Interstitial lung disease
description
Transcript of Interstitial lung disease
Interstitial lung diseasePaul Swift
What the?
1. Extrinsic Allergic alveolitis2. Idiopathic pulmonary fibrosis3. Industrial dust disease4. Organic dust disease5. Sarcoidosis
What’s important
PathophysiologyClinical features InvestigationManagementPrognosis
Expaaaaand
Pathophysiology Varies: inflammation scarring fibrosis
Presentation Variation on a theme SOBOE, lethargy, dry cough SMOKING, PETS, OCCUPATION
O/E Tachypnoea, clubbing Cyanosis Fine end inspiratory creps
Investigation
Investigations1. Bedside
PEF (work v. home) ABG sats RR
2. Blood FBC, U&Es, LFTs, CRP, ESR ANA and Rf in IPF sometimes
3. Imaging CXR HRCT
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Special tests
Lung function tests Restrictive defect
FVC is reduced FEV1 is reduced in proportion or slightly less FEV1:FVC ratio normal or raised
TLCO the key! Thickened fibrotic alveolar walls shit for gas
transfer
Others: Bronchoscopy, bronchoalveolar lavage
Lung function
Treatment
Conservative Weight loss Increased exercise Smoking cessation
Medical Oxygen Steroids
Surgical Transplant
Extrinsic allergic alveolitis
AKA- hypersensitivty penumonitisType III hypersensitivity reaction
Prior sensitisation to inhaled antigenExamples
1. Mould hay (farmer’s lung)2. Bird faeces (bird fancier’s lung)3. Cotton fibres (byssionosis)4. Sugar can fibres (bagassosis)
Famer’s lung
Bird fancier’s lung
EAA- why, why, why
Clinical features
Standard stuff Cough SOB Fever Malaise
Acute onset hours after exposure More insidious if long-term exposure to small
amounts
O/E: Coarse end inspiratory crackles- upper lung http://www.youtube.com/watch?
v=HTNo_ovhcv8
Investigations
BedsideBloods
Neutrophil & leukocyte count IgG antibody titres
Investigations
Imaging CXR
Often normal in acute form Subacute- reticular nodular Shadowing Chronic- fibrosis with volume loss
HRCT Special
Lung function Bronchoalveolar lavage
Hisolopathological diagnosis
Treatment
Conservative Antigen avoidance!!!!
Medical: ?Corticosteroids Yup, severe disease Speed initial recovery
Prognosis Variable, depends on antigenavoidance
Idiopathic pulmonary fibrosis
AKA- Cryptogenic Fibrosing Alveolitis, Usual Intersitial Pneumonitis
Rare progressive chronic pulmonary fibrosis of unknown aetiology
Peak @ 45-65yrs
IPF- patho
Alveolar walls thickened because of fibrosis Predominantly lower lobes
Number of chronic inflammatory cells in alveoli and interstitium Usual interstitial pneumonitis Other patterns:
Desquamative interstitial pneumonitis Bronchiolitis obliterans
Clinical features
Same old SOB Dry cough Fatigue Can get considerable weight loss
More chronic/late stage Cyanosis Pulmonary hypertension/cor pulmonale Resp failure
Resp failure
On examination
O/E Clubbing
2/3!! Chest expansion reduced Fine-end inspiratory crackles
N/B. Associations
Investigations
Bedside ABG resp failure
Bloods Autoantibodies
ANA +ive in 1/3 Rf +ive in ½
Raised ESR
Investigations
Imaging CXR HRCT
Special Lung function BAL
Neutrophils Transbronchial or open lung biopsy for
histological diagnosis
Treatment Conservative
Stop smoking Weight Exercise
Medical 50% respond to immunosuppression with combo therapy
recommended: Prednisolone 0.5mg/kg 1/12 Azathioprine 2-3mg/kg (can sub in cyclophosphamide for azathioprine)
Oxygen Surgical
Transplant
Prognosis
50% 5 year survival
More dust disease
The pneumoconioses CABS
Coal Worker’s pneumoconiosis Asbestosis Berylliosis Silicosis
Group of disorders due to inhlation of mineral orbiological dusts
Coal Worker’s pneumoconiosis
Dose dependentSimple
Coal dust deposition in the lung Asymptomatic Diagnosis made by several small round opacities
on CXRCaplan’sSevere disease may progress to progressive
massive fibrosis
Progressive massive fibrosis
Large round fibrotic nodules >10mmUpper lobesScarringDyspnoea, cough, sputum
May be black if cavitating lesions
PMF
PMF treatment
Progresses when exposure removed Unlike simple
Prognosis is poor, no treatmentCoal Workers Pneumoconiosis Scheme
Pneumoconiosis Workers’ Compensation Act 1979 Lump sum compensation
Asbestosis
Inhlation of asbestos Plumbers, electricians, builders
Blue asbestos (crocidolite) Can’t be cleared by immune system
Histology: asbestos bodies and features of pulmonary fibrosis, affecting lower lobes more
Rx
No treatmentConsiderable time lag: 20-40 years following
exposureCompensationRisk……….
???
Sarcoidosis
A 25-year old afro-Caribbean woman presents with SOB and bilateral leg lesions……
Multisystem granulomatous disorder of unknown aetiology
Commonly effects the lungs Non-caseating granulomas
Rare (19/100000 in UK)Peak 20-40yrs
Sarcoid path
Non-caseating granulomas (Infiltrated by Th1 lymphocytes and
macrophages) (Fuse to multinucleated epithelioid cells)
Resolution of granulomas 10-20% persistent interstitial fibrosis
Clinical features
90% have pulmonary involvement SOB Chest pain Cough
Non-specific features Lymphadeopathy Weight loss Fever Fatigue
Extrapulmonary features
Inv
Bedside The usual
Bloods FBC (normochronic normocyctic anaemia) ESR Serum Ca2+ Serum ACE
Can be 2x normal levels Used to monitor progression
Imaging- CXR
More inv
Expensive stuff
HRCT Staging Identifying pulmonary fibrosis
Biopsy GOLD standard for diagnosis
Rx
Hilar lymphadenopathy and no pulmonary involvement = no treatment
Medical Infiltration > 6weeks = steroids
Prognosis Depends on stage Mortality < 5% UK Shadowing on CXR >2 years risk pulm
fibrosis
Summary Pathogenesis
Varied but endstage is fibrosis and inflammation of the alveoli and interstitium
Presentation Cough, SOB, fine end inspiratory crackles Smoking, occupation, pets
Investigations Bed, blood, imaging, special Lung function- restrictive CT- honeycombing, groundglass
Treatment Steroids, transplant, avoid exposure
Case study
A 64 year old gentleman presents to his GP with increasing SOB over the last 6 months. His exercise tolerance has reduced to the point where walking to the corner shop makes him out of breath. He also complains of a dry cough. He has a past medical history of high blood pressure which is managed with Ramipril. He has never smoked and works as an office manager. On examination he is slightly short of breath with O2 sats 93% on air and he has clubbing. Auscultation reveals bilateral basal fine end inspiratory crepitations and no wheeze.
????
What are your main differential diagnoses for this gentleman? (make sure these include all important differentials that must be ruled out)
How would you investigate this gentleman?What is your management plan? Will anything
help?Can you tell me about the pathophysiology of
ILD?Can you tell me some causative organisms
for EAA?
Any questions