Investigation in chronic lung disease - Too much, too little, just right!

BACKGROUND

Lung problems are common in general practice. History and examination are invaluable; however considered selection of investigations can assist the clinician to reach a diagnosis.

OBJECTIVE

To outline the indications for common respiratory investigations to assist in selecting the most appropriate investigation for a clinical problem related to chronic lung disease.

DISCUSSION: The vast majority of problems related to chronic lung disease can be assessed with a full history and examination, a plain chest X-ray, a spirometer and a pulse oximeter. Chest X-ray should always be the initial radiological test. It can distinguish pneumonia from bronchitis and diagnose breathlessness caused by pneumonia, heart failure, pneumothorax, pleural effusion and interstitial lung disease. Computerised tomography scanning is not a useful test in investigation of symptoms such as breathlessness or cough when a chest X-ray is normal. Spirometry can be useful in the evaluation of chronic cough, wheezing, breathlessness or chest pain. Baseline oximetry should be performed on all dyspnoeic patients and those with abnormal spirometry.