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Semiquantitative Chest Computed Tomography Assessment Identifies Expiratory Central Airway Collapse in Symptomatic Military Personnel Deployed to Iraq and Afghanistan

PURPOSE

We noted incidental findings on chest computed tomography (CT) imaging of expiratory central airway collapse (ECAC) in dyspneic patients after military deployment to southwest Asia (mainly Iraq and Afghanistan). We developed a standardized chest CT protocol with dynamic expiration to enhance diagnostic reliability and investigated demographic, clinical, and deployment characteristics possibly associated with ECAC.

MATERIALS AND METHODS

We calculated ECAC in 62 consecutive post-9/11 deployers with dyspnea who underwent multi-detector chest CT acquisition. ECAC was defined as ≥70% reduction in the cross-sectional tracheal area at dynamic expiration. We compared demographics (age, smoking, body mass index), comorbid conditions (gastroesophageal reflux, obstructive sleep apnea [OSA]), and clinical findings (air trapping, forced expiratory volume in 1 second percent predicted) in deployers with and without ECAC. We examined associations between ECAC and forced expiratory volume in 1 second percent predicted, air trapping, OSA, deployment duration, and blast exposure.

RESULTS

Among 62 consecutive deployers with persistent dyspnea, 37% had ECAC. Three had severe (>85%) collapse. Those with ECAC were older (mean age 46 vs. 40 y, P=0.02), but no other demographic or clinical characteristics were statistically different among the groups. Although not statistically significant, ECAC odds were 1.5 times higher (95% confidence interval: 0.9, 2.5) for each additional year of southwest Asia deployment. Deployers with ECAC had 1.6 times greater odds (95% confidence interval: 0.5, 4.8) of OSA.

CONCLUSIONS

Findings suggest that ECAC is common in symptomatic southwest Asia deployers. Chest high-resolution CT with dynamic expiration may provide an insight into the causes of dyspnea in this population, although risk factors for ECAC remain to be determined. A standardized semiquantitative approach to CT-based assessment of ECAC should improve reliable diagnosis in dyspneic patients.

Recurrent dyspnea and wheezing- pulmonary function test and dynamic computed tomography may unfold the diagnosis of tracheobronchomalacia

Tracheomalacia patients often present with nonspecific symptoms like cough, wheezing and dyspnea. Tracheomalacia diagnosis is usually attributed to alternative common conditions such as asthma or chronic obstructive lung disease. Certain maneuvers, like forced expiration, or recumbent position may elicit subtle signs of tracheomalacia. Ordering novel pulmonary function testing in sitting upright and supine positions may provide additional clues to suspect tracheomalacia, which can be confirmed by either dynamic chest tomography or bronchoscopy.

Tracheomalacia and recurrent exacerbations of chronic obstructive pulmonary disease: a case report and review of the literature

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of disability and death worldwide. COPD exacerbation is usually treated with antibiotics, systemic corticosteroids, and inhaled bronchodilators. We present a case of recurrent COPD exacerbation that was treated repeatedly with standard therapy. Dynamic expiratory computed tomography of the chest was done, which revealed concomitant tracheomalacia. COPD and tracheomalacia may coexist during recurrent exacerbations of COPD, and delayed diagnosis can be associated with severe comorbidities. Ordering the appropriate imaging may aid in the correct diagnosis and facilitate appropriate management.