Deployment-related Respiratory Issues.

Military deployment to Southwest Asia since 2003 in support of Operations Enduring Freedom/Iraqi Freedom/New Dawn has presented unique challenges from a pulmonary perspective. Various airborne hazards in the deployed environment include suspended geologic dusts, burn pit smoke, vehicle exhaust emissions, industrial air pollution, and isolated exposure incidents. These exposures may give rise to both acute respiratory symptoms and in some instances development of chronic lung disease. While increased respiratory symptoms during deployment are well documented, there is limited data on whether inhalation of airborne particulate matter is causally related to an increase in either common or unique pulmonary diseases. While disease processes such as acute eosinophilic pneumonia and exacerbation of preexisting asthma have been adequately documented, there is significant controversy surrounding the potential effects of deployment exposures and development of rare pulmonary disorders such as constrictive bronchiolitis. The role of smoking and related disorders has yet to be defined. This article presents the current evidence for deployment-related respiratory symptoms and ongoing Department of Defense studies. Further, it also provides general recommendations for evaluating pulmonary health in the deployed military population.

Ebola Virus Disease Simulation Case Series: Patient With Ebola Virus Disease in the Prodromal Phase of Illness (Scenario 1), the "Wet" Gastrointestinal Phase of Illness (Scenario 2), and the Late, Critically Ill Phase of Disease (Scenario 3).

INTRODUCTION: As part of an international response to the Ebola virus disease (EVD) outbreak, the US Department of Defense has deployed thousands of personnel to help train and augment international health care workers. The transmission risk of this deadly virus to health care workers has been extreme, demonstrating the importance of safe practices while caring for these patients. Medical simulation training is well recognized as an integral component for disease outbreak preparedness. Therefore, the US Government created a program of instruction that outlines a formalized EVD training program, using high-fidelity simulation, which projects both an understanding of the disease and its transmission risks. METHODS: Two 5-day training courses were established to provide training to the 65-member Department of Defense Ebola Response Team, which would be activated during a stateside Ebola outbreak. This training consisted of Ebola-specific protocols, personal protective equipment familiarization, and scenario-based certification for physicians, nurses, and public health trainers. Simulation was used to replicate the work environment inside an Ebola treatment unit. RESULTS: Three comprehensive clinical scenarios covering a wide spectrum of EVD presentations were designed around details of published cases to provide the most realistic and relevant EVD training available. The authors conducted 10 iterations of the 3 EVD clinical scenarios totaling more than 1100 hours of simulation training. CONCLUSIONS: Quality practical exercises to include specialized task performance and collective teamwork training relied heavily on dedicated facilities and realistic medical simulation resulting in valuable lessons learned. In future iterations, these characteristics would be imperative to a successful training course.

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.

Prevalence of supranormal pulmonary function test values between a military and nonmilitary cohort.

BACKGROUND: The study objective was to determine differences in the proportion of supranormal pulmonary function tests (PFTs) between active duty (AD) military personnel and a similar non-active duty (non-AD) population. Given the emphasis on cardiovascular fitness in the military, it has been hypothesized that regular exercise in this cohort leads to an increased proportion of supranormal PFTs. We hypothesized that a comparison of PFTs would identify no differences in the ratio of supranormal to normal PFTs between the AD and non-AD populations. METHODS: A retrospective chart review was conducted of all PFT studies at the Brooke Army Medical Center from 2006 to 2011. Studies were included with either an FVC or FEV1 > 110% of predicted, with both values > 100% of predicted. A comparative analysis was performed for patients between 18 and 50 years of age based on AD status. Further analysis was performed on all ages to determine the distribution of supranormal findings in the entire study population. RESULTS: A total of 16,600 interpreted PFTs were queried. Of those, 4,303 (31.6%) were AD patients, and 9,306 (68.4%) were non-AD patients. From all of the PFTs reviewed, a total of 912 (6.7%) were identified as supranormal. When further analyzed, 381 (9.4%) of AD patients 18-50 years old were supranormal, 175 (12.4%) of non-AD patients 18-50 years old were supranormal, and 356 (4.7%) of non-AD patients older than 50 years were supranormal. CONCLUSIONS: This study revealed no significant difference in the proportion of supranormal-to-normal PFTs in an AD versus non-AD duty population of the same age range. Based on these findings, no assumption should be made that supranormal PFTs are more common in military personnel. Interpretation of normal PFTs in AD personnel undergoing evaluation should not differ from that in any typical patient.

Diagnosis and management of chronic lung disease in deployed military personnel.

Military personnel are a unique group of individuals referred to the pulmonary physician for evaluation. Despite accession standards that limit entrance into the military for individuals with various pre-existing lung diseases, the most common disorders found in the general population such as asthma and chronic obstructive pulmonary disease remain frequently diagnosed. Military personnel generally tend to be a more physically fit population who are required to exercise on a regular basis and as such may have earlier presentations of disease than their civilian counterparts. Exertional dyspnea is a common complaint; establishing a diagnosis may be challenging given the subtle nature of symptoms and lack of specificity with pulmonary function testing. The conflicts over the past 10 years in Iraq and Afghanistan have also given rise to new challenges for deployed military. Various respiratory hazards in the deployed environment include suspended geologic dusts, burn pits, vehicle exhaust emissions, industrial air pollution, and isolated exposure incidents and may give rise to both acute respiratory symptoms and chronic lung disease. In the evaluation of deployed military personnel, establishing the presence of actual pulmonary disease and the relationship of existing disease to deployment is an ongoing issue to both military and civilian physicians. This paper reviews the current evidence for chronic lung disease in the deployed military population and addresses any differences in diagnosis and management.

Correlation of airway hyper-responsiveness with obstructive spirometric indices and FEV(1) > 90% of predicted.

BACKGROUND: Current published guidelines on spirometry interpretation suggest an elevated FVC and FEV(1) > 100% of predicted with an obstructive ratio may represent a physiological variant. There is minimal evidence whether this finding can be indicative of symptomatic airways obstruction. METHODS: Pulmonary function testing databases for a 4-year period were retrospectively reviewed. All technically adequate spirometry studies were included, based on these criteria: FEV(1) > 90% of predicted, and FEV(1)/FVC below the lower limit of normal, based on 95th percentile confidence intervals. Clinical indications for testing were noted. Testing for post-bronchodilator response, lung volumes, and methacholine challenge tests were reviewed for evidence of airway hyper-responsiveness (AHR). Comparisons were made between symptomatic versus asymptomatic individuals and FEV(1) values less than or greater than 100% of predicted. RESULTS: A total of 280 studies were analyzed. During their clinical evaluation, 192 patients (69%) had post-bronchodilator spirometry recorded, 63 patients (23%) had lung volumes, and 36 patients (11%) completed methacholine challenge testing. Indications for spirometry included 193 symptomatic patients and 87 asymptomatic patients. Nearly 28% of patients with post-bronchodilator testing met criteria for AHR. No differences in AHR were found between the symptomatic and asymptomatic groups. The majority of patients (77%) with AHR had an FEV(1) < 100%, when compared to patients with an FEV(1) ≥ 100%. CONCLUSIONS: A normal FEV(1) > 90% of predicted with obstructive indices may not represent a normal physiological variant, as 28% of patients were found to have underlying AHR. These findings suggest that clinicians should evaluate for AHR, especially in symptomatic patients, even if the FEV(1) is > 90% of predicted.

Increased airway hyperreactivity with the M40 protective mask in exercise-induced bronchospasm.

OBJECTIVE: Exercise-induced bronchospasm (EIB) has a prevalence of 6% to 7% in United States Army personnel and 3% to 13% in professional athletes. There are reported concerns that military personnel with EIB will have increased airway hyperreactivity or significant dyspnea while wearing the standard military M40 protective mask. The objective of this study is to determine whether the M40 protective gas mask increases airway hyperreactivity in military personnel with exertional dyspnea and the diagnosis of EIB. METHODS: Ten active duty military with EIB (defined as history of exertional dyspnea, normal spirometry, and reactive methacholine challenge test) and 10 normal control subjects were evaluated. Both the participants and control subjects underwent baseline exercise challenge testing (ECT) with and without the M40 protective mask. Forced expiratory volume in one second (FEV1) (percent predicted) post ECT was compared to baseline FEV1 within and between groups along with exercise time. RESULTS: There was no statistical difference in between individuals and between groups wearing the M40 mask. None of the study group had a positive ECT exercising without the M40 mask while 20% of the study group with EIB had a positive ECT wearing the M40 mask. CONCLUSION: Military personnel with EIB who exercised with the M40 protective mask did not overall have significantly increased airway hyperreactivity compared to control subjects. Screening ECT may be beneficial in identifying those susceptible persons who report symptoms while wearing the M40 protective mask.