Transcript RLDoverview
RESTRICTIVE THORACIC DISEASE Thoracic Restriction due to causes out with the lungs • Skeletal :Vertebrae-eg Thoracic kyphoscoliosis , Ribs – eg Traumatic multiple rib #s • Muscle Weakness - Intercostal or Diaphragmatic (due to Myopathy/Neuropathy/Myelopathy) –eg Myaesthenia Gravis ,Guillan Barre, Motor neurone disease ,Poliomyelitis • Abdominal Obesity/Ascites –compression of thoracic contents • Results in Chronic alveolar under ventilation with low PaO2 ( SaO2) and raised PaCO2 and reduced lung volumes RESTRICTIVE THORACIC DISEASE Due to disease within the lungs –ie Interstitial Lung Disease • Disease of alveolar structures - alveolar walls/lumen ( lung interstitium ) • Pathophysiology impaired alveolar gas exchange - alveolar barrier to O2 exchange (ie Alveolar-Arteriolar barrier ) - CO2 exchange unimpaired as alveolar ventilation normal (CO2 v soluble and blown off ) : PaO2 ( SaO2) normal PaCO2 Aetiology of ILD • Fluid in the alveolar air spaces • Cardiac Po oedema (in alv walls and lumen) due to raised Po venous pressure –ie LVF • Non Cardiac Po oedema –Normal Po venous pressure with leaky Po capillaries due to sepsis or trauma (Shock lung or ARDS)-due to Altitude sickness AETIOLGY OF ILD Consolidation of alveolar air spaces: • Infective pneumonia - viral, bacterial, fungal, protozoal • Infarction - pulmonary emboli/vasculitis • Other causes (ie BOOP) - rheumatoid disease - drugs - cryptogenic AETIOLGY OF ILD Inflam Infiltrate of alveolar walls (ie Alveolitis): •Granulomatous-alveolitis •Extrinsic-Allergic-Alveolitis (Hypersensitivity Pneumonitis-Type 3 reaction) - Farmers lung - Avian (pigeon, budgie) • Sarcoidosis -Multisystem disease -Lymphadenopathy/Erythema nodosum Uveitis/Myocarditis/Neuropathy Aetiology of ILD Alveolitis continued • Drug induced alveolitis - Amiodarone - Bleomycin, Methotrexate - Gold • Fibrosing alveolitis - Rheumatoid , Cryptogenic • Autoimmune(multisystem) -SLE, Polyarteritis,Wegeners,Churg-Strauss AETIOLGY OF ILD Dust-disease (Pneumoconiosis) • Pulmonary fibrosis - asbestosis - silicosis AETIOLGY OF ILD Carcinomatosis • Lymphatic (adenoca) bronchus,breast,prostate,colon,stomach Eosinophilic • Drugs • Fungal • Parasites • Autoimmune vasculitis - Nitrofurantoin - Aspergillosis - Ascaris, Filariasis -Churg-Strauss,Polyarteritis - CLINICAL SYNDROME OF ILD • • • • • Breathless on exertion No cough or wheeze Lung crackles (inspiratory) Finger clubbing Central cyanosis (if hypoxaemic) Pulmonary fibrosis(honeycomb lung) End stage response to any inflammatory process DIAGNOSIS OF ILD #1 • History-eg occupation,drugs,pets,arthritis • Reduced lung volumes : FEV1 FVC1 normal ratio > 75% : Peak flow normal • Reduced gas diffusion (TLCO) • Arterial oxygen desaturation (PaO2 SaO2) - at rest or on exercise DIAGNOSIS OF ILD #2 • Antibodies:Avian,Fungal,Auto-antibodies (Rheumatoid,Antinuclear) • Serum ACE and Ca raised in Sarcoid • Bilateral diffuse alveolar infiltrates on chest X-ray • Echocardiogram to excl LVF • High resolution CT scan-Inflammatory ground glass vs Fibrotic nodular components of alveolar infiltrates • Transbronchial or thoracoscopic lung biopsy -rarely indicated TREATMENT OF ILD • Remove any trigger factor - dust, drug, allergen • Treat any inflammation-immunosuppressives • 1st line Prednisolone • 2nd line Azathioprine Cyclophosphamide Cylcosporin • O2 if hypoxaemic Erythema Nodosum-Sarcoidosis Bilateral hilar lymphadenopathy and lung infiltrares -Sarcoidosis Non caseating granuloma -Sarcoidosis DIP-pre steroids DIP-post steroids Lymphocytic alveolitis and intralumenal macrophages