Primary care physicians are often the first line of care for chronic obstructive pulmonary disease. Through the assessment of symptoms and risk of future exacerbations, patients can be stratified to aid in selection of initial treatment. By individualising treatment and making timely referrals to specialists, general practitioners are able to effectively diagnose and manage this long-term condition.
Chronic obstructive pulmonary disease (COPD) is a common, preventable and treatable disease characterised by persistent respiratory symptoms and airflow limitation, usually due to cigarette smoking.1 The burden of COPD is staggering in Singapore, where it is the leading cause of respiratory disability and the tenth leading cause of death.2
COPD is a common condition that may present to primary care health providers, who play an essential role in diagnosing and managing this long-term condition.
A 75-year-old man presents with exertional dyspnoea which has been progressive over the past year. He has to stop to catch his breath when traversing the distance between two bus stops. Almost daily, he has cough productive of whitish or yellowish sputum but this is not bothersome for him.
He has attended primary care once in the past year for a respiratory tract infection which required treatment with antibiotics. He has a 30 pack-year smoking history and is still actively smoking. Physical examination including vital signs is unremarkable. Chest x-ray is normal. Spirometry is shown in Figure 1. The COPD Assessment Test (CAT) score is 15.
Figure 1 Flow-volume loop with pre- and post-bronchodilator spirometry values
The patient described in the vignette is a smoker and
demonstrates the chronic respiratory symptoms which
are typical of COPD.
However, history and physical examination alone are not sufficient to make the diagnosis of COPD. Further investigations are needed to rule out other respiratory
diseases that may present in a similar manner, as well
as to confirm the diagnosis.
Chest x-ray is usually non-contributory in the diagnosis of COPD but is required to evaluate for
other diseases such as congestive heart failure,
tuberculosis, lung cancer and bronchiectasis. The confirmation of COPD requires spirometry testing. Specifically, the ratio of post-bronchodilator forced
expiratory volume in one second (FEV1) to forced vital capacity (FVC) should be less than 0.7.The Global Initiative for Chronic Obstructive
Lung Disease GOLD Grade (1 to 4) is based on the
post-bronchodilator FEV1 % predicted, with lower
FEV1 % predicted values indicating a higher or more
Whilst the GOLD grade predicts mortality and provides
a useful gauge of the patient’s current status in the
long-term disease trajectory, other patient-related
outcomes are usually assessed during a consult to
guide selection of initial pharmacologic treatment.
The two core patient-related outcomes of symptoms or impact and risk of exacerbation should be assessed
at each visit.
1. Symptoms or impact
This can be assessed using either the modified Medical Research Council (mMRC) dyspnoea scale or the COPD assessment Test (CAT).
mMRC is a simple scale measuring dyspnoea
when walking on level ground, ranging from 0
to 4 (Table 1), with mMRC scores of 2 or above indicating a higher symptom burden.
The CAT score quantifies the symptomatic impact
of COPD not only with respect to dyspnoea but
also other domains such as cough, mucous, chest
tightness, activities, sleep and energy. The CAT
score ranges from 0 to 40 with higher scores
indicating higher impact of symptoms. The patient
presented in the clinical vignette had a CAT score
For the purpose of selecting initial treatment, a CAT
score of 10 or more indicates a higher symptom
Dyspnoea only with strenuous exercise
Dyspnoea when hurrying or walking up a slight hill
Walks slower than people of the same age because of dyspnoea or has to stop for breath when walking at own pace
Stops for breath after walking 100 yards (91 m) or after a few minutes
Too dyspnoeic to leave the house or breathless when dressing
Table 1 Modified Medical Research Council (mMRC) dyspnoea scale
2. Risk of exacerbation
Whilst many factors may lead to an exacerbation,
the strongest predictor for a future exacerbation
is a history of previous exacerbation. The patient described in the vignette had experienced one
exacerbation-like event which was treated as
a respiratory tract infection by his primary care
Based on symptoms and risk of future exacerbations,
patients can be stratified into different groups (ABCD)
for initial treatment (Figure 2).
The patient in our vignette (one moderate exacerbation,
CAT 15) falls under Group B, and may be commenced
on a long-acting bronchodilator in the first instance,
either a long-acting beta2-agonist (LABA) or long-acting
muscarinic antagonist (LAMA).
Multiple inhaler devices are available for each class
of medication, and the selection of inhaler device
should be tailored to the individual patient to ensure
that inhalers are used correctly. COPD outcomes
are crucially dependent on delivering good basic
care, and the adverse impact of inhaler misuse or
nonadherence should not be underestimated.
Influenza and pneumococcal vaccinations are also
recommended for COPD patients to reduce frequency
and severity of infective exacerbations.
Non-pharmacological management of COPD is even
more important than pharmacological management.
Whilst pharmacological therapies have not been
found to have an impact on mortality, some non-pharmacological
interventions have a positive effect
on survival in COPD, chiefly smoking cessation, which
leads to slowing of the rate of lung function decline.
Even a few minutes invested on smoking cessation
counselling by physicians is associated with improved
quit rates among smokers.
LAMA: long-acting muscarinic antagonist; LABA: long-acting beta2-agonist; ICS: inhaled corticosteroids
Where clinically indicated, GPs should refer COPD patients for specialist advice. Referral is appropriate at all stages of the disease, not only for those who are most disabled by the disease.
Possible indications for GP referral include, but are not limited to:
Specialists can perform assessments for interventions such as:
COPD patients may also benefit from a range of hospital-based services including case management, social work, pulmonary rehabilitation, occupational therapy, dietetics, community care, and palliative care.
Once stable, the care of COPD patients may be transferred back to primary care.
In conclusion, COPD is a condition commonly
encountered in primary care. The diagnosis of COPD
should be confirmed on spirometry as far as possible. Combined assessment of symptoms (using either the
mMRC or CAT score) and risk of future exacerbations
(based on history of previous exacerbations) is used
to stratify patients for the purpose of selecting initial
Referral for specialist advice is appropriate at all
stages of disease, not only for those who are most
disabled by the disease.
Dr Anthony Yii earned his medical degree from the University of Cambridge (UK) in 2009
and subsequently completed his specialty training in respiratory medicine in 2017. His scope
of practice includes airway diseases (asthma, chronic obstructive pulmonary disease and
bronchiectasis and pulmonary infections), interstitial lung disease, non-invasive ventilation,
pleural diseases, diagnosis of lung cancer and bronchoscopy.
Apart from his clinical commitments, Dr Yii is active in pulmonology research with a focus
on airway diseases and allergy and has been an invited reviewer for several international
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