Occupational lung disease

The role of pathologists in the diagnosis of occupational lung diseases: an expert opinion of the European Society of Pathology Pulmonary Pathology Working Group

Occupational lung/thoracic diseases are a major global public health issue. They comprise a diverse spectrum of health conditions with complex pathology, most of which arise following chronic heavy workplace exposures to various mineral dusts, metal fumes, or following inhaled organic particulate reactions. Many occupational lung diseases could become irreversible; thus accurate diagnosis is mandatory to minimize dust exposure and consequently reduce damage to the respiratory system. Lung biopsy is usually required when exposure history is inconsistent with imaging, in case of unusual or new exposures, in case of unexpected malignancy, and in cases in which there are claims for personal injury and legal compensation. In this paper, we provide an overview of the most frequent occupational lung diseases with a focus on pathological diagnosis. This is a paper that summarizes the expert opinion from a group of European pathologists, together with contributions from other specialists who are crucial for the diagnosis and management of these diseases. Indeed, tight collaboration of all specialists involved in the workup is mandatory as many occupational lung diseases are misdiagnosed or go unrecognized. This document provides a guide for pathologists in practice to facilitate the accurate diagnosis of occupational lung disease. The review article reports relevant topics discussed during an educational course held by expert pathologists, active members of the Pulmonary Pathology Working Group of the European Society of Pathology. The course was endorsed by the University of Padova as a "winter school" (selected project in the call for "Shaping a World-class University" 2022).

Occupational Lung Diseases: Spectrum of Common Imaging Manifestations

Occupational lung diseases (OLD) are a group of preventable conditions caused by noxious inhalation exposure in the workplace. Workers in various industries are at a higher risk of developing OLD. Despite regulations contributing to a decreased incidence, OLD remain among the most frequently diagnosed work-related conditions, contributing to significant morbidity and mortality. A multidisciplinary discussion (MDD) is necessary for a timely diagnosis. Imaging, particularly computed tomography, plays a central role in diagnosing OLD and excluding other inhalational lung diseases. OLD can be broadly classified into fibrotic and non-fibrotic forms. Imaging reflects variable degrees of inflammation and fibrosis involving the airways, parenchyma, and pleura. Common manifestations include classical pneumoconioses, chronic granulomatous diseases (CGD), and small and large airway diseases. Imaging is influenced by the type of inciting exposure. The findings of airway disease may be subtle or solely uncovered upon expiration. High-resolution chest CT, including expiratory-phase imaging, should be performed in all patients with suspected OLD. Radiologists should familiarize themselves with these imaging features to improve diagnostic accuracy.

Interstitial Lung Disease: A Focused Review for the Emergency Clinician

BACKGROUND

Interstitial lung disease (ILD) is a group of restrictive pulmonary diseases associated with diffuse interstitial and parenchymal inflammation. Patients can present to the emergency department with severe exacerbation.

OBJECTIVE

This narrative review provides emergency clinicians with the most recent evidence concerning acute exacerbation of ILD (AE-ILD).

DISCUSSION

AE-ILD can present as acute respiratory distress in a patient with a pre-existing ILD diagnosis or as a de novo presentation of ILD, and is associated with significant morbidity and mortality. A variety of underlying triggers may result in AE-ILD. Emergency clinicians must first assess for extraneous causes of respiratory decompensation prior to diagnosing AE-ILD. For a de novo presentation of ILD, emergency physicians should also assess for possible reversible causes. AE-ILD is managed with systemic steroids, immunosuppressants, intravenous antibiotics, supplemental oxygen, and extracorporeal membrane oxygenation in severe cases. Given the high mortality rates in the absence of lung transplantation, early referral to transplant centers is essential to increase chances of survival.

CONCLUSIONS

Emergency clinician knowledge of AE-ILD can improve the evaluation and management of these patients.

Computational Fluid Dynamics Simulations of Aerosol Behavior in a High Speed (Heubach) Rotating Drum Dustiness Tester

Potential exposure from hazardous dusts may be assessed by evaluating the dustiness of the powders being handled. Dustiness is the tendency of a powder to aerosolize with a given input of energy. We have previously used computational fluid dynamics (CFD) to numerically investigate the flow inside the European Standard (EN15051) Rotating Drum dustiness tester during its operation. The present work extends those CFD studies to the widely used Heubach Rotating Drum. Air flow characteristics are investigated within the Abe-Kondoh-Nagano k-epsilon turbulence model; the aerosol is incorporated via a Euler-Lagrangian multiphase approach. The air flow inside these drums consists of a well-defined axial jet penetrating relatively quiescent air. The spreading of the Heubach jet results in a fraction of the jet recirculating as back-flow along the drum walls; at high rotation rates, the axial jet becomes unstable. This flow behavior qualitatively differs from the stable EN15051 flow pattern. The aerodynamic instability promotes efficient mixing within the Heubach drum, resulting in higher particle capture efficiencies for particle sizes d < 80 μm.

Inhalational lung diseases

The term inhalational lung disease comprises a group of entities that develop secondary to the active aspiration of particles. Most are occupational lung diseases. Inhalational lung diseases are classified as occupational diseases (pneumoconiosis, chemical pneumonitis), hypersensitivity pneumonitis, and electronic-cigarette-associated lung diseases. The radiologic findings often consist of nonspecific interstitial patterns that can be difficult to interpret. Therefore, radiologists' experience and multidisciplinary teamwork are key to ensure correct evaluation. The role of the radiologist is fundamental in preventive measures as well as in diagnosis and management, having an important impact on patients' overall health. It is crucial to take into account patients' possible exposure to particles both at work and at home.

Imaging of Occupational and Environmental Lung Disease

The respiratory tract is continuously exposed to and filters toxins from the home and work environments. Certain occupations and environmental exposures can cause unique injuries to the upper and lower respiratory system. Despite increasing federal regulations in the workplace, occupation-associated lung disease is still a major cause of lung disease and disability and continues to evolve with changes in industry, regulation, and new emerging exposures and toxins. Establishing a diagnosis can be difficult, often due to long latency between exposure and clinical disease, insufficient patient history, and nonspecific or varying imaging appearance. Identifying key imaging features of occupational lung disease along with a multidisciplinary approach can aid in accurate and timely diagnosis. In this review, we will discuss the importance of a comprehensive patient history, multidisciplinary approach to diagnosis, and key imaging features of occupation-related lung injuries. Radiographic and computed tomographic findings will be described and illustrated.

Progressive Massive Fibrosis Mimicking Lung Cancer: Two Case Reports with Potentially Useful CT Features for Differential Diagnosis

Progressive massive fibrosis (PMF) with atypical findings is often misdiagnosed as lung cancer. Atypical features of PMF have been described in some reports; however, these reports only introduced their cases with a short literature review. We report two cases of solitary PMFs with no underlying simple pneumoconiosis or rapid growth at atypical location that were mistaken for lung cancer. We also suggest the useful CT findings to aid in the differential diagnosis.

Non-Infectious Granulomatous Lung Disease: Imaging Findings with Pathologic Correlation

Non-infectious granulomatous lung disease represents a diverse group of disorders characterized by pulmonary opacities associated with granulomatous inflammation, a relatively nonspecific finding commonly encountered by pathologists. Some lesions may present a diagnostic challenge because of nonspecific imaging features; however, recognition of the various imaging manifestations of these disorders in conjunction with patients' clinical history, such as age, symptom onset and duration, immune status, and presence of asthma or cutaneous lesions, is imperative for narrowing the differential diagnosis and determining appropriate management of this rare group of disorders. In this pictorial review, we describe the pathologic findings of various non-infectious granulomatous lung diseases as well as the radiologic features and high-resolution computed tomography imaging features.

Hosseini H, Adeli SH, Wang T. Prevalence of respiratory symptoms and spirometric changes among non-smoker male wood workers

OBJECTIVE

To assess the effects of workplace exposure to hardwood dust on lung function and determine a prevalence of respiratory symptoms among wood workers.

STUDY DESIGN

Cross-sectional observational study.

SETTING

Tertiary referral center.

SUBJECTS AND METHODS

Two hundred seventy-six, non-smoker male wood workers and equal number of non-smoker male office workers, referred to pulmonology clinic included in this study. Evaluation of study participants included completion of a questionnaire regarding respiratory symptoms and baseline spirometry was measured according to the actual recommendations.

RESULTS

Respiratory symptoms including cough, phlegm, chest tightness, and wheezing were significantly higher in wood workers than office workers (40.2% versus 29.3% for cough, p = 0.0073; 40.6% versus 23.6% for phlegm, p<0.0001; 38.0% versus 23.1% for chest tightness, p = 0.0001; 25.3% versus 14.5% for wheezing, p = 0.0014). No statistically significant differences were observed for Dyspnea, and upper respiratory tract symptoms among wood workers compared to office workers. While wood workers were more likely to require spirometry test than office workers (21.4% versus 5.4%, p<0.001) the obstructive changes were more prevalent on spirometry test in wood workers (71.4% obstructive pattern versus 28.6% restrictive pattern). Spirometry test revealed the mean values of FEV1 and FEV1/FVC ratio were significantly lower in the wood workers, compared to their mean values in the control group.

CONCLUSION

Respiratory symptoms associated with work, are more prevalent among wood workers than office workers. Our data revealed that workplace exposure to hardwood dust may compromise respiratory function, indicating the importance and the need for optimizing preventive measures in workplace to protect the respiratory health among exposed workers. Obstructive changes on pulmonary function test is a dominant pathologic pattern in pulmonary function test among wood workers. Further investigation is required by current available tools such as nasal cytology to detect influence of wood dust exposure on the upper respiratory airway.

Respiratory Exposure to Toxic Gases and Metal Fumes Produced by Welding Processes and Pulmonary Function Tests

Background:

Welding is a common industrial process and is harmful to welders' health.

Objective:

To determine the effect of toxic gases and metal fumes produced during 3 welding processes on welders' incidence of respiratory symptoms and pulmonary function.

Methods:

This cross-sectional study was conducted in an Iranian shipbuilding industrial factory in 2018. Using the simple census method, 60 welders were selected as the exposed group. 45 staff members of the administrative unit were also recruited to be served as the control group. Welders' demographic data and respiratory complaints were collected employing a questionnaire. Fumes and gases produced were sampled from the welders' respiratory tract and analyzed by standard methods suggested by the National Institute of Occupational Safety and Health (NIOSH). Pulmonary function test was also performed for each participant.

Results:

The prevalence of respiratory symptoms in all welders was significantly (p<0.05) higher than the control group. The mean FVC, FEV1 and FEV1/FVC measured in welders involved in all 3 processes were significantly lower than those recorded in the control group. The spirometry pattern in welders involved in flux cored arc welding and shielded metal arc welding was obstructive; that in those involved in gas metal arch welding was mixed (obstructive and restrictive pattern).

Conclusion:

Exposure to welding fumes and gases was associated with pulmonary function deterioration. Welders involved in gas metal arch welding had a prevalence of pulmonary disorders compared with those involved in gas metal arch welding and flux cored arc welding.

Costs of isocyanate-related occupational diseases: A systematic review

Although isocyanates are increasingly used in manufacturing and workplace exposure to isocyanates is widely recognized as one of the most frequent causes for occupational lung and skin diseases, little is known about the economic burden on the affected individual and the society. This study provides an overview on costs of occupational diseases related to isocyanates. We performed a systematic literature search of studies in the electronic databases of the German Institute of Medical Documentation and Information, and the Canadian Centre for Occupational Health and Safety. We extracted the key characteristics of the studies and performed a study quality assessment. We identified eight studies on the costs of illness, of which five focused on occupational lung diseases and three on occupational skin diseases. Further, eight studies calculated loss of income/compensation payments. Out of the 16 identified articles, only two reported costs directly attributable to isocyanate-induced diseases (asthma). Studies were hardly comparable because they differed substantially in their methodological approaches. Moreover, the quality assessment of the studies revealed substantial limitations. While a wide range of isocyanate-related costs was identified, consequences of isocyanate-related occupational diseases were considerable in terms of societal costs and loss of income. In most studies, indirect costs were the main cost driver. There is a need for high-quality cost of illness studies on isocyanate-induced diseases stratified by degree of severity and sex. Such studies provide valuable information to develop preventive strategies and set priorities for measures to lower the burden of professional health risks.

Association of respiratory integer and fractional-order models with structural abnormalities in silicosis

BACKGROUND AND OBJECTIVE

Integer and fractional-order models have emerged as powerful methods for obtaining information regarding the anatomical or pathophysiological changes that occur during respiratory diseases. However, the precise interpretation of the model parameters in light of the lung structural changes is not known. This study analyzed the associations of the integer and fractional-order models with structural changes obtained using multidetector computed tomography densitometry (MDCT) and pulmonary function analysis.

METHODS

Integer and fractional-order models were adjusted to data obtained using the forced oscillation technique (FOT). The results obtained in controls (n = 20) were compared with those obtained in patients with silicosis (n = 32), who were submitted to spirometry, body plethysmograph, FOT, diffusing capacity of the lungs for carbon monoxide (DLCO), and MDCT. The diagnostic accuracy was also investigated using ROC analysis.

RESULTS

The observed changes in the integer and fractional-order models were consistent with the pathophysiology of silicosis. The integer-order model showed association only between inertance and the non-aerated compartment (R = -0.69). This parameter also presented the highest associations with spirometry (R = 0.81), plethysmography (-0.61) and pulmonary diffusion (R = 0.53). Considering the fractional-order model, the increase in the poorly aerated and non-aerated regions presented direct correlations with the fractional inertance (R = 0.48), respiratory damping (R = 0.37) and hysteresivity (R = 0.54) and inverse associations with its fractional exponent (R = -0.62) and elastance (-0.35). Significant associations were also observed with spirometry (R = 0.63), plethysmography (0.37) and pulmonary diffusion (R = 0.51). Receiver operator characteristic analysis showed a higher accuracy in the FrOr model (0.908) than the eRIC model (0.789).

CONCLUSIONS

Our study has shown clear associations of the integer and fractional-order parameters with anatomical changes obtained via MDCT and pulmonary function measurements. These findings help to elucidate the physiological interpretation of the integer and fractional-order parameters and provide evidence that these parameters are reflective of the abnormal changes in silicosis. We also observed that the fractional-order model showed smaller curve-fitting errors, which resulted in a higher diagnostic accuracy than that of the eRIC model. Taken together, these results provide strong motivation for further studies exploring the clinical and scientific use of these models in respiratory medicine.

Inflammatory periosteal reaction on ribs associated with lower respiratory tract disease: A method for recording prevalence from sites with differing preservation

Objectives

Inflammatory periosteal reaction (IPR) on the visceral surfaces of the ribs has been used in bioarchaeology as an indicator of lower respiratory tract disease. This article presents a detailed method for recording IPR on the ribs, even those in severely fragmented states, with the objectives of increasing the consistency of recording and producing true prevalence rates for skeletons so as to improve data comparability between future bioarchaeological studies of lower respiratory tract disease.

Materials and methods

The presence and prevalence of respiratory‐related IPR were recorded from three different Sudanese cemetery sites using a detailed method for identifying and recording IPR. Sites with variable preservation were chosen to test the applicability of the method. A flowchart to aid in identification of bony changes is presented. The method requires the recording of IPR on three separate sections of the rib (neck, angle, and shaft) and the allocation of ribs into rib cage regions of upper, upper‐middle, middle, lower‐middle, and lower.

Results

Results demonstrate differences in the distribution of IPR between sites and verify the method's applicability to archeological sites with various levels of skeletal preservation.

Discussion

While crude prevalence rates can indicate the number of individuals experiencing lower respiratory tract disease within a site, this method can provide information about the distribution of IPR within the rib cage. This should lead to new ways of distinguishing respiratory diseases within archeological populations. This method also allows for comparability between well‐preserved and lesser‐preserved sites by accommodating for rib fragmentation.

Outcomes of community-based and home-based pulmonary rehabilitation for pneumoconiosis patients: a retrospective study

Background

Pneumoconiosis patients receive community-based or home-based pulmonary rehabilitation (PR) for symptom management and enhancement of physical and mental well-being. This study aimed to review the clinical benefits of community-based rehabilitation programmes (CBRP) and home-based rehabilitation programmes (HBRP) for PR of pneumoconiosis patients.

Methods

Archival data of pneumoconiosis patients who participated in CBRP and HBRP between 2008 and 2011 was analysed. There were 155 and 26 patients in the CBRP and HBRP respectively. The outcome measures used in the pre- and post-tests were Knowledge, Health Survey Short Form-12 (SF-12), Hospital Anxiety and Depression Scale (HADS), 6-Min Walk Test (6MWT), and Chronic Respiratory Questionnaire (CRQ). Paired t-tests and the Analysis of Covariance (ANCOVA) using the patients’ baseline lung functions as the covariates were performed to examine the changes in the outcomes after completing the programmes. Hierarchical multiple regression analyses were used to examine the relationships between patient’s programme participation factors and different scores of the outcome measures.

Results

After controlling for patients’ baseline lung capacities, significant improvements were revealed among patients participated in CBRP in the scores of the 6MWT, Knowledge, HADS, SF-12 PCS, and CRQ emotion and mastery. The different scores in the Knowledge and HADS were correlated with the patients’ levels of programme participation. In contrast, significant improvements were only found in the scores of the Knowledge and 6MWT among patients who participated in HBRP. The gain scores of the 6MWT were correlated with the patients’ levels of programme participation.

Conclusions

Both CBRP and HBRP benefited patients’ levels of exercise tolerance and knowledge about the disease. CBRP provided greater benefits to patients’ mental and psychosocial needs. In contrast, HBRP was found to improve patients’ physical function, but did not have significant impacts on patients’ mental health and health-related quality of life. The attendance of patients and the participation of their relatives in treatment sessions were important factors in enhancing the positive effects of CBRP and HBRP. These positive outcomes confirm the value of pulmonary rehabilitation programmes for community-dwelling pneumoconiosis patients.

Electronic supplementary material

The online version of this article (10.1186/s12890-018-0692-7) contains supplementary material, which is available to authorized users.

TAK1 inhibition attenuates both inflammation and fibrosis in experimental pneumoconiosis

Pneumoconiosis, caused by inhalation of mineral dusts, is a major occupational disease worldwide. Currently, there are no effective drugs owing to a lack of potential therapeutic targets during either the inflammation or fibrosis molecular events in pneumoconiosis. Here, we performed microarrays to identify aberrantly expressed genes in the above molecular events in vitro and found a hub gene transforming growth factor-β-activated kinase 1 (TAK1), which was highly expressed and activated in pneumoconiosis patients as well as silica-exposed rats with experimental pneumoconiosis. Genetic modulation of TAK1 by CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9, RNA interference and overexpression indicated the important role of TAK1 in both inflammation and fibrosis in experimental pneumoconiosis. To achieve pharmacological TAK1 inhibition, we virtually screened out a natural product resveratrol, which targeted TAK1 at both N161 and A107 residues, and significantly inhibited TAK1 activation to attenuate inflammation and fibrosis in vitro. Consistently, in vivo prevention and intervention studies showed that resveratrol could inhibit pulmonary inflammation and fibrosis in silica-exposed rats.

Lung function in asphalt pavers: a longitudinal study

PURPOSE

To study longitudinal changes in lung function in asphalt pavers and a reference group of road maintenance workers, and to detect possible signs of lung disease by high-resolution computed tomography (HRCT) scans.

METHODS

Seventy-five asphalt pavers and 71 road maintenance workers were followed up with questionnaires and measurements of lung function. Not every worker was tested every year, but most of them had four or more measurement points. The 75 asphalt pavers were also invited to have HRCT scans of the lungs at the end of the follow-up period.

RESULTS

Mean annual decline in forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV₁) of the asphalt pavers was 58 and 35 ml, respectively. Adjusted for age at baseline, packyears of smoking and BMI, the asphalt pavers had a significant excess annual decline in FVC and FEV₁ compared to the references. The screedmen, the most exposed group of the asphalt pavers, showed a significantly larger decline in FVC than the other asphalt pavers (P = 0.029). Fine intralobular fibrosis without evident cysts was identified with HRCT in three subjects (4 %).

CONCLUSION

We conclude that our findings may indicate an excess annual decline in FVC and FEV₁ related to exposure to asphalt fumes. The screedmen, who carry out their work behind and close to the paving machine, had the largest decline in lung function. The finding of adverse pulmonary effects in asphalt pavers calls for better technological solutions to prevent exposure.

Roles of microRNA-146a and microRNA-181b in regulating the secretion of tumor necrosis factor-α and interleukin-1β in silicon dioxide-induced NR8383 rat macrophages

Despite increasing evidence to suggest that microRNA (miR)-146a and miR-181b are involved in the regulation of immune responses and tumor progression, their roles in silicosis remain to be fully elucidated. Therefore, the present study examined the roles of miR-146a and miR-181b in inflammatory responses, and their effect on the expression of the tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) inflammatory chemokines in silicon dioxide (SiO₂)-induced NR8383 rat macrophages. Alterations in the expression levels of miR-146a and miR-181b in rats with silicosis have been previously investigated using miRNA arrays. In the present study, the expression levels of miR-146a and miR-181b were assessed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The NR8383 cells were transfected with miRNA-146a and miR-181b mimics or inhibitors, and the cells and culture supernatants were collected following SiO₂ treatment for 12 h. The expression levels of TNF-α and IL-1β were detected using western blotting, RT-qPCR and ELISA. Analysis of variance and Student's two-tailed t-test were used to perform statistical analyses. The expression level of miR-146a was significantly increased, while the expression level of miR-181b was significantly decreased in the fibrotic lungs of the rats with silicosis, compared with the levels in the normal rats. It was observed that, following treatment of the NR8383 cells with SiO₂ for 12 h, the levels of TNF-α were significantly increased following miR-181b knockdown and the levels of IL-1β were significantly increased following miR-146a knockdown, compared with the inhibitor-treated controls (P<0.05). By contrast, miR-181b mimic transfection led to a significant reduction in the levels of TNF-α (P<0.05), and miR-146a mimics were responsible for the decrease in IL-1β (P<0.05). The results of the present study provide evidence supporting the roles of miR-146a and miR-181b in the pathogenesis of silicosis, and suggest that they may be candidate therapeutic target in this disease.

Role of chest computed tomography in prevention of occupational respiratory disease: review of recent literature

This review provides an update on literature published over the past 5 years that is relevant to using chest computed tomography (CT) as a tool for preventing occupational respiratory disease. An important area of investigation has been in the use of low-dose CT (LDCT) to screen asbestos-exposed populations for lung cancer. Two recent systematic reviews have reached conclusions in support of screening. Based on the limited evidence that is currently available, the Finnish Institute of Occupational Health has recommended LDCT screening in asbestos-exposed individuals if their personal combination of risk factors yields a risk for lung cancer equal to that needed for entry into the National Lung Screening Trial. It has also recommended further research, such as to document the optimal frequency of screening and the effectiveness of screening. Recent literature continues to support high-resolution CT (HRCT) as being more sensitive than chest radiography in detecting pneumoconiosis. However, there are insufficient data to determine the effectiveness of HRCT screening in improving individual outcomes if used in screening for pneumoconiosis and its routine use for this purpose cannot be recommended. However, if HRCT is used to evaluate populations, recent literature shows that the International Classification of HRCT for Occupational and Environmental Respiratory Diseases provides an important tool for reproducible evaluation and recording of findings. HRCT is an important tool for individual patient management and recent literature has documented that chest HRCT findings are significantly associated with outcomes such as pulmonary function and mortality.

Imaging of small airways and emphysema

High-resolution chest computed tomography (CT) is one of the most useful techniques available for imaging bronchiolitis because it shows highly specific direct and indirect imaging signs. The distribution and combination of these various signs can further classify bronchiolitis as either cellular/inflammatory or fibrotic/constrictive. Emphysema is characterized by destruction of the airspaces, and a brief discussion of imaging findings of this class of disease is also included. Typical CT findings include destruction of airspace, attenuated vasculatures, and hyperlucent as well as hyperinflated lungs.

Occupational and environmental lung disease

Occupational and environmental lung disease remains a major cause of respiratory impairment worldwide. Despite regulations, increasing rates of coal worker's pneumoconiosis and progressive massive fibrosis are being reported in the United States. Dust exposures are occurring in new industries, for instance, silica in hydraulic fracking. Nonoccupational environmental lung disease contributes to major respiratory disease, asthma, and COPD. Knowledge of the imaging patterns of occupational and environmental lung disease is critical in diagnosing patients with occult exposures and managing patients with suspected or known exposures.

Relationships between the pulmonary densitometry values obtained by CT and the forced oscillation technique parameters in patients with silicosis

OBJECTIVE

To evaluate the correlations between pulmonary densitometry values and forced oscillation technique (FOT) parameters in patients with silicosis.

METHODS

This cross-sectional study comprised 36 non-smoker patients with silicosis and 20 matched control subjects who were submitted to FOT and multidetector CT (MDCT).

RESULTS

Compared with the control subjects, the MDCT evaluation demonstrated that patients with silicosis exhibited greater total lung mass. These patients also had larger non-aerated and poorly aerated compartments, which included nodules and scarring. Compared with the control subjects, FOT evaluation demonstrated that patients with silicosis exhibited changes in both reactive and resistive properties of the respiratory system. In these patients, there was a greater heterogeneity of the respiratory system and increased work of breathing. Significant correlations between non-aerated compartment size and FOT parameters that reflect the non-homogeneity of the respiratory system were observed. The dynamic compliance of the respiratory system was negatively correlated with non-aerated compartment size, while the impedance at 4 Hz was positively correlated with non-aerated compartment size.

CONCLUSION

Patients with silicosis have heavier lungs. In these patients, a larger non-aerated compartment is associated with a worsening of lung function. A more significant pulmonary involvement is associated with a loss of homogeneity and increased mechanical load of the respiratory system. Advances in knowledge The findings provided by both pulmonary densitometry and FOT may add valuable information to the subjective analysis of silicosis; however, more studies are necessary to evaluate the potential use of these methods for assessing disease progression.

Pulmonary calcifications: a pictorial review and approach to formulating a differential diagnosis

Pulmonary calcifications encompass a wide range of causes, both common and rare, such as calcified pulmonary nodules from chronic fungal infections and pulmonary alveolar microlithiasis. In this pictorial review, we categorize them based on etiology, which includes neoplastic calcifications, nonneoplastic calcified nodules, and iatrogenic- and exposure-related causes of pulmonary calcifications. We also illustrate the most characteristic imaging findings and outline the clinical implications for each of these entities to provide a sensible approach to pulmonary calcifications.

Effects of the six-minute walking test on dyspnea and activities of daily living in pneumoconiosis patients

The purpose of this study was to examine the effects of walking exercise through a 6-min walking test on subjective dyspnea, pulmonary function test, arterial blood gas analysis, and activities of daily living to provide base data for the nursing intervention of pneumoconiosis patients. The subjects were pneumoconiosis patients men aged over 60. This quasi-experimental study was designed with a non-equivalent control group pre- and post-test design, and the study period was September to December 2013. Of the pneumoconiosis inpatient subjects, 39 were assigned to the experimental group and the 39 to the control group. Only the experimental group was subjected to a 6-min walking test three times a week for 10 weeks. Subjective dyspnea was measured based on anxiety about dyspnea during and after the exercise. FEV1% prediction and FEV1/FVC% were used to measure the pulmonary function. The arterial blood gas was measured based on the pH, PaO₂, PaCO₂, and activities of daily living. The data were analyzed through an χ² and t-test. The study results showed that the 6-min walking test reduced the anxiety about dyspnea of the pneumoconiosis patients during the exercise, moderated the dyspnea index after the performance of the activities, and improved the patients’ ability to perform activities of daily living. Thus, walking exercise seems to be an effective nursing intervention to maintain the respiratory rehabilitation outcomes by minimizing the pneumoconiosis patients’ burden.

Imaging in occupational and environmental lung disease

PURPOSE OF REVIEW

Work-related and environmental lung disease is increasing over time and new antigens causing pulmonary response are described in medical literature every year with more or less specific imaging findings. The purposes of this review are to highlight the current role of imaging, describe classic as well as uncommon high-resolution computed tomography (HRCT) patterns helpful in guiding diagnosis and update the recent literature on this topic.

RECENT FINDINGS

Recent literature on imaging of occupational and environmental lung disease is scarce and is predominantly based on the HRCT appearance related to specific antigen exposure and on prognostic significance of findings.

SUMMARY

Knowledge of imaging modality potential and radiologic appearance may guide identification, characterization and follow-up of old and new occupational and environmental lung diseases. HRCT plays a key role in this context, having radiation exposure as a major limitation, especially in asymptomatic patients. Low-dose HRCT has the potential to be employed for screening and surveillance of the exposed individuals. However, future research is needed to further this field.

Pneumoconiosis and respiratory problems in dental laboratory technicians: analysis of 893 dental technicians

OBJECTIVES

To explore the rate of pneumoconiosis in dental technicians (DTP) and to evaluate the risk factors.

MATERIAL AND METHODS

Data of 893 dental technicians, who were admitted to our hospital in the period January 2007-May 2012, from 170 dental laboratories were retrospectively examined. Demographic data, respiratory symptoms, smoking status, work duration, working fields, exposure to sandblasting, physical examination findings, chest radiographs, pulmonary function tests and high-resolution computed tomography results were evaluated.

RESULTS

Dental technicians' pneumoconiosis rate was 10.1% among 893 cases. The disease was more common among males and in those exposed to sandblasting who had 77-fold higher risk of DTP. The highest profusion subcategory was 3/+ (according to the International Labour Organization (ILO) 2011 standards) and the large opacity rate was 13.3%.

CONCLUSIONS

To the best of our knowledge, it was the largest DTP case series (N = 893/90) in the literature in English. Health screenings should be performed regularly for the early diagnosis of pneumoconiosis, which is an important occupational disease for dental technicians.

Farewell to an old friend: chest X-ray vs high-resolution computed tomography in welders' lung disease

INTRODUCTION

Welder's lung disease originated from a mixed exposure to different kinds of metals and chemicals from welding fumes. Because of these various harmful effects, irreversible morphological changes may occur in all parts of the respiratory tract, airways and lung parenchyma. Parenchymal changes are the main lesions that define the severity of exposure. The grade of these lesions is the main criteria for compensation claims and the clinical threshold for the occupational health physician's decision making of work change in order to protect the worker's health. In this study, our aim was to compare the diagnostic performance of chest X-ray (CXR) and high-resolution computed tomography (HRCT) for welders' lung disease.

OBJECTIVES

Seventy-four male welders aged between 25 and 55 years were enrolled to this study.

METHODS

Clinical diagnoses were compared by CXR and HRCT. Same radiologists evaluated the scans without any knowledge about the medical history of the patient (double-blinded evaluation). The agreement between radiologists was compared with Cohen's kappa statistics.

RESULTS

The mean age for 74 welders was 40.7 years. The mean duration of exposure was 18.9 years. Although all were found to be nonpathological on the CXR, 27 mild nodular and nine mild linear opacities, five emphysematous changes, three ground glass infiltrates and one pleural thickening were detected by HRCT.

CONCLUSIONS

HRCT provides better diagnostic performance compared to CXR for the diagnosis of welders' lung disease.

Multiple lung parenchymal abnormalities: Don't panic, let's be pragmatic! The 6 question rule - a checklist strategy

Analysis of multiple lung parenchymal abnormalities on HRCT is a real diagnostic challenge. These abnormalities may be due to a disease of the pulmonary interstitial tissue, the bronchial tree, the cardiovascular system or to abnormal alveolar filling with fluid, blood, cells or tumor, several of these etiologies possibly being concomitant. Systematic pathophysiological reasoning, in the form of a logical checklist, guides reflection and covers many of the most frequent diagnoses and potentially treatable emergencies that can be identified by the non-specialist radiologist. This approach also provides a basis for deepening knowledge of each area. The use of the mnemonic FIBROVAKIM (fibrosis-bronchi-vascular-cancer-infection-medication) is easy to apply and summarizes this strategy.

Oscillation mechanics of the respiratory system in never-smoking patients with silicosis: pathophysiological study and evaluation of diagnostic accuracy

OBJECTIVES

Silicosis is a chronic and incurable occupational disease that can progress even after the cessation of exposure. Recent studies suggest that the forced oscillation technique may help to clarify the changes in lung mechanics resulting from silicosis as well as the detection of these changes. We investigated the effects of airway obstruction in silicosis on respiratory impedance and evaluated the diagnostic efficacy of the forced oscillation technique in these patients.

METHODS

Spirometry was used to classify the airway obstruction, which resulted in four subject categories: controls (n=21), patients with a normal exam (n=12), patients with mild obstruction (n=22), and patients with moderate-to-severe obstruction (n=12). Resistive data were interpreted using the zero-intercept resistance (R0), the resistance at 4 Hz (Rrs4), and the mean resistance. We also analyzed the mean reactance (Xm) and the dynamic compliance. The total mechanical load was evaluated using the absolute value of the respiratory impedance (Z4Hz). The diagnostic potential was evaluated by investigating the area under the receiver operating characteristic curve. ClinicalTrials.gov: NCT01725971.

RESULTS

We observed significant (p<0.0002) increases in R0, Rrs4, Rm, and Z4Hz and significant reductions in Crs,dyn (p<0.0002) and Xm (p<0.0001). R0, Rrs4, Rm, and Z4Hz performed adequately in the diagnosis of mild obstruction (area under the curve>0.80) and highly accurately in the detection of moderate-to-severe obstruction (area under the curve>0.90).

CONCLUSIONS

The forced oscillation technique may contribute to the study of the pathophysiology of silicosis and may improve the treatment offered to these patients, thus representing an alternative and/or complementary tool for evaluating respiratory mechanics.

Statistical modeling of crystalline silica exposure by trade in the construction industry using a database compiled from the literature

A quantitative determinants-of-exposure analysis of respirable crystalline silica (RCS) levels in the construction industry was performed using a database compiled from an extensive literature review. Statistical models were developed to predict work-shift exposure levels by trade. Monte Carlo simulation was used to recreate exposures derived from summarized measurements which were combined with single measurements for analysis. Modeling was performed using Tobit models within a multimodel inference framework, with year, sampling duration, type of environment, project purpose, project type, sampling strategy and use of exposure controls as potential predictors. 1346 RCS measurements were included in the analysis, of which 318 were non-detects and 228 were simulated from summary statistics. The model containing all the variables explained 22% of total variability. Apart from trade, sampling duration, year and strategy were the most influential predictors of RCS levels. The use of exposure controls was associated with an average decrease of 19% in exposure levels compared to none, and increased concentrations were found for industrial, demolition and renovation projects. Predicted geometric means for year 1999 were the highest for drilling rig operators (0.238 mg m(-3)) and tunnel construction workers (0.224 mg m(-3)), while the estimated exceedance fraction of the ACGIH TLV by trade ranged from 47% to 91%. The predicted geometric means in this study indicated important overexposure compared to the TLV. However, the low proportion of variability explained by the models suggests that the construction trade is only a moderate predictor of work-shift exposure levels. The impact of the different tasks performed during a work shift should also be assessed to provide better management and control of RCS exposure levels on construction sites.

Validation of the Forced Oscillation Technique in the diagnostic of respiratory changes in patients with silicosis

Silicosis is a typical occupational respiratory disease characterized by irreversible alterations throughout the alveolar and interstitial structure. The objectives of this study were (1) investigate the potential of the Forced Oscillation Technique (FOT) in the analysis of the patients with silicosis, and (2) evaluate the ability of FOT to identify early alterations in the respiratory mechanics of these patients. Sixty-one volunteers were analyzed: 20 healthy subjects and 41 with silicosis; these, were divided into 4 groups according to spirometric results: normal spirometric exam (n = 11); mild obstruction (n = 20); moderate and severe obstruction (n = 10.). A significant (p〈0.0001) increase in total resistance (R0) and mean resistance (Rm) were observed, as well as a decrease in the dynamic compliance (p〈0.0003) and mean reactance (p〈0.000004). R0 and Rm obtained adequate accuracy for clinical use (>80%). FOT parameters adequately described the pathophysiological changes associated with silicosis and presented adequate accuracy for clinical use, indicating that this technique can be helpful in the evaluation respiratory mechanics in this disease.