Clinical Evaluation of Deployed Military Personnel with Chronic Respiratory Symptoms: STAMPEDE (Study of Active Duty Military for Pulmonary Disease Related to Environmental Deployment Exposures) III

Abstract Background Chronic respiratory symptoms are frequently reported after southwest Asia deployment in support of combat operations. The full spectrum of clinical lung diseases related to these deployments is not well characterized. Methods Military personnel with chronic symptoms, primarily exertional dyspnea, underwent a standardized cardiopulmonary evaluation at two tertiary medical centers. Pulmonary function testing consisted of spirometry, lung volumes, diffusing capacity, impulse oscillometry, and bronchodilator testing. Further testing included methacholine challenge, exercise laryngoscopy, high resolution computed tomography, electrocardiogram, and transthoracic echocardiography. Results 380 participants with mean age of 38.5 ± 8.4 years completed testing. Asthma was the most common diagnosis in 87 (22.9%) based on obstructive spirometry/IOS and evidence of airway hyperreactivity, while another 57 (15.0%) patients had reactivity with normal spirometry. Airway disorders included 25 (6.6%) with laryngeal disorders and 16 (4.2%) with excessive dynamic airway collapse. Interstitial lung disease was identified in six patients (1.6%), while 11 patients (2.9%) had fixed obstructive lung disorders. Forty patients (10.5%) had isolated pulmonary function abnormalities and 16 (4.2%) with miscellaneous disorders. The remaining 122 (32.1%) patients with normal studies were classified as undiagnosed exertional dyspnea. Significant co-morbidities identified included elevated body mass index > 30 kg/m2 (34.2%), smoking (36.4%), positive allergy testing (43.7%), sleep apnea (38.5%), and esophageal reflux (13.6%). Mental health disorders and post-traumatic stress disorder were likewise common. Conclusion Post-deployment pulmonary evaluation should focus on common diseases such as asthma and airway hyperreactivity, and include testing for upper airway disorders. Diffuse lung diseases were rarely diagnosed while numerous co-morbidities were common.