CHRONIC OBSTRUCTIVE PULMONARY DISEASE: 10
QUESTIONS A GP MUST KNOW
- 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.
- 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.
- 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.
- 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.
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
Arterial
blood gas estimation may be needed in acute exacerbation which will show hypoxemia
and/ or hypercarbia.
- 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.
- 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.
- 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
- 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
- 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
- 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.
