Diagnosis of COPD

There is no one single test that can confirm a diagnosis of COPD.

In addition to a relevant clinical history and spirometry, at the time of initial diagnosis the patient should undergo the following investigations [4]:

• Chest x-ray (CXR) to exclude other pathology
• Full blood count (FBC) to identify anaemia and polycythaemia
• Calculation of body mass index

Additional investigations to consider depending on individual factors may be [4]:

• Serial home peak flow measurements to exclude asthma if diagnostic doubt
• Alpha 1 antitrypsin if early onset of symptoms, minimal smoking history or a relevant family history
• CT chest to investigate CXR abnormality and/or exclude pulmonary embolism
• Echocardiogram, ECG and BNP to assess for cor pulmonale
• Sputum culture in cases of chronic productive cough

Differentiating COPD and asthma

Table 2: NICE Guideline. Clinical symptoms that may help differentiate COPD and asthma [4]