[Update of the AWMF S2k Guideline "Diagnostics and Assessment of Occupational Asbestos-Related Diseases" - What's New?] / Update der AWMF-S2k-Leitlinie "Diagnostik und Begutachtung asbestbedingter Erkrankungen" ­ Was gibt es Neues?

The S2k guideline "Diagnostics and assessment of occupational asbestos-related diseases" was updated in November 2020. This article summarizes the most important changes. There is a new reference to the risk of potentially high exposures to asbestos fibers when renovating plaster, fillers and adhesives containing asbestos.Biomarkers such as mesothelin and calretinin should currently only be used in the context of research. The "asbestos airways disease", which can only be diagnosed histologically, is included in the guideline as an early form of asbestosis. Since the UIP pattern is not characteristic of asbestosis, computed tomography cases with UIP patterns alone cannot be assigned reliably to asbestosis without the simultaneous detection of pleural plaques. With regard to the evaluation of the functional damage, attention is drawn to the importance of flow volume curve, whole-body plethysmography, diffusion capacity and exercise testing. If available, the reference values ​​according to GLI are the basis of the assessment. The guideline contains specific recommendations on prevention, medical treatment and, for the first time, on the importance of outpatient rehabilitation and training therapy. There are also references to the assessment of the new occupational disease ovarian cancer after occupational exposure to asbestos.

Assessment of the biological effects of welding fumes emitted from metal inert gas welding processes of aluminium and zinc-plated materials in humans.

The aim of this study was to investigate biological effects and potential health risks due to two different metal-inert-gas (MIG) welding fumes (MIG welding of aluminium and MIG soldering of zinc coated steel) in healthy humans. In a threefold cross-over design study 12 male subjects were exposed to three different exposure scenarios. Exposures were performed under controlled conditions in the Aachener Workplace Simulation Laboratory (AWSL). On three different days the subjects were either exposed to filtered ambient air, to welding fumes from MIG welding of aluminium, or to fumes from MIG soldering of zinc coated materials. Exposure was performed for 6 h and the average fume concentration was 2.5 mg m(-3). Before, directly after, 1 day after, and 7 days after exposure spirometric and impulse oscillometric measurements were performed, exhaled breath condensate (EBC) was collected and blood samples were taken and analyzed for inflammatory markers. During MIG welding of aluminium high ozone concentrations (up to 250 µg m(-3)) were observed, whereas ozone was negligible for MIG soldering. For MIG soldering, concentrations of high-sensitivity CRP (hsCRP) and factor VIII were significantly increased but remained mostly within the normal range. The concentration of neutrophils increased in tendency. For MIG welding of aluminium, the lung function showed significant decreases in Peak Expiratory Flow (PEF) and Mean Expiratory Flow at 75% vital capacity (MEF 75) 7 days after exposure. The concentration of ristocetin cofactor was increased. The observed increase of hsCRP during MIG-soldering can be understood as an indicator for asymptomatic systemic inflammation probably due to zinc (zinc concentration 1.5 mg m(-3)). The change in lung function observed after MIG welding of aluminium may be attributed to ozone inhalation, although the late response (7 days after exposure) is surprising.

[Pitfalls in diagnostic imaging and assessment of benign asbestos-related thoracic diseases]. / Fallstricke in der radiologischen Diagnostik und Begutachtung der benignen asbestbedingten Erkrankungen des Thorax.

The recognition of asbestos-related diseases of the lung and/or pleura as an occupational disease is of psychosocial, medical and legal importance to the insured person. Radiological imaging is an essential part of the assessment and requires an increasingly high level of competence in the field of radiological diagnosis of pneumoconiosis in interdisciplinary collaboration with occupational medicine and pneumonology. The chest radiogram remains an integral part of basic diagnostic procedures in asbestos-related diseases of the lungs and/or pleura. Its importance lies in the detection of extended pleural changes as well as substantial fibrosis. The inherent low sensitivity and specificity of projection radiography is taken into account by the increasing use of multi-slice high resolution (HR) CT (in low dose technique). Radiological pitfalls in pleural plaque assessment with respect to plain chest X-ray concern all structures that superimpose on the pleural circumference, particularly the anatomical layers of the chest wall (extra-pleural fatty tissue, muscles, thoracic skeleton) as well as other pulmonary findings that can only be reliably assigned using CT. Even if state-of the-art CT is applied, asymmetries and abnormal expression of anatomical structures and variants (e. g. muscles and blood vessels) can lead to false-positive findings. The interstitial fibrosis of asbestosis, manifested as usual interstitial pneumonia (UIP) is non-pathognomonic for asbestosis. Therefore, parietal pleural thickening as a coincident finding to UIP is considered as being the main feature and a highly suggestive indicator of asbestosis in patients with a history of asbestos exposure.

Analysis of quality and feasibility of an objective structured clinical examination (OSCE) in preclinical dental education.

INTRODUCTION: An objective structured clinical examination (OSCE) has been implemented in preclinical dentistry. It was taken at an early stage (propaedeutics course). The objectives of this study were to evaluate the reliability, validity, and feasibility of the examination, and the effect of circuit number on OSCE score. METHODS: The OSCE was designed by an expert committee on the basis of pre-reviewed blueprints and checklists. Eleven stations formed an interdisciplinary circuit. Six groups of students (n = 62) passed sequentially round the same circuit. Statistical analysis was performed by using SPSS. Reliability was determined by measurement of internal consistency (Cronbach's α, Guttman's λ(2) ), standard error of measurement (SEM) (comprising generalisability index α, dependability index ϕ and pass 150;fail reliability p(c) ), consistency coefficient κ, item 150;scale correlation (Pearson correlation), and, because the unidimensionality of the stations could not be assumed, factor analysis including varimax rotation. Convergent validity (Pearson correlation, t-test), and predictive validity for future preclinical courses and the final preclinical examination were assessed by analysis of variance (ANOVA). The effect of the circuit number on score improvement was calculated, including a correction for the general competence of the students (ANOVA). Cost was calculated on the basis of the time invested. RESULTS: Fifty-three out of sixty-two students passed the OSCE (mean score: 67%, SD 7.7, range, 47-81). Scores for each station correlated significantly with total scores (r = 0.35-0.54, P < 0.01). For internal consistency, α = 0.75 (relative SEM 3.8) and λ(2) = 0.766. The dependability index was ϕ = 0.694 (absolute SEM 4.4), p(c) = 0.89 and κ = 0.61. Factor analysis yielded two components: dental-materials-oriented stations and all other stations (explained variance 43%). Scores correlated significantly with success in passing practical tests (i.e. performing dental procedures under examination conditions) (known group validity, P < 0.01) and with scores for subsequent courses and the final preclinical examination (Physikum) (predictive validity, P < 0.001). Later groups performed 4% better on average (CI 95%: 1.2-6.8%; P < 0.01). The cost was 181 Euro per student. CONCLUSIONS: The OSCE is reliable and valid in the context of preclinical dentistry. The cost is substantial. The problem of improvement of students' results with ascending circuit number has to be addressed.

[Medical innovations in the area of conflict between certification and allowance]. / Medizintechnische Innovationen im Spannungsfeld zwischen Zertifizierung und Vergütung.

The medical technology industry is one of the most innovative industries in Germany. Once a medical product is developed, it will be certificated according to European harmonized guidelines and norms. The respective national regulations in Germany are stipulated in the Medical Devices Act (MPG). Part of the certification process is a clinical assessment with the aim to prove that the medical device complies with the so-called essential requirements concerning safety, performance and suitability for the intended use as defined by the manufacturer. A clinical trial may be necessary to establish compliance with these requirements. During this clinical trial the devices are being assessed in patients according to strict requirements by law. The main criticism by the funding agencies is that these trials do not sufficiently apply methods of evidence-based medicine. Thereby they are not useful for assessing the medical benefit of the devices. The manufacturers' counter-argument is that the products are bearing the CE mark, that they comply with the uniform European standards and that their quality therefore has been appropriately assessed. This discussion relates to the question about payment for the products, as according to the Fifth Social Act the funding agencies are only permitted to finance products with a scientifically proven medical benefit. The present article discusses both positions in the context of national and international legislation for the certification of medical devices and presents possible solutions.

[Examples for asbestos-related findings in HRCT - criteria for the assessment of causal relationships in surveillance programmes and medical expert opinion]. / Beispiele asbestfaserstaubbedingter Veränderungen im HRCT - Anhaltspunkte für die Kausalzuordnung bei Vorsorgeuntersuchungen und bei der gutachterlichen Beurteilung.

The increasing use of high-resolution computed tomography in formerly asbestos-exposed workers requires valid diagnostic criteria for the findings which have to be reported as suspicious for being asbestos-related in surveillance programmes and for the assessment of causal relationships between former asbestos exposure and findings in computed tomography. The present article gives examples for asbestos-related findings in HR-CT and discusses the specificity of parenchymal and pleural changes due to asbestos fibres.

[Recommendations for reporting benign asbestos-related findings in chest X-ray and CT to the accident insurances]. / Anzeigekriterien asbestfaserstaubbedingter Erkrankungen gemäss BK-Nr. 4103 BKV.

Asbestos-related diseases still play an important role in occupational medicine. The detection of benign asbestos-related diseases is one condition for the compensation of asbestos-related lung cancer in Germany. Due to the increasing use of computed tomography, asbestos-related diseases are more frequently detected in the early stages. The present article proposes recommendations for the findings which have to be reported as suspicious for being asbestos-related based on a) chest X-rays and b) computed tomography using the International Classification System for Occupational and Environmental Respiratory Diseases (ICOERD).

Longitudinal study on potential neurotoxic effects of aluminium: II. Assessment of exposure and neurobehavioral performance of Al welders in the automobile industry over 4 years.

OBJECTIVES: This is the second of two parallel longitudinal studies investigating Al exposure and neurobehavioral health of Al welders over 4 years. While the first published study in the trail and truck construction industry examined the neurobehavioral development of Al welders from age 41-45 in the group mean (Kiesswetter et al. in Int Arch Occup Environ Health 81:41-67, 2007), the present study in the automobile industry followed the development from 35 to 39. Although no conspicuous neurobehavioral developments were detected in the first study, which furthermore exhibited the higher exposure, it cannot be excluded that exposure effects appear in earlier life and exposure stages. METHODS: The longitudinal study is based on a repeated measurement design comprising 4 years with three measurements in 2 years intervals. 92 male Al welders in the automobile industry were compared with 50 non-exposed construction workers of the same industry and of similar age. The repeated measurements included total dust in air, and Al pre- and post-shift plasma and urine samples. Neurobehavioral methods comprised symptoms, verbal intelligence, logic thinking, psychomotor behavior, memory, and attention. The computer aided tests came from the Motor Performance Series and the European Neurobehavioral Evaluation System. The courses of neurobehavioral changes were analyzed with multivariate covariance-analytical methods considering the covariates age, indicators of 'a priori' intelligence differences (education or markers of 'premorbid' intelligence), and alcohol consumption (carbohydrate-deficient transferrin in plasma). Additionally, the interrelationship, reliability and validity of biomonitoring measures were examined. RESULTS: The mean environmental dust load during welding, 0.5-0.8 mg/m(3), and the mean internal load of the welders (pre-shift: 23-43 microg Al/g creatinine in urine; 5-9 microg Al/l plasma) were significantly lower than in the parallel study. Under low exposure, the stability of biomonitoring measures was reduced, but the Al load differed significantly between Al welders and referents. It could not be shown that the development of neurobehavioral performances over the 4-year period differed between both groups. Mainly, markers of premorbid intelligence and age were related to neurobehavioral performance differences but not Al exposure. CONCLUSIONS: The biomonitoring and neurobehavioral results are in line with the results of the first published study. The repeated measurement models of both studies showed no adverse neurobehavioral effects of Al welding. A modular lifetime-oriented research concept is outlined aiming at the investigation of sequential periods of exposure life with special focus on the biologically most sensitive phases like first exposure and old age.

Computer-assisted diagnosis for early stage pleural mesothelioma: towards automated detection and quantitative assessment of pleural thickening from thoracic CT images.

OBJECTIVES: Pleural thickenings as biomarker of exposure to asbestos may evolve into malignant pleural mesothelioma. For its early stage, pleurectomy with perioperative treatment can reduce morbidity and mortality. The diagnosis is based on a visual investigation of CT images, which is a time-consuming and subjective procedure. Our aim is to develop an automatic image processing approach to detect and quantitatively assess pleural thickenings. METHODS: We first segment the lung areas, and identify the pleural contours. A convexity model is then used together with a Hounsfield unit threshold to detect pleural thickenings. The assessment of the detected pleural thickenings is based on a spline-based model of the healthy pleura. RESULTS: Tests were carried out on 14 data sets from three patients. In all cases, pleural contours were reliably identified, and pleural thickenings detected. PC-based Computation times were 85 min for a data set of 716 slices, 35 min for 401 slices, and 4 min for 75 slices, resulting in an average computation time of about 5.2 s per slice. Visualizations of pleurae and detected thickenings were provided. CONCLUSION: Results obtained so far indicate that our approach is able to assist physicians in the tedious task of finding and quantifying pleural thickenings in CT data. In the next step, our system will undergo an evaluation in a clinical test setting using routine CT data to quantify its performance.

Selection of reference films based on reliability assessment of a classification of high-resolution computed tomography for pneumoconioses.

OBJECTIVE: Worldwide demand has increased for the development of a computed tomography (CT) classification system that supplements the ILO classification of radiographs for pneumoconioses. The authors aimed to show preliminary reliability test results for selected referent films for the CT classification system developed through an international effort by researchers from seven countries. METHODS: Reading trials by eight physicians who have considerable experience in pneumoconioses using a total of 114 lung zones consisting of 6 lung zones of 19 CT films of dust-exposed workers were performed to assess reliability of the classification system by weighted kappa. The results were also utilized for selecting reference films. RESULTS: A good agreement was observed for both first and second reading trials for rounded opacities (weighted kappa=0.76, 0.74, first and second trial results, respectively), irregular opacities (0.60, 0.48), emphysema (0.56, 0.70) and honeycombing (0.72, 0.79). Ground glass opacities, on the other hand, showed moderate agreement (0.43, 0.38). Intra-reader agreements among eight readers were shown in the same table as the mean and standard deviation of weighted kappa statistics. The inter-reader agreement for pleural thickening was not as good as for parenchymal lesions. DISCUSSION: The CT classification development may pioneer noble and sensitive medical screening for dust-exposed workers in selected settings. This system may be applied to radiographic borderline cases of profusion 0/1 and 1/0 by the ILO classification, in a setting that assures the occupational safety and health of workers exposed to some newly developed chemical compounds.

[Structural development of ambulatory surgical care in the United States of America. What can we learn or apply?]. / Strukturelle Entwicklung der ambulanten Chirurgie in den USA Was können wir lernen oder übernehmen?

Expansion of ambulatory surgical care is a major focus in United States health politics. In 1996 a total of 31.5 million ambulatory operations were performed, currently accounting for 45% of yearly procedures. Operations in ophthalmology and gastroenterology are predominant. Ambulatory surgery is organized in different forms: "office-based surgery," "hospital outpatient departments," and "ambulatory surgery centers" (ASC). The numbers of ASCs are rapidly increasing. The current proportion of ASCs is 16% of all operations. The type of ambulatory surgery is primarily defined by payors. Medicare standards are the benchmark for private organizations. Recovery care centers now offer postoperative care beyond the former 23-h threshold. This may lead to a further expanded ASC access. Revenues for ambulatory surgery were so far mostly based on fees for service. The implementation of an outpatient prospective payment system ("OPPS") is planned by Medicare, using fixed package prices within a newly defined ambulatory payment classification ("APC"). The dimension of structural changes could be enormous and possibly be compared with the implementation of DRGs in 1983.

[Documentation of surgical performance--does more really help more? Comparison of the effects of maximum and limited documentation depth of clinical patient data on theoretical revenue volume of a surgical clinic after introduction of the DRG-based reimbursement system]. / Chirurgische Leistungsdokumentation--Hilft viel wirklich viel? Vergleich der Auswirkung von maximaler und geringer Dokumentationstiefe klinischer Patientendaten auf das theoretische Ertragsvolumen einer chirurgischen Klinik nach Einführung des DRG-basierten Entgeltsystems.

INTRODUCTION: The forthcoming introduction of a DRG-based account system in Germany aims at higher transparency and economic efficiency, particularly in the sector of in-patient health care. The availability of documentation of the highest quality, taking into account all potentially relevant diagnoses, appears to be the best method for achieving maximum revenue in individual surgical units. The aim of the study was to determine the relevance of various degrees of documentation depth on calculated DRG-based revenue. Furthermore, we evaluated whether improvements in the quality of documentation can be realized in current hospital organization. METHODS: In a prospective study, clinical data from 402 in-patients were collected and revenues were calculated based on the Australian-Refined DRG system. Various qualities of documentation were defined. In order to find the medical sectors most sensitive to "under-documentation", homogenous cases were classified into 23 treating groups, according to diagnosis. RESULTS: In 267 cases, maximum revenue was determined only by one main diagnosis, while better results could be achieved in 137 cases (34%) by extended documentation quality. Half of this gain could only be achieved by an independent medical documentation specialist. An upper limit of documentation intensity (number of diagnoses) could be defined. Maximum gain did not require maximum number of diagnoses. CONCLUSIONS: Documentation depth has an important influence on the calculated revenue of surgical therapy based on AR-DRG system. The quality and depth of the documentation is not, in itself, sufficient. In order to be really effective, it requires the highest degree of professionalism from hospital staff.

Exposure assessment in the hard metal manufacturing industry with special regard to tungsten and its compounds.

OBJECTIVES: To assess the exposure to tungsten, cobalt, and nickel in a plant producing hard metals. The main components of hard metals are tungsten carbide and cobalt metal. According to recent studies, these two components may be responsible for both fibrogenic and carcinogenic effects. METHODS: 87 workers were investigated (86 male, one female) with a median age of 42 (range 22-58) and a mean duration of exposure of 13 years (range 1-27 years). Stationary and personal air sampling, and biological monitoring were carried out. RESULTS: Ambient monitoring yielded maximum tungsten concentrations of 417 microg/m3 in the production of heavy alloys. A maximum cobalt concentration of 343 microg/m3 and a maximum nickel concentration of 30 microg/m3 were found at the sintering workshop. The highest urinary cobalt concentrations were found in the powder processing department. The mean concentration was 28.5 microg/g creatinine and the maximum value was 228 microg/g creatinine. The maximum nickel concentration in urine of 6.3 microg/g creatinine was detected in the department producing heavy alloys. The highest tungsten concentrations excreted in urine were found in grinders and had a mean value of 94.4 microg/g creatinine and a maximum of 169 microg/g creatinine. Due to the different solubility and bioavailability of the substance, there was no correlation between the tungsten concentrations in air and urine on a group basis. CONCLUSIONS: Despite its low solubility, tungsten carbide is bioavailable. The different bioavailability of tungsten metal and tungsten compounds has to be considered in the interpretation of ambient and biological monitoring data in the hard metal producing industry. The bioavailability increases in the order: tungsten metal, tungsten carbide, tungstenate. Only if both monitoring strategies are considered in combination can a valid and effective definition of high risk groups be derived.

Advances in the surgical treatment of coronary artery disease.

Several new surgical approaches to coronary artery disease revascularization have been developed to avoid the adverse effects associated with conventional coronary bypass graft surgery and the use of cardiopulmonary bypass. This article describes some of these approaches, including minimally invasive direct coronary artery bypass graft surgery, port access surgery, hybrid of integrated coronary revascularization, radial artery and endoscopic vein harvesting, and transmyocardial revascularization. This article also identifies the nursing considerations for each of these surgeries.

[Operational costs and control of performance in surgical clinics between marketing and planning economics. Risk or perhaps quadrature of the circle]. / Betriebswirtschaftliche Kosten- und Leistungsteuerung in chirurgischen Kliniken zwischen Markt- und Planwirtschaft. Riskanter Spagat oder gar Quadratur des Kreises.

Surgical hospitals can be seen as operational or even industrial production systems. Doctors have a major impact on both medical performance and costs. For active participation in the management process, knowledge of industrial controlling mechanisms is required. German hospitals currently receive no procedure-related financial revenues, such as prices or tariffs for defined medical treatment activities. Maximum clinical revenues are, furthermore, limited by principles of planned economy and can be increased only slightly by greater medical performance. Costs are the only target that can be autonomously influenced by the management. Operative controlling in hospitals aims at horizontal and vertical coordination of subunits and decentralization of process regulations. Hospital medical performance is not clearly defined, its quantitative measurement very problematic. Process-orientated clinical activities are not taken into account. A high percentage of hospital costs are fixed and can be influenced only by major structural interventions in the long term. Variable costs are primarily dependent on the quantity of clinical activities, but also heavily influenced by patient structure (comorbidity and risk profile). The various forms of industrial cost calculations, such as internal budgeting, internal markets or flexible plan-cost balancing, cannot be directly applied in hospital management. Based on these analyses, current operational concepts and strategic trends are listed to describe cost-management options in hospitals with focus on the German health reforms.

Assessment of hepatic perfusion in pigs by pharmacokinetic analysis of dynamic MR images.

The purpose of this study was to evaluate a new method based on magnetic resonance imaging for the characterization of hepatic perfusion. In nine pigs dynamic MRI was performed before and after partial occlusion of the portal vein. The pharmacokinetic analysis of the contrast enhancement resulted in a set of parameters (amplitude, A; perfusion rate, kp; elimination rate, kappa(e1); lag time, t(lag)) of which kp was expected to correlate with hepatic perfusion. Reference measurements were done with ultrasound flow-meters and with a thermal diffusion probe (TDP). MR perfusion rate kp significantly dropped under partial portal vein occlusion from an average of 11.3 to 4.9 min(-1) (P < 0.001), while the difference in amplitude A was not significant. The correlation between kp and the TDP measurement was r = 0.89 (P < 0.001). Pharmacokinetic analysis of MRI contrast enhancement provides a non-invasive assessment of hepatic perfusion.