prevention is the ultimate goal, once COPD has been diagnosed, effective management should be aimed at:
- Preventing disease progression
- Relieving symptoms
- Improving exercise tolerance and Improving health status
- Preventing and treating complications and exacerbations
- Reducing mortality
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Oral steroid trial
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Although several guidelines on diagnosis and management of COPD have suggested that a trial of oral steroid predicts responsiveness to inhaled corticosteroids in COPD patients, this is now being re-assessed.
A better role for an oral steroid trial may be to determine whether a patient suffers from asthma or from COPD, depending on how he or she responds spirometrically or even clinically symptom to aggressive anti-inflammatory treatment. (Fig 2)
Figure 2. Obstructive airways disease algorithm for symptomatic patients and/or those with significant airflow obstruction. Oral steroid trial = prednisone 30 mg per day for 2-3 weeks. Reversibility = change in baseline FEV 1 following oral steroid trial
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COPD management |
The GOLD guidelines offer a valuable framework for COPD management. In Fig. 3, an approach to COPD treatment is depicted in stepwise increments, implying inadvertently that therapy begins in a limited fashion and is titrated gradually upwards.
Figure 3: COPD treatment according to Gold Guidelines and Disease Severity |
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• Avoid risk factors |
• Avoid risk factors
• Bronchodilator p.r.n. |
• Avoid risk factors
• Bronchodilator p.r.n.
• Regular bronchodilator
• Consider ICS
• Rehabilitation |
• Avoid risk factors
• Bronchodilator p.r.n.
• Regular bronchodilator
• Consider ICS
• Rehabilitation
• Oxygen
• Surgery |
At almost all stages of treatment, bronchodilators are required when needed (in very early stages) or regularly (as the disease progresses).
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Conclusion |
COPD is a major cause of death and disability throughout the world. While there is not yet a cure for COPD, its progress can be slowed and its effects minimised. With proper medications, appropriate supplementation, consistent physical activity and the right attitude, most patients can regain some lung function and enjoy a happier and more productive life.
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References
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1. Primary Care Respiratory Journal 2002; 11: S15-S19
2. The Indian J of Chest Disease and Allied Sciences 2001; 43; 139-147
3. Chest 2000; 117: 1S-69S
4. Comprehensive Management of COPD 2002; 1-65
5. Global Initiatives for COPD, NHLBI/WHO Workshop report 2001; 1-100
6. Asthma J 2002; 7: 182-4
7. Bellamy D and Rachel Booker, COPD in Primary Care 2000:45-57
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