Diagnosis of COPD

Most patients will have been smoking cigarettes for many years (probably in excess of 20 pack years). The two main symptoms of COPD are breathlessness and cough which may or may not be productive of purulent sputum. A history of persistent productive cough or recurrent infections especially in the winter months is common. The cough is usually worse in the mornings but bears no relationship to the severity of the disease. Excessive sputum volumes are unusual and may suggest bronchiectasis. Haemoptysis should alert the physician for the presence of a carcinoma of the bronchus as this is a frequent co-morbidity in patients with COPD, but is often just due to infective exacerbations
Breathlessness is a common feature of acute infective exacerbations, but breathlessness during normal every day activity develops insidiously over many years. Wheeze is often an accompanying feature of breathlessness and may be erroneously attributed to asthma.

Weight loss is common in patients with long standing disease with predominately emphysema (the old fashioned pink puffer), although weight gain may also be a feature suggesting chronic hypoxemia and the onset of cor pulmonale (the blue bloater). Patients can rarely be classified as pink puffers or blue bloaters, and the two states do not have any pathophysiological correlation. Therefore the usefulness of this classification is questionable and its use is discouraged by both sets of guidelines.

There are no specific findings on examination, although signs of hyperinflation of the chest are highly suggestive of emphysema. These include a barrel shaped chest, use of accessory muscles of respiration, reduction of the cricosternal distance, tracheal tug, paradoxical indrawing of the lower ribs on inspiration, intercostal recession, hollowing out of the supraclavicular fossae, pursed lip breathing and reduced expansion. In addition the patient may have hyperresonant lung fields, prolongation of expiration, especially forced expiration >5s, and audible wheeze. None of these signs are specific to COPD and do not correlate very well with the severity of the disease which emphasizes the need for objective assessment. Their presence, however, should alert the physician to the possible diagnosis of COPD.

As the disease progresses, signs of right ventricular dysfunction may develop because of the effects chronic hypoxemia and hypercapnia which include peripheral oedema, raised jugular venous pressure, hepatic congestion, and the presence of metabolic flapping tremor. Despite the widely held belief that these signs are due to right ventricular failure, the pathophysiology cor pulmonale is likely to be due to altered renal function giving rise to salt and water retention rather than cardiac dysfunction secondary to pulmonary hypertension.