Longitudinal changes in lung function following post-9/11 military deployment in symptomatic veterans.

RATIONALE: Exposure to burn pit smoke, desert and combat dust, and diesel exhaust during military deployment to Southwest Asia and Afghanistan (SWA) can cause deployment-related respiratory diseases (DRRDs) and may confer risk for worsening lung function after return. METHODS: Study subjects were SWA-deployed veterans who underwent occupational lung disease evaluation (n = 219). We assessed differences in lung function by deployment exposures and DRRD diagnoses. We used linear mixed models to assess changes in lung function over time. RESULTS: Most symptomatic veterans reported high intensity deployment exposure to diesel exhaust and burn pit particulates but had normal post-deployment spirometry. The most common DRRDs were deployment-related distal lung disease involving small airways (DDLD, 41%), deployment-related asthma (DRA, 13%), or both DRA/DDLD (24%). Those with both DDLD/DRA had the lowest estimated mean spirometry measurements five years following first deployment. Among those with DDLD alone, spirometry measurements declined annually, adjusting for age, sex, height, weight, family history of lung disease, and smoking. In this group, the forced expiratory volume in the first second/forced vital capacity (FEV1/FVC) ratio declined 0.2% per year. Those with more intense inhalational exposure had more abnormal lung function. We found significantly lower estimated FVC and total lung capacity five years following deployment among active duty participants (n = 173) compared to those in the reserves (n = 26). CONCLUSIONS: More intense inhalational exposures were linked with lower post-deployment lung function. Those with distal lung disease (DDLD) experienced significant longitudinal decline in FEV1/FVC ratio, but other DRRD diagnosis groups did not.

First Annual PACT Act Research Symposium on Veterans Health: A Colorado PACT Act Collaboration (CoPAC) Initiative.

In response to the Sergeant First Class Heath Robinson Honoring our Promise to Address Comprehensive Toxics (PACT) Act being signed into law, several research groups in Colorado organized the First Annual PACT Act Research Symposium for Veteran Health. The 2-day symposium was interested in research relevant to military exposures with a primary focus on respiratory and mental health. Information on the PACT Act, data sources in the Department of Veteran Affairs and DOD, and research opportunities at the Veteran Affairs were presented. The morning session centered on respiratory health, highlighting research conducted over the last two decades regarding deployment-related respiratory diseases. Despite the high prevalence of mental health disorders among Veterans, information presented during the afternoon sessions on mental health highlighted the dearth of research to date regarding psychological health and military-related exposures. Policymakers, clinicians, and researchers were encouraged to adopt a life-course approach when conceptualizing physical and psychological exposures. On the second day of meetings, a smaller group of participants discussed next steps in military exposure research, as well as priorities for future research. Per the latter, recommendations for future research were made regarding the need for more precise exposure characterization, longitudinal data collection, and efforts to increase understanding regarding disease pathogenesis, as well as the impact of exposures across multiple organs. Such efforts will require interdisciplinary collaboration.

Sarcoidosis and burn pit exposure in military deployers to Iraq, Afghanistan, and Southwest Asia.

BACKGROUND AND AIM: Inhalational exposures have been hypothesized to play a role in the pathogenesis of sarcoidosis. Herein, we describe a cohort of US Military personnel diagnosed with sarcoidosis during or after deployment to Southwest Asia and Afghanistan, who experienced complex inhalational exposures to burn-pits and desert dust. METHODS: Consecutive military personnel at four sub-specialty clinics across the United States were screened for deployment to Southwest Asia and Afghanistan and diagnosis of sarcoidosis based on 1999 ATS/ERS/WASOG Statement on Sarcoidosis. Detailed demographic, deployment and exposure data was collected. The data combined was analyzed after de-identification and local IRB approval. RESULTS: Twenty-one patients met our case definition. Seventeen patients were male and 62% had extrapulmonary involvement, including 38% with musculoskeletal involvement.  Conclusions: Our study suggests that the sarcoidosis in military personnel to Southwest Asia can be diagnosed many years after deployment. To our knowledge, this is the first case series to describe a group of military personnel diagnosed with sarcoidosis and exposures specific to military deployment to Southwest Asia.

Findings on High Resolution Computed Tomography in Symptomatic Veterans with Deployment-Related Lung Disease.

PURPOSE: Military deployment to dusty, austere environments in Southwest Asia and Afghanistan is associated with symptomatic airways diseases including asthma and bronchiolitis. The utility of chest high-resolution computed tomographic (HRCT) imaging in lung disease diagnosis in this population is poorly understood. We investigated visual assessment of HRCT for identifying deployment-related lung disease compared with healthy controls. MATERIALS AND METHODS: Chest HRCT images from 46 healthy controls and 45 symptomatic deployed military personnel with clinically confirmed asthma and/or biopsy-confirmed distal lung disease were scored by 3 independent thoracic radiologists. We compared demographic and clinical characteristics and frequency of imaging findings between deployers and controls, and between deployers with asthma and those with biopsy-confirmed distal lung disease, using χ2, Fisher exact or t tests, and logistic regression where appropriate. We also analyzed inter-rater agreement for imaging findings. RESULTS: Expiratory air trapping was the only chest CT imaging finding that was significantly more frequent in deployers compared with controls. None of the 24 deployers with biopsy-confirmed bronchiolitis and/or granulomatous pneumonitis had HRCT findings of inspiratory mosaic attenuation or centrilobular nodularity. Only 2 of 21 with biopsy-proven emphysema had emphysema on HRCT. CONCLUSIONS: Compared with surgical lung biopsy, visual assessment of HRCT showed few abnormalities in this small cohort of previously deployed symptomatic veterans with normal or near-normal spirometry.

Deployment-Related Respiratory Disease: Where Are We?

Military personnel and veterans who have deployed to Afghanistan, Iraq, and parts of Southwest Asia (SWA) since 1990 are at risk of developing a host of respiratory symptoms and deployment-related respiratory diseases (DRRDs). This review aims to summarize our current understanding of DRRD and inform pulmonary practitioners of recent updates to DRRD screening, diagnosis, evaluation, and management. The most common respiratory diseases in these patients include asthma, chronic sinonasal disease, laryngeal disease/dysfunction, and distal lung disease. Pulmonary function testing and chest imaging are the most commonly used diagnostic tools, but techniques such as lung clearance index testing via multiple breath washout, forced oscillation testing/impulse oscillometry, and quantitative chest computed tomography (CT) assessment appear promising as noninvasive modalities to aid in lung disease detection in this population. We also summarize guidance on conducting an occupational and deployment exposure history as well as recommendations for testing. Finally, we discuss the Sergeant First Class Heath Robinson Honoring our Promise to Address Comprehensive Toxics Act of 2022 (PACT Act) that includes a list of health conditions that are "presumptively" considered to be related to SWA military deployment toxic exposures, and provide resources for clinicians who evaluate and treat patients with DRRD.

Unexplained dyspnea linked to mitochondrial myopathy following military deployment to Southwest Asia and Afghanistan.

We identified a case of probable mitochondrial myopathy (MM) in a soldier with dyspnea and reduced exercise tolerance through cardiopulmonary exercise testing (CPET) following Southwest Asia (SWA) deployment. Muscle biopsy showed myopathic features. We compared demographic, occupational exposure, and clinical characteristics in symptomatic military deployers with and without probable MM diagnosed by CPET criteria. We evaluated 235 symptomatic military personnel who deployed to SWA and/or Afghanistan between 2010 and 2021. Of these, 168 underwent cycle ergometer maximal CPET with an indwelling arterial line. We defined probable MM based on five CPET criteria: arterial peak exercise lactate >12 mEq/L, anaerobic threshold (AT) ≤50%, maximum oxygen consumption (VO2max ) <95% predicted, oxygen (O2) pulse percent predicted (pp) at least 10% lower than heart rate pp, and elevated ventilatory equivalent for O2 at end exercise (VE/VO2 ≥ 40). We characterized demographics, smoking status/pack-years, spirometry, and deployment exposures, and used descriptive statistics to compare findings in those with and without probable MM. We found 9/168 (5.4%) deployers with probable MM. Compared to symptomatic deployers without probable MM, they were younger (p = 0.0025) and had lower mean BMI (p = 0.02). They had a higher mean forced expiratory volume (FEV1)pp (p = 0.02) and mean arterial oxygen partial pressure (PaO2) at maximum exercise (p = 0.0003). We found no significant differences in smoking status, deployment frequency/duration, or inhalational exposures. Our findings suggest that mitochondrial myopathy may be a cause of dyspnea and reduced exercise tolerance in a subset of previously deployed military personnel. CPET with arterial line may assist with MM diagnosis and management.

Consensus Statements on Deployment-Related Respiratory Disease, Inclusive of Constrictive Bronchiolitis: A Modified Delphi Study.

BACKGROUND: The diagnosis of constrictive bronchiolitis (CB) in previously deployed individuals, and evaluation of respiratory symptoms more broadly, presents considerable challenges, including using consistent histopathologic criteria and clinical assessments. RESEARCH QUESTION: What are the recommended diagnostic workup and associated terminology of respiratory symptoms in previously deployed individuals? STUDY DESIGN AND METHODS: Nineteen experts participated in a three-round modified Delphi study, ranking their level of agreement for each statement with an a priori definition of consensus. Additionally, rank-order voting on the recommended diagnostic approach and terminology was performed. RESULTS: Twenty-five of 28 statements reached consensus, including the definition of CB as a histologic pattern of lung injury that occurs in some previously deployed individuals while recognizing the importance of considering alternative diagnoses. Consensus statements also identified a diagnostic approach for the previously deployed individual with respiratory symptoms, distinguishing assessments best performed at a local or specialty referral center. Also, deployment-related respiratory disease (DRRD) was proposed as a broad term to subsume a wide range of potential syndromes and conditions identified through noninvasive evaluation or when surgical lung biopsy reveals evidence of multicompartmental lung injury that may include CB. INTERPRETATION: Using a modified Delphi technique, consensus statements provide a clinical approach to possible CB in previously deployed individuals. Use of DRRD provides a broad descriptor encompassing a range of postdeployment respiratory findings. Additional follow-up of individuals with DRRD is needed to assess disease progression and to define other features of its natural history, which could inform physicians better and lead to evolution in this nosology.

Postdeployment Respiratory Health: The Roles of the Airborne Hazards and Open Burn Pit Registry and the Post-Deployment Cardiopulmonary Evaluation Network.

Background: Following deployment to the Southwest Asia theater of operations and Afghanistan, many service members and veterans report respiratory symptoms and concerns about their military and environmental exposures. The US Department of Veterans Affairs (VA) established the national Airborne Hazards and Open Burn Pit Registry (AHOBPR) in 2014 to help better understand long-term health conditions that may be related to these exposures. Observations: The AHOBPR provides an online questionnaire and optional health evaluation performed by a primary care or environmental health clinician. The clinical evaluation provides an opportunity for the service member or veteran to talk with a health care professional about their symptoms, exposures, and potential treatment. Data derived from questionnaire responses and health evaluations facilitate medical surveillance and research. The VA also established a network of specialists, referred to as the Post-Deployment Cardiopulmonary Evaluation Network (PDCEN). The PDCEN identifies veterans within the AHOBPR who self-report certain conditions or have unexplained dyspnea and conducts comprehensive diagnostic evaluations. Primary objectives of PDCEN evaluations are to define respiratory and related conditions that are present, determine whether conditions are related to deployment, and work with the veteran's clinician to identify treatments and/or follow-up care to improve their health. We utilize a case example to illustrate the role of the primary care practitioner in connecting veterans to PDCEN clinical evaluations. Conclusions: AHOBPR clinical evaluations represent an initial step to better understand postdeployment health conditions. The PDCEN clinical evaluation extends the AHOBPR evaluation by providing specialty care for certain veterans requiring more comprehensive evaluation while systematically collecting and analyzing clinical data to advance the field.

Small airways and airspace inflammation and injury distinguish lung histopathology in deployed military personnel from healthy and diseased lungs.

The link between military deployment to Southwest Asia and Afghanistan, and the risk for lung disease, including bronchiolitis, is increasingly well-recognized. However, histopathologic features that distinguish deployment-related lung diseases from other diseases affecting the small airways and airspaces are uncertain. A computer-based scoring system was developed to characterize surgical lung biopsy findings in 65 soldiers with persistent respiratory symptoms following military deployment ("deployers"). Deployer lung biopsies were compared to those from 8 patients with chronic hypersensitivity pneumonitis (cHP), 10 with smoking-related respiratory bronchiolitis, 11 with autoimmune or post-transplant obliterative bronchiolitis, and 10 normal donor lungs. Upper, middle, and lower lobe-specific findings in deployer samples were analyzed to inform optimum biopsy location choice for future patients. Surgical lung biopsies from symptomatic deployed military service members were distinguished by a combination of small airways abnormalities including smooth muscle hypertrophy (SMH), peribronchiolar metaplasia (PBM), and lymphocytic inflammation, often with constrictive/obliterative (C/O) and/or respiratory bronchiolitis (43.1%), granulomatous inflammation (38.5%), and moderate/severe emphysema (46.2%, mainly in nonsmokers). Lymphocytic pleural inflammation was common (89.2%), and vascular abnormalities occurred in nearly one-third. Histopathologic features in deployers were most strongly overlapping with cases of cHP, both showing granulomatous inflammation, PBM, and emphysema. SMH along with C/O and respiratory bronchiolitis were common in deployers but not in cHP cases. In deployers, there were significantly higher odds of small airways injury in the lower lobe compared with upper lobe samples.

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.

A 28-Year-Old Man With Chest Pain, Shortness of Breath, and Hemoptysis After Recovery From Coronavirus Disease 2019 Pneumonia.

CASE PRESENTATION: A 28-year-old man presented with shortness of breath, chest pain, and scant hemoptysis. Three weeks previously, he was admitted for coronavirus disease 2019 pneumonia that had been diagnosed by nasal swab polymerase chain reaction. Chest CT imaging demonstrated bilateral ground-glass opacities without evidence of VTE. He was treated with hydroxychloroquine, up to 7 L/min oxygen, and self-proning. After 8 days of hospitalization, he was discharged on 4 L/min oxygen. After discharge, his symptoms and hypoxia resolved.

Multiple breath washout: A noninvasive tool for identifying lung disease in symptomatic military deployers.

RATIONALE: Military deployments to austere environments since November 9, 2001 may put "deployers" at risk for respiratory disease. Sensitive, noninvasive tools for detecting large and small airways injury are needed to identify early disease and help inform management for this at-risk population. OBJECTIVES: We examined multiple breath washout (MBW) as a tool for identifying deployment-related airways disease and assessed host and exposure risk factors compared to healthy controls. METHODS: Between March 2015 and March 2020, 103 healthy controls and 71 symptomatic deployers with asthma and/or distal lung disease completed a questionnaire, spirometry and MBW testing. SAS v. 9.4 was used to compare MBW parameters between deployers and controls via univariate analyses and adjusted for demographic factors using multiple linear regression. MEASUREMENTS AND MAIN RESULTS: Deployers were significantly more likely than controls to have an abnormal lung clearance index (LCI) score indicating global ventilation inhomogeneity. Adjusting for sex, smoking status, smoking pack-years and body mass index, LCI scores were significantly more abnormal among those with deployment-related asthma and distal lung disease compared to controls. The unadjusted variable Sacin (a marker of ventilation inhomogeneity in the acinar airways) was higher and thus more abnormal in those with both proximal and distal airways disease. Deployers who reported more frequent exposure to explosive blasts had significantly higher LCI scores. CONCLUSIONS: This study demonstrates the utility of MBW in evaluating exposure-related airways disease in symptomatic military personnel following deployment to austere environments, and is the first to link exposure to explosive blasts to measurable small airways injury.

Multiple breath washout test data for healthy controls.

This article includes pulmonary function data collected via multiple breath nitrogen washout for 103 healthy U.S. adults recruited at National Jewish Health in Denver, Colorado. Testing was performed by certified technicians and reviewed by expert pulmonologists for quality and consistency. Data were collected from a diverse population that included 52 males and 51 females with an average age of 39 years (range 20-77 years). Participants were of non-Hispanic White (85%), African-American/Black (6%), Hispanic (4%), more than one race (4%) or American Indian/Alaskan Native (1%) race/ethnicity. The majority were never smokers (85%), but 12% were former smokers and 3% were current smokers. Height, weight, and body mass index (BMI) were collected in addition to multiple breath washout (MBW) test parameters such as the lung clearance index (LCI) score.

Silicosis: An Update and Guide for Clinicians.

This overview provides an update on silicosis epidemiology with review of exposures and emerging trends in acute and accelerated silicosis in the twenty-first century. The silicosis epidemics in mining, denim sandblasting, and engineering stone industries are highlighted. Clinical presentations of silicosis and silica-related conditions such as autoimmune, kidney, and mycobacterial disease, as well as lung cancer, are discussed. Important aspects of the new OSHA 2017 Silica Standard are presented. This review also includes practical guidance for clinicians to address questions that may arise when evaluating silica-exposed patients and to the public health responses needed following a diagnosis of silica-related disease.

Respiratory Diseases in Post-9/11 Military Personnel Following Southwest Asia Deployment.

OBJECTIVE: Persistent respiratory symptoms following post-9/11 military deployment to Iraq and Afghanistan are well-recognized, but the spectrum of respiratory diseases remains poorly characterized. This study describes deployment-related respiratory diseases and the diagnostic utility of resting and exercise pulmonary function testing. METHODS: Between 2009 and 2017, 127 consecutive military workers ("deployers") with new-onset respiratory symptoms underwent clinical evaluation. Deployment-related respiratory diseases were classified as proximal and/or distal. Using descriptive statistics and logistic regression, we analyzed lung function parameters associated with deployment-related distal lung disease (DDLD). RESULTS: Common deployment-related respiratory diseases included asthma (31.5%), intermittent laryngeal obstruction (14.2%), rhinosinusitis (15%), and DDLD (68.5%). Decreased diffusion capacity (odds ratio [OR] = 4.6, 95% confidence interval [CI]: 1.4 to 15.1, P = 0.01) was significantly associated with DDLD. CONCLUSIONS: A comprehensive diagnostic approach may identify a spectrum of proximal and distal respiratory diseases that can occur in symptomatic post-9/11 deployers, requiring a personalized approach to care.

Persistent Severe Fixed Airways Obstruction in a High-Dosing E-cigarette User.

Electronic Nicotine Delivery Systems (ENDS), commonly referred to as "e-cigs," were first introduced in the United States in 2007. Since then, their use has grown substantially, with the largest market among adolescents and young adults. ENDS are often perceived by the public as safe alternatives to traditional cigarettes and as aids in smoking cessation. Little is known about inhalational hazards of e-cigs. We describe the case of a 45-year-old man who developed acute respiratory symptoms associated with onset of severe fixed airways obstruction 9 months after he quit traditional cigarettes and began high-dose vaping. Lung biopsy showed respiratory bronchiolitis. Analysis of his heated e-cigarette solution identified a mixture containing vanillin, aldehydes, alcohols and other chemicals, the inhalation effects of which have not been well-studied. This case report adds to the growing literature describing potentially severe lung health effects of vaping and provides a framework for taking a clinical vaping history so that the health consequences of e-cigarettes may be better understood.

Military Occupational Specialty Codes: Utility in Predicting Inhalation Exposures in Post-9/11 Deployers.

OBJECTIVE: The aim of this study was to examine military occupational specialty (MOS) codes to identify those at risk from inhalation exposures during Southwest Asia deployment. METHODS: Exposure intensity to diesel exhaust, sandstorms, burn pit smoke, combat dust, and occupational vapors/dusts/gases/fumes (VDGF) were scored for all Army/Marine MOS codes by an expert panel. Based on MOS code, panel-rated exposure scores were compared with questionnaire data from military personnel with postdeployment respiratory illnesses. RESULTS: All exposures except VDGF were rated higher (range P < 0.0001 to P = 0.003) for combat versus noncombat MOS codes. Deployers with respiratory illnesses reported more intense exposure to diesel exhaust (P < 0.0001), burn pit smoke (P < 0.0001), and sandstorms (P = 0.005) compared with panel raters. These deployers clustered in MOS codes rated highest for inhalation hazard exposure intensity. CONCLUSIONS: MOS codes are useful in identifying high-risk military occupations where medical surveillance and exposure control should be focused.

Respiratory Health after Military Service in Southwest Asia and Afghanistan. An Official American Thoracic Society Workshop Report.

Since 2001, more than 2.7 million U.S. military personnel have been deployed in support of operations in Southwest Asia and Afghanistan. Land-based personnel experienced elevated exposures to particulate matter and other inhalational exposures from multiple sources, including desert dust, burn pit combustion, and other industrial, mobile, or military sources. A workshop conducted at the 2018 American Thoracic Society International Conference had the goals of: 1) identifying key studies assessing postdeployment respiratory health, 2) describing emerging research, and 3) highlighting knowledge gaps. The workshop reviewed epidemiologic studies that demonstrated more frequent encounters for respiratory symptoms postdeployment compared with nondeployers and for airway disease, predominantly asthma, as well as case series describing postdeployment dyspnea, asthma, and a range of other respiratory tract findings. On the basis of particulate matter effects in other populations, it also is possible that deployers experienced reductions in pulmonary function as a result of such exposure. The workshop also gave particular attention to constrictive bronchiolitis, which has been reported in lung biopsies of selected deployers. Workshop participants had heterogeneous views regarding the definition and frequency of constrictive bronchiolitis and other small airway pathologic findings in deployed populations. The workshop concluded that the relationship of airway disease, including constrictive bronchiolitis, to exposures experienced during deployment remains to be better defined. Future clinical and epidemiologic research efforts should address better characterization of deployment exposures; carry out longitudinal assessment of potentially related adverse health conditions, including lung function and other physiologic changes; and use rigorous histologic, exposure, and clinical characterization of patients with respiratory tract abnormalities.