Diagnosis

A clinical diagnosis of COPD should be considered in any patient who has dyspnea, chronic cough or sputum production, and/or a history of exposure to risk factors for the disease (Figure 1).1

Symptoms, a history of risk factors, and spirometry all contribute to the diagnosis of COPD.

Figure 1. Symptoms, a history of risk factors, and spirometry all contribute to the diagnosis of COPD1
FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity

Medical history

On presentation of a patient with the primary symptoms of COPD (dyspnoea, chronic cough and sputum production), a detailed medical history should be taken to assess the patient’s exposure to risk factors e.g. smoking, family history of COPD or other chronic respiratory disease, the pattern of symptom development, history of exacerbations or previous hospitalizations for respiratory disorder, presence of comorbidities, impact of disease on patient’s life, social and family support available to the patient and the possibility of reducing risk factors e.g. smoking cessation.1

Physical examination

A number of physical signs may be present in COPD, but are not usually present until significant lung impairment has occurred, and their absence does not exclude the diagnosis.1

A list of physical signs in COPD

  • Increased lung volumes due to hyperinflation may manifest as a barrel shaped chest, abdominal distension and decreased hepatic dullness to percussion.
  • Dyspnoea at rest – may manifest itself as an increased respiratory rate (more than 20 breaths per minute) and may also be accompanied by the use of the accessory muscles of respiration.
  • Central cyanosis – may manifest as a bluish discoloration of the lips
  • Pursed-lip breathing (the so called “pink puffer”) – reflects a physiological reflex to increase end-expiratory pressure, thereby reducing airway collapse secondary to the decreased elastic recoil associated with emphysema.
  • In severe disease, increased fluid retention is associated with impaired right heart function and metabolic derangement resulting in raised jugular venous pressure (JVP) and ankle oedema. When seen in this context the syndrome is referred to as ‘cor pulmonale’.
  • Auscultation (listening to the chest) may reveal wheeze, decreased breath sounds, rales and rhonchi.
  • Due to the obstructive nature of the disease, prolonged forced expiratory time may be clinically apparent, but lung function testing is the gold standard for detecting obstruction.

Measurement of airflow limitation

As a reproducible, standardised and objective way of measuring airflow limitation, spirometry is the gold standard for confirming a diagnosis of COPD. Spirometry should be performed after the administration of a bronchodilator in order to minimise variability, and ensure airways are maximally dilated when the test is performed. According to criteria published in the GOLD strategy document, a post-bronchodilator ratio of FEV1 to forced vital capacity (FVC) of less than 0.70 confirms a diagnosis of COPD.1

Additional investigations

Further investigations may be necessary to confirm that the respiratory symptoms and airflow limitation result from COPD rather than other chronic lung or cardiac conditions (e.g. bronchiectasis, lung cancer, chronic heart failure).2

  • Chest x-rays are useful for excluding alternative diagnoses such as heart failure.
  • Arterial blood gas measurement may be appropriate in patients with an initial diagnosis of advanced COPD.
  • Alpha-1 antitrypsin deficiency screening should be considered in patients from areas where this genetic disorder is common.1,2

Diagnosis may also be helped by using specifically designed questionnaires and algorithms.3,4