Pulmonary function tests

Abstract

Measurement of lung volumes is not helpful in the detection of pulmonary disease in AIDS patients. Spirometry is useful in detecting airflow obstruction, which is a common and sometimes unexpected finding in the AIDS population. Measurement of the diffusing capacity of the lung for carbon monoxide and exercise alveolar-arterial oxygen gradient is a highly sensitive means of detecting Pneumocystis carinii pneumonia in the human immunodeficiency virus-infected individual. Both tests are clinically useful when the resting arterial blood gas and/or chest x-ray are normal in symptomatic patients. Since the exercise test is more specific for P. carinii pneumonia than is the diffusing capacity, it can be helpful in evaluating patients who have known lung disease and progressive symptoms.