Prospective Evaluation of Patients with Chronic Dyspnea in a Pulmonary Out-Patient Clinic Using an Algorithm

Objective: The aim of this study was to evaluate the causes of chronic dyspnea in patients of an outpatient clinic prospectively and to implement an efficient diagnostic approach.Methods: A prospective study was performed with an algorithm for chronic dyspnea.After the patients were evaluated by the history and physical examination, blood tests, chest X-ray (CXR), and spirometry were performed in all cases.The methacholine inhalation challenge test was proposed as a diagnostic test in situations where clinical asthma is suspected and spirometric findings are non-obstructive.All patients whose basic tests were normal, high resolution computed tomography (HRCT), computed tomography (CT), pulmonary angiography, and transthoracic echocardiography (TTE) were performed as second step tests.Results: As basic tests were non-diagnostic in 58 patients, second step tests were performed.Twelve patients with high clinical probability of asthma were positive on the methacholine inhalation challenge test and responded to asthma treatment.With this algorithmic approach, a final diagnosis was reached in 90% of the patients.The most frequent diagnoses were asthma (27%), chronic obstructive pulmonary disease (COPD) (17%), bronchiectasis (13%), and heart failure (10%).Conclusion: As a result of this comprehensive protocol, most causes of chronic dyspnea were found to be airway and heart diseases.We would suggest that CXR and spirometry can be performed as first step tests.We consider that when the results of the basic tests are normal, both TTE and HRCT are very useful tests.