Evaluation of exertional dyspnea in the active duty patient: the diagnostic approach and the utility of clinical testing.

Introduction: Minimal information currently exists on how clinicians should approach the evaluation of the young patient with exertional dyspnea. The objective of this study was to determine the frequency of specific diseases and the most useful tests to establish the diagnosis in an active duty military population presenting with exertional dyspnea.

Methods: A total of 105 active duty military patients with complaints of exertional dyspnea and 69 active duty military asymptomatic controls were evaluated at a pulmonary disease clinic at an Army tertiary care center. All patients and controls underwent a standard evaluation that included history, physical examination, chest radiography (CXR), arterial blood gas testing, laboratory testing, full pulmonary function testing (PFT), inspiratory and expiratory pressure determinations, methacholine challenge testing, cardiopulmonary exercise testing, electrocardiography, and echocardiography.

Results: Obstructive lung disease was found in 52% of patients (35% with exercise-induced asthma and 12% with asthma), 10% had vocal cord dysfunction, and 14% had other diagnoses. Twenty-four percent of patients had no specific diagnosis. Methacholine challenge testing yielded a positive diagnosis in 41% of patients and spirometry in 16%. Other pulmonary tests were of limited value, with abnormal values of 11.4% for full PFT, 2.9% for arterial blood gas testing, and 0.4% for CXR. Laboratory evaluation yielded positive results in less than 5% of patients, and cardiac evaluation was normal in all patients.

Conclusions: Various forms of obstructive lung disease and vocal cord dysfunction were the most common findings in this group. The routine use of spirometry and bronchoprovocation testing is warranted, but other tests, such as full PFT, CXR, and cardiac and laboratory evaluations, have limited diagnostic value in this population.