Respiratory symptoms and pulmonary physiologic outcomes among post-9/11 veterans with blast exposure

Introduction Among post-9/11 veterans reporting blast exposure from the Veterans Affairs (VA) Toxic Embedded Fragment (TEF) registry, respiratory symptoms are common. Blast injury may cause small airway damage, possibly leading to chronic respiratory pathology. We hypothesized that veterans with blast exposure would have worse pulmonary physiologic testing and be more symptomatic. Materials and methods Veterans enrolled in the VA TEF registry completed study questionnaires assessing blast exposure, history of traumatic brain injury (TBI), and respiratory symptoms and diagnoses. Veterans underwent traditional full pulmonary function testing (PFT) and impulse oscillometry (IOs). Results were compared between blast-exposed and unexposed groups and adjusted for covariates. The impact of blast severity was further assessed using surrogates, such as TBI. Results Among 401 veterans who completed questionnaires, 361 had blast exposure and were more likely to experience dyspnea. Both exposed and unexposed veterans frequently reported respiratory symptoms such as cough, phlegm, and wheeze. Pulmonary physiologic testing was completed in 369 veterans. Veterans with blast exposure had significantly higher FVC, TLC, and DLCO measures, lower FEV1/FVC, but similar IOs results. When TBI was used as a surrogate for more severe blast, veterans reporting TBI had lower TLC, FRC, RV, and RV/TLC ratio. Conclusion Post-9/11 veterans with blast exposure reported more dyspnea but did not have lower lung function values compared to those without. Presence of TBI and blast was associated with lower lung function. Further work is needed to elucidate the mechanism of this association and respiratory impacts of blast injury and TBI.