Study of Active Duty Military for Pulmonary Disease Related to Environmental Deployment Exposures (STAMPEDE)

Rationale: Because of increased levels of airborne particulate matter in Southwest Asia, deployed military personnel are at risk for developing acute and chronic lung diseases. Increased respiratory symptoms are reported, but limited data exist on reported lung diseases. Objectives: To evaluate new respiratory complaints in military personnel returning from Southwest Asia to determine potential etiologies for symptoms. Methods: Returning military personnel underwent a prospective standardized evaluation for deployment-related respiratory symptoms within 6 months of returning to their duty station. Measurements and Main Results: Prospective standardized evaluation included full pulmonary function testing, high-resolution chest tomography, methacholine challenge testing, and fiberoptic bronchoscopy with bronchoalveolar lavage. Other procedures including lung biopsy were performed if clinically indicated. Fifty patients completed the study procedures. A large percentage (42%) remained undiagnosed, including 12% with normal testing and an isolated increase in lavage neutrophils or lymphocytes. Twenty (40%) patients demonstrated some evidence of airway hyperreactivity to include eight who met asthma criteria and two with findings secondary to gastroesophageal reflux. Four (8%) additional patients had isolated reduced diffusing capacity and the remaining six had other miscellaneous airway disorders. No patients were identified with diffuse parenchymal disease on the basis of computed tomography imaging. A significant number (66%) of this cohort had underlying mental health and sleep disorders. Conclusions: Evaluation of new respiratory symptoms in military personnel after service in Southwest Asia should focus on airway hyperreactivity from exposures to higher levels of ambient particulate matter. These patients may be difficult to diagnose and require close follow-up.