Restrictive spirometry pattern among construction trade workers.

BACKGROUND: Spirometry-based studies of occupational lung disease have mostly focused on obstructive or mixed obstructive/restrictive outcomes. We wanted to determine if restrictive spirometry pattern (RSP) is associated with occupation and increased mortality. METHODS: Study participants included 18,145 workers with demographic and smoking data and repeatable spirometry. The mortality analysis cohort included 15,445 workers with known vital status and cause of death through December 31, 2016. Stratified analyses explored RSP prevalence by demographic and clinical variables and trade. Log-binomial regression models explored RSP risk factors while controlling for important confounders such as smoking, obesity, and comorbidities. Cox regression models explored mortality risk by spirometry category. RESULTS: Prevalence of RSP was very high (28.6%). Mortality hazard ratios for RSP were 1.50 for all causes, 1.86 for cardiovascular diseases, 2.31 for respiratory diseases, and 1.66 for lung cancer. All construction trades except painters, machinists, and roofers had significantly elevated risk for RSP compared to our internal reference group. RSP was significantly associated with both parenchymal and pleural changes seen by chest X-ray. CONCLUSIONS: Construction trade workers are at significantly increased risk for RSP independent of obesity. Individuals with RSP are at increased risk for all-cause mortality as well as mortality attributable to respiratory diseases, cardiovascular diseases, and lung cancer. RSP deserves greater attention in occupational medicine and epidemiology.

Elastomeric half-mask respirator disinfection practices among healthcare personnel.

BACKGROUND: Disposable N95 respirator shortages during the COVID-19 and 2009 H1N1 influenza pandemics highlighted the need for reusable alternatives, such as elastomeric half-mask respirators (EHMRs). Two US medical organizations deployed reusable EHMRs during the COVID-19 response. In addition to wipe-based disinfection following patient care episodes expected per local policies at both organizations, postshift centralized cleaning and disinfection (C&D) was expected at one site (A), permitting shared-pool EHMR use, and optional at the other (Site B), where EHMRs were issued to individuals. Using a survey, we evaluated disinfection practices reported by EHMR users and predictors of disinfection behaviors and perceptions. METHODS: Surveys assessed EHMR disinfection practices, occupational characteristics, EHMR use frequency, training, and individual-issue versus shared-pool EHMR use. RESULTS: Of 1080 EHMR users completing the survey, 76% reported that they disinfect the EHMR after each patient encounter, which was the expected practice at both sites. Increasing EHMR use, recall of disinfection training, and work in intensive care or emergency settings significantly influenced higher reporting of this practice. 36% of respondents reported using centralized C&D, although reporting was higher at the site (A) where this was expected (53%). Confidence in cleanliness of the EHMR following centralized C&D was not influenced by individual versus shared-pool EHMR issue. CONCLUSIONS: Most EHMR users reported adherence with expected post-care individual-based disinfection of EHMRs but did not necessarily use standardized, centralized C&D. Future efforts to limit reliance on behavior related to respirator disinfection may improve EHMR implementation in healthcare to avert dependence on single-use, disposable N95 respirators.

Combined Pulmonary Fibrosis and Emphysema: Pulmonary Function Testing and a Pathophysiology Perspective.

Combined pulmonary fibrosis and emphysema (CPFE) has been increasingly recognized over the past 10-15 years as a clinical entity characterized by rather severe imaging and gas exchange abnormalities, but often only mild impairment in spirometric and lung volume indices. In this review, we explore the gas exchange and mechanical pathophysiologic abnormalities of pulmonary emphysema, pulmonary fibrosis, and combined emphysema and fibrosis with the goal of understanding how individual pathophysiologic observations in emphysema and fibrosis alone may impact clinical observations on pulmonary function testing (PFT) patterns in patients with CPFE. Lung elastance and lung compliance in patients with CPFE are likely intermediate between those of patients with emphysema and fibrosis alone, suggesting a counter-balancing effect of each individual process. The outcome of combined emphysema and fibrosis results in higher lung volumes overall on PFTs compared to patients with pulmonary fibrosis alone, and the forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) ratio in CPFE patients is generally preserved despite the presence of emphysema on chest computed tomography (CT) imaging. Conversely, there appears to be an additive deleterious effect on gas exchange properties of the lungs, reflecting a loss of normally functioning alveolar capillary units and effective surface area available for gas exchange, and manifested by a uniformly observed severe reduction in the diffusing capacity for carbon monoxide (DLCO). Despite normal or only mildly impaired spirometric and lung volume indices, patients with CPFE are often severely functionally impaired with an overall rather poor prognosis. As chest CT imaging continues to be a frequent imaging modality in patients with cardiopulmonary disease, we expect that patients with a combination of pulmonary emphysema and pulmonary fibrosis will continue to be observed. Understanding the pathophysiology of this combined process and the abnormalities that manifest on PFT testing will likely be helpful to clinicians involved with the care of patients with CPFE.

Small airways disease in an Operation Desert Storm Deployer: Case report and review of the literature on respiratory health and inhalational exposures from Gulf War I.

Constrictive Bronchiolitis (CB) has been reported in US Operation Iraqi Freedom/Enduring Freedom (OIF/OEF) deployers but not in those from prior US conflicts. A 62-year old presented with progressive dyspnea 13 years after deployment to the Persian Gulf in 1991-1992, where he was exposed to burning oil well fire emissions, dust storms, and other potential airborne hazards. In 2014, after a chest computed tomography (CT) scan demonstrated diffuse mosaic attenuation, he underwent surgical lung biopsy, which revealed CB. Deployers from both GWI and OIF/OEF share many exposures. As respiratory symptoms are a feature associated with Gulf War medically unexplained illness, there may be a role for renewed interest in evaluating GWI Veterans with unexplained respiratory symptoms for conditions such as CB, which may result from exposures relevant to deployers from both conflicts.

Impulse oscillometry measurement of distal airways obstruction in depleted uranium-exposed Gulf War veterans.

INTRODUCTION: A cohort of Gulf War I veterans who sustained exposure to depleted uranium undergoes biennial surveillance for potential uranium-related health effects. We performed impulse oscillometry and hypothesized that veterans with higher uranium body burdens would have more obstructive abnormalities than those with lower burdens. METHODS: We compared pulmonary function of veterans in high versus low urine uranium groups by evaluating spirometry and oscillometry values. RESULTS: Overall mean spirometry and oscillometry resistance values fell within the normal ranges. There were no significant differences between the high and low uranium groups for any parameters. However, more veterans were classified as having obstruction by oscillometry (42%) than spirometry (8%). CONCLUSIONS: While oscillometry identified more veterans as obstructed, obstruction was not uranium-related. However, the added sensitivity of this method implies a benefit in wider surveillance of exposed cohorts and holds promise in identifying abnormalities in areas of the lung historically described as silent.

Self-reported physician-diagnosed chronic obstructive pulmonary disease and spirometry patterns in Vietnam Era US Army Chemical Corps veterans: A retrospective cohort study.

BACKGROUND: Research on chronic obstructive pulmonary disease (COPD) and herbicide exposure in Vietnam War veterans is limited. METHODS: Survey data were collected from 3193 US Army Chemical Corps veterans on herbicide exposure and self-reported physician-diagnosed COPD. Three spirometric patterns were used to define airflow obstruction (AFO): (i) FEV1 /FVC < 70% ("fixed ratio"); (ii) FEV1 /FVC < lower limit of normal ("LLN"); and (iii) (FEV1 /FVC < LLN and FVC ≥ LLN and FEV1

Update on flavoring-induced lung disease.

PURPOSE OF REVIEW: Since the initial report of bronchiolitis obliterans in microwave popcorn workers, exposures to flavoring substances have been identified in a variety of food and flavor manufacturing facilities and in the consumer market. Attempts to decrease the risk of lung disease have included the use of flavoring substitutes; however, these chemicals may cause similar injury. This article reviews recent flavoring exposures and data on the pathogenesis, clinical characteristics, and surveillance of flavoring-induced lung disease. RECENT FINDINGS: Diacetyl and 2,3-pentanedione exposures have occurred in food production facilities that make cookies, cereal, chocolate, and coffee. Airborne levels often exceed proposed occupational exposure limits. Cases of biopsy-proven bronchiolitis obliterans in heavy popcorn consumers have also been reported. New data demonstrate the presence of diacetyl and 2,3-pentanedione in flavored nicotine liquids used in electronic nicotine delivery systems. SUMMARY: Diacetyl substitutes cause similar peri-bronchiolar fibrotic lesions in animal studies. Their use may continue to place workers at risk for flavoring-induced lung disease, which may present in forms beyond that of fixed airflow obstruction, contributing to delays in identifying and treating patients with flavoring-induced lung disease. Engineering controls, medical surveillance and personal protective equipment can limit flavorings exposure and risk for lung disease.

Evaluation of the patient with an exposure-related disease: the occupational and environmental history.

PURPOSE OF REVIEW: Although the process of taking an occupational and environmental history has remained largely the same, the context in which it is done has changed dramatically over recent years. This review examines the role of the occupational and environmental history in the context of the changing nature of medical practice and discusses methods for evaluating patients with contemporary exposure-related respiratory illnesses. RECENT FINDINGS: Surveillance for occupational lung disease using mnemonic devices, screening questions and the use of structured questionnaires can significantly increase the likelihood and accuracy of detection. Electronic health records likewise can be adapted to include the most important elements of the occupational and environmental history. SUMMARY: The emergence of new technologies and industries will lead to respiratory diseases in novel occupational and environmental contexts. Using the methods described herein can make detecting these diseases easier and less time-consuming.

Experiences when using different EHMR models: Implications for different designs and meeting user expectations.

BACKGROUND: New elastomeric half-mask respirator (EHMR) models without exhalation valves (EVs) or with exhalation valve filters (EVFs) are facilitating expanded use in health settings to reduce workers' exposure to airborne hazards while acting as source control to prevent pathogen spread. The physical comfort of new models has not been assessed in comparison to previously used EHMRs with EVs. METHODS: Researchers assessed 1,962 health care and emergency medical service personnels' self-reported adverse experiences from 2 cohorts while wearing EHMR models with EVs (cohort 1, n = 1,080) and without EVs or with EVFs (cohort 2, n = 882). Fisher exact test identified differences between the cohorts accounting for organizational factors when possible. RESULTS: Cohort 1 respondents experienced communication challenges and discomfort when wearing the EHMR > 1 hour statistically significantly more often than cohort 2. Cohort 2 respondents reported statistically significantly more instances of difficulty breathing, moisture buildup, being uncomfortable to wear < 1 hour, and being uncomfortably warm. CONCLUSIONS: Discomfort is prevalent among end users and more often among those wearing EHMRs without an EV/with an EVF. As EHMR research and development advances, prevalence in use may increase for emergency and routine situations. Organizations may not only need guidance about respirator selection but also model-specific selection.

Performance of Impulse Oscillometry in Identifying Restrictive Lung Defects in a Veteran Cohort.

Background: Impulse oscillometry (IOs) is a technique used to evaluate lung function that uses sound waves imposed over tidal breathing to characterize the airways and lung parenchyma. IOs has been particularly useful in the identification of obstructive lung defects. The present analysis seeks to explore the use of IOs in the identification of restrictive lung physiology among a group of Gulf War I veterans exposed to depleted uranium (DU). Methods: A total of 36 out of a dynamic 85-veteran cohort attended in-person surveillance visits in 2019 and completed both IOs and PFTs. Performance on IOs was evaluated in a cross-sectional analysis of the group overall and in those identified as having restrictive lung defects defined by either spirometry (FEV1/FVC ≥ LLN and FVC < LLN) or lung volumes (TLC < LLN). Results: A total of 6 individuals were identified as having restriction (4 based on spirometry alone and an additional 2 by lung volumes). When restriction was present, IOs values of both resistance and reactance were significantly more abnormal. Conclusion: In the assessment of lung function, IOs may be advantageous over PFTs because it is faster to perform and effort-independent. Although little is known about the utility of IOs in identifying restrictive lung physiology, our results support its use.

Respiratory Health Associated With Systemic Metal Exposure in Post-9/11 Veterans in the Department of Veterans Affairs Toxic Embedded Fragment Registry.

OBJECTIVE: Adverse respiratory outcomes in post-9/11 veterans with elevated urinary metal measures and enrolled in the VA's Toxic Embedded Fragment registry were compared to those without elevated urinary metals. METHODS: Veterans completed questionnaires, underwent pulmonary physiology tests (pulmonary function and oscillometry), and provided urine samples for analysis of 13 metals. Respiratory symptoms, diagnoses, and physiology measures were compared in veterans with ≥1 urine metal elevation to those without metal elevations, adjusted for covariates, including smoking. RESULTS: Among 402 study participants, 24% had elevated urine metals, often just exceeding upper limits of reference values. Compared to veterans without elevated metals, those with elevated metals had had higher FEV 1 values but similar frequencies of respiratory symptoms and diagnoses and abnormalities on pulmonary physiology tests. CONCLUSIONS: Mild systemic metal elevations in post-9/11 veterans are not associated with adverse respiratory health outcomes.

Tolerability, user acceptance and preference for a novel reusable respirator among health care workers.

BACKGROUND: The CleanSpace Technology Halo respirator combines a clear face mask and a powered air supply, without belts or hoses. Although providing higher protection than other respirators used in health care, user acceptance of this device has not been assessed with validated tools. METHODS: We surveyed healthcare workers (HCWs) within a US medical system using Halo respirators in 2021. Subjects completed 3 surveys over 8 weeks, which included the Respirator Comfort, Wearing Experience, and Function Instrument (R-COMFI), a validated tool to assess respirator tolerability. The survey included additional questions about user acceptability and respirator preference. Responses were evaluated for change over time and for significant predictors. RESULTS: Of 113 HCWs who completed the initial survey (29% response rate), mean ± SD R-COMFI score was 9.1± 5.1, (scale 0-47, lower = more tolerable) and did not change over time (P = .42). Fewer years in healthcare significantly predicted better R-COMFI score (P = .01). Many users preferred Halo in both usual care (45%-52%) and care of patients with COVID-19 (60%-64%). DISCUSSION: Halo respirators received favorable tolerability scores by HCWs, who often preferred them, especially during care of patients with COVID-19. CONCLUSIONS: Given demand for respirator use in health care, the innovative design provides higher protection than other respirators with a favorable user experience.

Surface Contamination of Reusable Respirators and Face Shields During Care of Critically Ill COVID-19 Patients.

BACKGROUND: With the emergence of SARS-CoV-2, healthcare workers (HCW) have relied on reusable personal protective equipment (PPE), including respirators and face shields (FSs). The effectiveness of decontamination procedures outside experimental settings is unclear. We examined the prevalence of surface contamination on reusable PPE used by HCWs at a hospital incorporating daily centralized decontamination and post-use wiping by sampling for common pathogens. METHOD: Samples were collected from HCWs' CleanSpace Halo respirator face masks (FMs) and FSs at the start of shift, immediately after use, and after cleaning with disinfecting wipes. Samples were analyzed for pathogens using the Applied Biosystems™ TaqPath™ COVID-19 Combo Kit and ThermoFisher TaqMan Array Card. Patient charts were reviewed for clinical correlation. FINDINGS: Of the 89 samples, 51 from FMs and 38 from FSs, none tested positive for SARS-CoV-2, despite 58 being obtained from PPE used in the care of patients with COVID-19, many with recent aerosol-generating procedures. Four samples tested positive (4.5%) for Staphylococcus aureus, two each from FMs and FSs. FMs that tested positive were not worn concurrently with FSs that tested positive. The FM and FS samples testing positive were worn in the care of patients without diagnosed S. aureus infection. No FMs tested positive following wipe-based disinfection, but both positive FS samples were found after disinfection wiping. CONCLUSION/APPLICATION TO PRACTICE: Contamination of reusable PPE appears uncommon, especially with SARS-CoV-2, when regular decontamination programs are in place. The rare presence of S. aureus highlights the importance of doffing procedures and hand hygiene by HCW to prevent surface contamination.

Economic Impact of Insufficient and Disturbed Sleep in the Workplace.

OBJECTIVE: Insufficient and disturbed sleep are associated with significant morbidity among working-age adults. Poor sleep results in negative health outcomes and increases economic costs to employers. The current systematic review surveyed the peer-reviewed scientific literature and aggregated scientific evidence of sleep-related economic burdens borne by employers. METHODS: A systematic review was performed to identify peer-reviewed, English language studies evaluating the economic impact of insufficient and disturbed sleep among adult employee populations. An exhaustive literature search was performed using keywords related to sleep, economics, and the workplace. Included were scientific studies (randomized controlled trials, cohort and case control studies, cross-sectional and longitudinal studies) examining specific employee populations with relevant sleep and economic outcomes. Each included study was evaluated for risk of bias and relevant data was extracted and summarized. RESULTS: Sleep problems among employee populations are associated with worsened workplace outcomes, such as presenteeism, absenteeism, and accidents. Sleep problems also increased costs to employers, ranging from US$322 to US$1967 per employee. Interventions to improve sleep, such as the use of blue-light filtering glasses, strategic shift scheduling, and targeted interventions to treat insomnia, may improve workplace outcomes and reduce costs. CONCLUSIONS: This review synthesizes the existing data regarding the negative impacts of insufficient and disturbed sleep on the workplace, suggesting that employers have an economic stake in their employees' sleep. TRIAL REGISTRATION: PROSPERO: CRD42021224212.

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.

Physiological Impacts of Surgical Mask Coverage of Elastomeric Half-mask Respirator Exhalation Valves in Healthcare Workers.

OBJECTIVES: Elastomeric half-mask respirator (EHMR) use in healthcare increased significantly during the COVID-19 pandemic. Concern for potential release of infectious aerosols from EHMR exhalation valves prompted recommendations to cover them with surgical masks (SMs), thereby improving source control. The physiological and subjective effects of wearing a SM over the exhalation valve of an EHMR, however, are unknown. METHODS: Twelve healthy healthcare worker volunteers completed a 30-min series of simulated healthcare-related tasks, including resting, talking, walking, and bending, proning and supinating a weighted manikin, and performing cardiopulmonary resuscitation. This series recurred three times with different mask configurations-SM only, EHMR only, or EHMR with SM covering the exhalation valve. A transcutaneous sensor continuously measured carbon dioxide (tcPCO2), oxygen saturation (SpO2), and heart rate (HR) from each subject. Subjects scored their rates of perceived exertion (RPE) and levels of discomfort after each round. Physiological parameters and subjective scores were analyzed using mixed linear models with a fixed effect for mask type, activity, age, body mass index (BMI), and gender. Analysis also tested for interaction between mask type and activity. RESULTS: Physiological parameters remained within normal ranges for all mask configurations but varied by task. Statistically significant but small decreases in mean tcPCO2 (37.17 versus 37.88 mmHg, P < 0.001) and SpO2 (97.74 versus 97.94%, P < 0.001) were associated with wearing EHMR with SM over the exhalation valve compared with EHMR alone. Mean HR did not differ between these mask configurations. Wearing SM only was associated with lower RPE and level of discomfort compared with EHMR, but these subjective scores did not differ when comparing EHMR with SM to EHMR only. Age, BMI, and gender had no significant effect on any outcomes. CONCLUSIONS: Wearing a SM over an EHMR did not produce clinically significant changes in tcPCO2, SpO2, or HR compared with uncovered EHMR during healthcare-related tasks. Covered EHMR use also did not affect perceived exertion or discomfort compared with uncovered EHMR use. Covering the exhalation valve of an EHMR with a SM for source control purposes can be done safely.

Respiratory Protection Perceptions among Malian Health Workers: Insights from the Health Belief Model.

Reusable respiratory protective devices called elastomeric respirators have demonstrated their effectiveness and acceptability in well-resourced healthcare settings. Using standard qualitative research methods, we explored the feasibility of elastomeric respirator use in low- and middle-income countries (LMIC). We conducted interviews and focus groups with a convenience sample of health workers at one clinical center in Mali. Participants were users of elastomeric and/or traditional N95 respirators, their supervisors, and program leaders. Interview transcripts of participants were analyzed using a priori constructs from the Health Belief Model (HBM) and a previous study about healthcare respirator use. In addition to HBM constructs, the team identified two additional constructs impacting uptake of respirator use (system-level factors and cultural factors). Together, these framed the perceptions of Malian health workers and highlighted both facilitators of and barriers to respirator use uptake. As needs for respiratory protection from airborne infectious hazards become more commonly recognized, elastomeric respirators may be a sustainable and economic solution for health worker protection in LMIC.