Most individuals with COPD are not diagnosed until the disease is well advanced. Targeted testing of symptomatic individuals with risk factors for the development of COPD followed by intensive smoking cessation counselling can change the progression of disease.
Mass screening of asymptomatic individuals for COPD is not supported by the current evidence and therefore is not recommended. The following criteria are recommended to help the family physician decide who to target for spirometry in their practice so as to establish early diagnosis in individuals at risk of COPD.
Patients who are older than 40 years of age and who are current or ex-smokers should undertake spirometry if they answer yes
to any one
of the following questions:
- Do you cough regularly?
- Do you cough up phlegm regularly?
- Do even simple chores make you short of breath?
- Do you wheeze when you exert yourself, or at night?
- Do you get frequent colds that persist longer than those of other people you know?
Episodes of acute bronchitis in a smoker may represent the first clinical presentation of COPD – spirometry should be obtained after the acute episode has resolved and the patient is clinically stable.
Tobacco consumption should be quantified:
Individual susceptibility for the development of COPD varies, so no minimum number of pack years is required to place an individual at risk.
COPD management decisions should be made on an individual basis and should not be based exclusively on spirometry results but also on an assessment of severity of dyspnea and disability, which are assessed by using the Medical Research Council dyspnea scale ( and ).
The Medical Research Council dyspnea scale
Canadian Thoracic Society chronic obstructive pulmonary disease (COPD) classification of severity by symptoms and disability*, and impairment of lung function
Clinical assessment begins with a thorough history and physical examination. Occupational or environmental exposures to cigarette smoke and other lung irritants should be recorded. Symptoms and signs related to the COPD, complications (eg, leg edema in cor pulmonale) and comorbidities should be identified. Inquiry concerning frequency and severity of exacerbations is crucial to management decisions. Current medical treatment should be reviewed. Physical examination, although important, is not usually diagnostic except in the presence of very severe airflow limitation.
Postbronchodilator spirometry is required to evaluate the presence and severity of airway obstruction (). Additional pulmonary function and exercise tests may be undertaken in selected patients for a more complete clinical characterization of the COPD phenotype. Arterial blood gas measurements should be considered in patients with forced expiratory volume in 1 s (FEV1) of less than 40% predicted (with a resting arterial oxygen saturation of less than 90%) to assess for evidence of hypoxemia or hypercapnia. Chest x-rays and other investigations are not diagnostic of COPD but are often required to assess comorbidities.
COPD and asthma are fundamentally different
In a small proportion of patients, diagnostic differentiation can be challenging and may require additional investigation or specialist referral. Clinical differences between asthma and COPD can usually help in making a correct diagnosis (). Patients with a large improvement in FEV1 (eg, greater than 0.4 L) acutely following inhaled short-acting bronchodilators or following treatment with inhaled or oral steroids likely have an asthmatic component.
Clinical differences between asthma and chronic obstructive pulmonary disease (COPD)
Other conditions included in the differential diagnosis of older patients presenting with progressive dyspnea include cardiovascular conditions, pulmonary vascular disease, severe deconditioning, obesity, anemia, interstitial lung disease and neuromuscular disease.