Asbestos-related diseases.

Knowledge of asbestos-related diseases has been accumulating for over one hundred years as the industrial value of asbestos was recognised for the strength of its fibres and their resistance to destruction, resulting in increasing production and use until the multiple health effects have become apparent. Deposition in the lung parenchyma results in an inflammatory/progressively fibrotic response, with impaired gas exchange and reduced lung compliance ('asbestosis'), causing progressive dyspnoea and respiratory failure for which only palliation is indicated, although anti-fibrotic agents used for idiopathic usual interstitial pneumonitis remain to be evaluated. Benign pleural effusion, diffuse pleural fibrosis (occasionally with associated rolled atelectasis) and pleural plaques are the non-malignant pleural diseases that result from fibres reaching the pleura. But the main issues that led to the ban on asbestos in industry are those of malignancy: lung cancer, malignant mesothelioma (MM) of the pleura and MM of the peritoneum. Bronchogenic carcinoma risk from asbestos exposure is dose-dependent and multiplies the risk attributable to tobacco smoking. The principles of treatment are as for all cases of lung cancer. Low-dose computed tomography screening of exposed people can detect early-stage, non-small cell cancers, with improved survival. The amphibole varieties of asbestos are much more potent causes of MM than chrysotile, and the risk increases exponentially for 40-50 years following first exposure. As MM is non-resectable and poorly responsive to chemotherapy and radiotherapy, curative treatment is not possible and screening not justified.

Does this lung nodule need urgent review? A discrete choice experiment of Australian general practitioners.

BACKGROUND: Lung cancer is the leading cause of cancer mortality in Australia. Guidelines suggest that patients with suspected lung cancer on thoracic imaging be referred for urgent specialist review. However, the term "suspected" is broad and includes the common finding of lung nodules, which often require periodic surveillance rather than urgent invasive investigation. The British Thoracic Society recommends that a lung nodule with a PanCan risk > 10% be considered for invasive investigation. This study aimed to assess which factors influence general practitioners (GPs) to request urgent review for a lung nodule and if these factors concur with PanCan risk prediction model variables. METHODS: A discrete choice experiment was developed that produced 32 individual case vignettes. Each vignette contained eight variables, four of which form the parsimonious PanCan risk prediction model. Two additional vignettes were created that addressed haemoptysis with a normal chest computed tomography (CT) scan and isolated mediastinal lymphadenopathy. The survey was distributed to 4160 randomly selected Australian GPs and they were asked if the patients in the vignettes required urgent (less than two weeks) specialist review. Multivariate logistic regression identified factors associated with request for urgent review. RESULTS: Completed surveys were received from 3.7% of participants, providing 152 surveys (1216 case vignettes) for analysis. The factors associated with request for urgent review were nodule spiculation (adj-OR 5.57, 95% CI 3.88-7.99, p < 0.0001), larger nodule size, presentation with haemoptysis (adj-OR 4.79, 95% CI 3.05-7.52, p < 0.0001) or weight loss (adj-OR 4.87, 95% CI 3.13-7.59, p < 0.0001), recommendation for urgent review by the reporting radiologist (adj-OR 4.68, 95% CI 2.86-7.65, p < 0.0001) and female GP gender (adj-OR 1.87, 95% CI 1.36-2.56, p 0.0001). In low risk lung nodules (PanCan risk < 10%), there was significant variability in perceived sense of urgency. Most GPs (83%) felt that a patient with haemoptysis and a normal chest CT scan did not require urgent specialist review but that a patient with isolated mediastinal lymphadenopathy did (75%). CONCLUSION: Future lung cancer investigation pathways may benefit from the addition of a risk prediction model to reduce variations in referral behavior for low risk lung nodules.

Correction to: Does this lung nodule need urgent review? A discrete choice experiment of Australian general practitioners.

Following publication of the original article [1], the authors flagged that the article had gone to publishing with errors in Tables 1-3.

Asbestos exposure and histological subtype of malignant mesothelioma.

BACKGROUND: Malignant mesothelioma (MM) has distinct histological subtypes (epithelioid, sarcomatoid and biphasic) with variable behaviour and prognoses. It is well recognised that survival time varies with the histological subtype of MM. It is not known, however, if asbestos exposure characteristics (type of asbestos, degree of exposure) are associated with different histological subtypes. AIM: To determine if the pathological MM subtype is associated with the type of asbestos or the attributes of asbestos exposure. METHODS: Cases of MM for the period 1962 until 2012, their main histological subtype and their most significant source of asbestos exposure were collected from the Western Australian Mesothelioma Registry. Exposure characteristics included, degree of asbestos exposure (including total days exposed, years since first exposure and, for crocidolite only, calculated cumulative exposure), source of exposure (occupational or environmental), form of asbestos handled (raw or processed) and type of asbestos (crocidolite only or mixed fibres). RESULTS: Patients with the biphasic subtype were more likely to have occupational exposure (OR 1.83, 1.12 to 2.85) and exposure to raw fibres (OR 1.58, 1.19 to 2.10). However, differences between subtypes in the proportions with these different exposure characteristics were small and unlikely to be biologically relevant. Other indicators of asbestos exposure were not associated with the histological subtype of mesothelioma. CONCLUSIONS: There was no strong evidence of a consistent role of asbestos exposure indicators in determining the histological subtype of MM.

Weekend admission and mortality from acute exacerbations of chronic obstructive pulmonary disease in winter.

Historically, acute medical staffing numbers have been lower on weekends and in winter numbers of medical admissions rise. An analysis of acute exacerbations of chronic obstructive pulmonary disease (AECOPD) admissions to Portsmouth Hospitals over a seven-year period was undertaken to examine the effects of admission on a weekend, of winter, and with the opening of a medical admissions unit (MAU). In total, 9,915 admissions with AECOPD were identified. Weekend admissions accounted for 2,071 (20.9%) of cases, winter accounted for 3,026 (30.5%) admissions, and 522 (34.4%) deaths. Adjusted odds ratio (OR) for death on day 1 after winter weekend admission was 2.89 (95% confidence interval (CI) 1.035 to 8.076). After opening the MAU, the OR for death day 1 after weekend winter admission fell from 3.63 (95% CI 1.15 to 11.5) to 1.65 (95% CI 0.14 to 19.01). AECOPD patients have an increased risk of death after admission over a weekend in winter and this effect was reduced by opening a MAU. These findings have implications for the planning of acute care provision in different seasons.

Empyema thoracis: new insights into an old disease.

Pleural infection is a disease of historical importance and is still a modern menace, with incidences rising in adults and children, and a significant mortality in adults. Basic research is hampered by limitations with in vivo models, and the bacteriology of empyema is complex. The role of thoracic ultrasound in guiding investigation and drainage of empyema is clear. Prompt treatment with appropriate systemic antibiotics and chest tube drainage are the key; in cases of failure of these measures, thoracic surgery is of proven efficacy in the treatment of this age-old disease.

Coagulation factors in the airways in moderate and severe asthma and the effect of inhaled steroids.

BACKGROUND: There is evidence of activation of the extrinsic coagulation cascade in the asthmatic airway, and both plasma and locally derived factors may be involved. The hypothesis that the normal haemostatic balance of healthy airways sampled by sputum induction favours fibrin formation in asthmatic airways, and that inhaled corticosteroids (ICS) and plasma exudation influence this balance, was tested. METHODS: ELISA and activity assays were used to measure alpha(2)-macroglobulin (an index of plasma leakage) and coagulation factors in hypertonic saline-induced sputum of 30 stable subjects (10 controls, 10 with moderate asthma and 10 with severe asthma). Additionally, the moderate cohort were weaned off their ICS, followed by further sputum induction 5 days after cessation of steroids. RESULTS: ICS wean induced a significant rise in plasminogen (median (interquartile range (IQR)): 13.92 (6.12-16.17) vs 4.82 (2.14-13.32) ng/ml; 95% CI 0.003 to 8.596, p = 0.0499) and tissue plasminogen activator (tPA; 5.57 (3.57-14.35) vs 3.88 (1.74-4.05) ng/ml; 95% CI 0.828 to 9.972, p = 0.0261) levels in sputum, such that tPA in untreated moderate asthma was significantly (p = 0.0029) higher than normal (2.14 (0.0-2.53) ng/ml). Subjects with severe asthma had significantly more alpha(2)-macroglobulin (p = 0.0003), tissue factor (p = 0.023), plasminogen activator inhibitor (p = 0.0091), thrombin-activatable fibrinolysis inhibitor (p = 0.0031) and fibrin degradation products (p = 0.0293) in their sputum than control subjects. CONCLUSION: Untreated moderate asthma is associated with increased fibrinolysis that is corrected by ICS. Severe asthma and high dose corticosteroid therapy is associated with a profibrinogenic, antifibrinolytic environment in the airways. This study suggests that inhibition of fibrin deposition in severe asthma may be a therapeutic approach.

Asbestos--a legacy and a persistent problem.

Asbestos has been utilised by industrialised nations for over a century and its deleterious health effects have been reported for an almost equal length of time. Whilst developed countries have now reduced their asbestos use, developing nations are increasing their asbestos imports and consumption. Because of this, there is now a perceived risk to Non Government Organisation and military personnel involved in aid operations or conflict areas, where asbestos containing materials and buildings may have been disrupted. With significant asbestos exposures to U.K. military and dockyard personnel in the past, the health consequences are continuing to increase, with the incidence of malignant mesothelioma expected to continue to rise until between 2012-2020. There is no effective cure or treatment for any of the lung or pleural asbestos related diseases; malignant mesothelioma has a median survival of just 6-12 months. Misconceptions about asbestos are widespread, contributed in part by a long latency between exposure and disease. Following diagnosis of an asbestos related disease, financial recompense for ex-service personnel is limited, and the civilian legal implications continue to change. This review will encompass the historical usage of asbestos, its biological effects, the legal and financial implications of exposure, and establish that there may be a continuing threat of exposure to deployed military personnel