Deployment-Related Lung Disorders
Her vital signs, physical examination pulmonary function testing with spirometry, lung volumes, and diffusion testing were all normal (Table 4). Bronchial challenge to methacholine demonstrated airways hyperresponsiveness at a PC[-20] FEV1 of 1.25 mg/mL. High-resolution chest CT did not demonstrate air trapping, centrilobular nodules, or other evidence of chronic interstitial lung disease. A cardiopulmonary maximum multistage exercise test with arterial line placement showed normal exercise tolerance with the patient achieving 109% of the maximum predicted workload and 90% of predicted VO2 max.
The patient was diagnosed with deployment-related asthma based on the finding of airways hyperresponsiveness after bronchial challenge testing. Her asthma was considered deployment-related based on the temporal onset of cough and later chest tightness and dyspnea on exertion that occurred during deployment. Ongoing smoking cessation was emphasized.
The patient was started on bronchodilator therapy with albuterol prior to exercise and as needed, but she continued to have symptoms of chest tightness while exercising. Eventually, a low-dose ICS was initiated in conjunction with albuterol as needed. Her symptoms did not resolve with this regimen, but she did experience improvement in exertional chest tightness. This patient was not referred for biopsy given clinical findings of asthma. She will continue pulmonary monitoring every 6 months. However, if her symptoms worsen, she will undergo full PFT, which includes lung volumes and diffusion testing and possible repeat chest imaging.
Conclusion
These 2 cases are representative of the spectrum of deployment-related lung disease. This assessment requires a detailed chronologic occupational and environmental history, establishing a temporal link between respiratory symptoms and deployment exposures and evidence of lung disease on noninvasive testing (or confirmation by surgical lung biopsy in select cases) in which noninvasive testing is nondiagnostic.
Referral for surgical lung biopsy was particularly helpful in the first case, because it ruled out other lung diseases that are more responsive to systemic therapy. However, referral for surgical lung biopsy is not recommended in all patients, and in-depth discussion of the risks and benefits associated with surgery is recommended. Although diagnostic clarity is a benefit of surgical lung biopsy, the authors also discuss with patients that there is no currently available therapy for deployment-related lung disease and thus management is unlikely to change after biopsy. The recommended approach to diagnostic evaluation is shown in Figure 4.
In the authors’ experience, treatment of deployment-related asthma with standard asthma treatment usually improves or stabilizes respiratory symptoms but often does not result in complete resolution of symptoms. Improvement in lung function with systemic pharmacotherapy in the management of deployment-related lung diseases, such as constrictive bronchiolitis, respiratory bronchiolitis, emphysema, or granulomatous pneumonitis has not been observed. Although little is currently known about prognosis, utilization of data collected from the VA Airborne Hazards and Open Burn Pit Registry may contribute to the understanding of deployment exposures and long-term respiratory health effects.
Author disclosures
The authors report no actual or potential conflicts of interest with regard to this article.
Disclaimer
The opinions expressed herein are those of the authors and do not necessarily reflect those of Federal Practitioner, Frontline Medical Communications Inc., the U.S. Government, or any of its agencies. This article may discuss unlabeled or investigational use of certain drugs. Please review complete prescribing information for specific drugs or drug combinations—including indications, contraindications, warnings, and adverse effects—before administering pharmacologic therapy to patients.
