Bệnh phổi nghề nghiệp

BỆNH PHỔI NGHỀ NGHIỆP GS TS BS Lê Hoàng Ninh Tóm tắt lịch sử y học nghề nghiệp • Thời Cổ đại • Thời trung cổ ( Middle Ages) • Thời Ramazzini (1633-1714) • Thời cách mạng công nghệ ( Industrial Revolution ) • Thời đại mới ( hiện nay) Thời cổ đại • Major economic activities included agriculture, mining for metals, and quarrying. • Pliny the Elder (AD 23-79) recorded the danger to miners from inhalation of fumes and vapors • Because mining was so dangerous, it was considered suitable only for slaves and as punishment for criminals. Thời trung cổ • The Erz Mountains in Bohemia was an important area for the mining and refining of useful and precious metals. A physician named Agricola became the town physician of Joachimsthal. • He recognized that mining activities could lead to conditions that caused chronic shortness of breath. • Agricola was probably observing silicosis and tuberculosis Thời Ramazzini • He published De Morbis Artificum Diatriba in 1700 (Treatise on the Diseases of Workers). He describes: • Dyspnea and metal poisoning in miners • Bronchitis from irritant fumes • Lung fibrosis in potters • Asthma from exposure to corn &flour • Silicosis in stonemasons Ramazzini • “When a doctor visits a working class home he should be content to sit on a three-legged stool, if there isn’t a guilded chair, and he should take time for his examination; and to the questions recommended by Hippocrates, he should add one more – what is your occupation?” Ramazzini • “Medicine, like jurisprudence, should make a contribution to the well-being of workers, and see to it that, so far as possible, they should exercise their callings without harm. So I for my part have done what I could and have not thought it unbecoming to make my way into the lowliest workshops and study the mysteries of the mechanic arts.” Thời Cách Mạng Công Nghệ • Production of steel on an industrial scale. • Increased coal mining to make coke • Fabrics are made in factories from cotton and wool thanks to new machinery. • Charles Turner Thackrah, a town doctor, reported his observations on lung disease in miners and metal grinders and described a new method of measuring lung volume. The Industrial Revolution Continued • Britain institutes Workmen’s Compensation Acts. • As of 1897, injured workers had rights to compensation from compensation from contributions paid by employers. • Silicosis (1919) and Asbestosis (1931) were later recognized and covered. Thời Công Nghệ Mới • E.R.A. Merewether (1892-1970) established the danger of asbestos and promoted the first legislation to control it. • Late 19th century, occupational lung cancers are described in miners. • Allergic alveolitis is described in 1932 • Berylliosis is described in Germany in 1933 • 1970, Congress passes OSHA legislation. Những nguyên lý trong bệnh phổi nghề nghiệp • Industrial processes change and become increasingly complex. • We should anticipate the appearance of a wider range of potentially toxic substances in the air. • It is unlikely that the lung will develop many new ways to react to inhaled substances. • We’ll see old lung diseases with new causes Induction Periods • Ngắn: – Asthma – Infections – Allergic alveolitis – Toxic poisonings • Dài: – Pneumoconioses – Neoplasms Lich sử nghề nghiệp • All jobs held in their lifetime and the duration. • Do symptoms improve with weekends and vacations? • The longer they have had symptoms from occupational asthma, the less clear the connection between symptoms and work • What they did, not their title: – “brusher” drills into hard rock – “caulker” uses electric arc equipment to gouge and fuse metal plates Lịch sử nghề nghiệp • Toxic exposures can produce airway symptoms or an alveolitis. • If everyone in the workplace is affected in a dose-dependent manner, the etiology is likely to be toxic rather than immunologic. • Toxic reactions can occur on the first exposure. Immunologically-mediated diseases require re-exposure Hơi Chất độc • Asphyxiating gases displace oxygen in the alveolus, on the hemoglobin molecule, or prevent oxygen utilization by the cytochrome • Irritants are noticed quickly by the patients and create symptoms proximally to distally. (chlorine and ammonia) • Toxins that attack the alveolar membrane (phosgene and nitrogen dioxide) Suyển/ Hen Nghề Nghiệp • Symptoms usually begin several weeks after exposure begins. • Early in the syndrome, the patient may just notice a dry cough. • Patient may not be continuously exposed to provoking antigen. • A portable peak-flow meter and a diary is very helpful in determining if a work-place antigen is responsible Viêm Phế Quản Xí nghiệp (Industrial Bronchitis ) • Identical symptoms to chronic bronchitis seen with cigarette smoking • Coal workers • Grain Workers • Most non-smokers do not have a decrement in FEV 1.0 Hypersensitivity Pneumonitis • An inflammatory, immunologically mediated response at the alveolar and bronchiolar level to organic particles or gases. • Acute, persistent, and subacute-recurrent forms of the disease. Acute HP • Fever, muscular aches, and malaise 4-8 hours after exposure to the antigen. • May be associated with dry cough or chest tightness. • Shortness of breath is a feature of a severe attack. • Symptoms peak 8-12 hours after exposure and improve over the next 12-24 hours. Persistent HP (acute) • An atypical pneumonia picture with bilateral infiltrates on CXR, hypoxemia, and rales. • May return to hospital within days after “improving” on antibiotics. Recurrent HP • Malaise, dry cough, shortness of breath • Often mistakenly receive multiple courses of antibiotics or psychiatric referral. • Some may progress to pulmonary fibrosis. • In severe cases, CXR, pulmonary functions, and lung biopsy may be indistinguishable from end-stage idipathic pulmonary fibrosis RADS: the Reactive Airways Dysfunction Syndrome • The onset of an asthma like syndrome after a single severe exposure to a respiratory irritant. • Not immunologically mediated • Positive methacholine challenge test • Symptoms of asthma may persist for more than one year after the event. Pneumoconiosis • The term is currently defined by the International Labour Organisation (ILO) as the accumulation of dust in the lungs and the tissue reactions to its presence; tissue reaction may be non-collagenous (minimal stromal reaction) or collagenous (when scarring is permanent. The Pneumoconioses • Asbestosis • Silicosis • Coal Worker’s pneumoconiosis • Berylliosis ILO radiologic classification • Rounded opacities: p (<1.5mm), q, and r (>3 mm) • Irregular opacities: s, t, or u • Profusion: 12 point scale (0/0 thru 3/3) • Grading of pleural thickening Asbestos • A very fibrogenic dust, that causes pulmonary fibrosis • pleural plaques, benign pleural effusions • Mesothelioma, carcinoma of the lung Pleural Reaction - Asbestos Asbestosis • Diffuse fibrosis caused by a persistent alveolar inflammation • Irregular opacities predominately in the lung bases • Rales invariably present • Clubbing is common Asbestos-related pleural plaques Asbestos plaques Gross appearance of Plaque Silicosis Simple Silicosis: small nodules, predominately upper lobes; patient often asymptomatic Complicated Silicosis (Progressive Massive Fibrosis): coalescence into large nodules or masses with retraction of upper lobes Tuberculosis is a common complication Coal Worker’s Pneumoconiosis (CWP) • Coal dust is inert and not particularly fibrogenic. • Can cause industrial bronchitis, emphysema, and progressive massive fibrosis. • Xray looks worse than patient • Many symptomatic coal miners have silicosis or tobacco induced COPD Simple CWP • An asymptomatic patient with normal pulmonary functions. • CXR shows small rounded opacities predominately in the upper lobes. Complications of CWP • Tuberculosis • PMF • Caplan’s Syndrome: a syndrome with rheumatoid arthritis features, PMF, and , usually (>70%), a ppositive rheumatoid factor. Hard Metal Disease • Cobalt is the offending agent • Used in metal cutting or grinding tools and in jet engine turbine blades • Pulmonary fibrosis – probably due to fibrogenic properties of metal • Asthma and hypersensitivity pneumonitis due to metals ability to provoke an immune response (?hapten) Dung Lung • Don’t ask Sick Building Syndrome • Reports began to appear about the time that new, “tighter”, more energy efficient office buildings were built. • Hundreds of organic compounds have been identified in indoor air. • Formaldehyde is an ubiquitous indoor organic that is a mucosal irritant. Multiple Chemical Sensitivity • Mucosal complaints • Asthma like symptoms • Neuro-cognitive complaints Occupational Lung Cancers • Asbestos • Arsenic • Bischloromethyl ether • Coke oven fumes • Insoluble Hexavalent chromium cmpds • Soluble nickel • Mustard gas • Radon daughters Mesothelioma Mesothelioma Small Cell Carcinoma of the Lung • Bischloromethyl ether (BCME) – used as industrial intermediate for organic synthesis, organic solvents, bactericides, fungicides, and cross-linking agents. • Radon Daughters – Radon-222 a decay product of U-238 is a gas and an alpha particle emitter as are its’ decay products: polonium-218,-214, and -210. Present in some metal mines. Legal Aspects of Industrial Disease • “I was never ruined but twice, once when I lost a lawsuit and once when I won.” » Voltaire