Respiratory (2) Flashcards

1
Q

Define idiopathic pulmonary fibrosis

A

A chronic, progressive, interstitial restrictive lung disease of an unknown cause which results in fibrosis and thickening of interstitial lung tissue and dyspnoea.

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2
Q

Summarise the aetiology of idiopathic pulmonary fibrosis

A

Unknown cause
Occurs in genetically predisposed patients
Type II pneumocytes overproliferate, causing increased numbers of myofibroblasts which produce collagen in the interstitium

Risk factors:
Age 50-70
Male
Smoking
Occupational dust, metal or wood exposure
GORD
Diabetes
Family history
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3
Q

Summarise the epidemiology of idiopathic pulmonary fibrosis

A

More common in males
More common with increasing age - age at presentation 60-70 years old
Familial form presents younger - 55 to 60 y/o

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4
Q

What are the presenting symptoms of idiopathic pulmonary fibrosis?

A
Progressive symptoms
Dry, non-productive, irritative cough - does not respond to anti-tussives
Dyspnoea on exertion
NO WHEEZE
Weight loss
Fatigue
Malaise
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5
Q

What are the signs on physical examination of idiopathic pulmonary fibrosis?

A

Clubbing
Cyanosis
Dry late-inspiratory bibasilar fine crackles
Signs of right heart failure in advanced disease

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6
Q

What are the appropriate investigations for idiopathic pulmonary fibrosis?

A

CXR:
Usually normal at presentation.
Early disease may show ground glass shadowing.
Late stage disease shows reticulonodular shadowing and signs of cor pulmonale.

High-resolution CT: more sensitive in early disease the an CXR. Reticular opacities, honeycombing, increased thickness of interstitial space

Pulmonary Function Tests: Restrictive features - decreased FEV1, FVC, TLC, lung compliance, normal or increased FEV1/FVC

ANA, anti-CCP and Rheumatoid Factor: 1/3 of patients are positive for ANA or RF

Bronchoalveolar Lavage: exclude infections and malignancy

Lung Biopsy: gold standard for diagnosis BUT may not be appropriate - fibrosis, areas of normal surrouded by scar tissue, honeycombing

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7
Q

Define lung cancer

A

Primary malignant neoplasm of the lungs
Can be small cell or non-small cell

Small cell/oat cell carcinoma - malignant epithelial tumour arising from cells lining the lower respiratory tract

Non-small cell:
Adenocarcinoma
Squamous cell carcinoma
Large cell
Bronchial carcinoid
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8
Q

Summarise the aetiology of lung cancer

A

Small cell carcinoma:
Highly associated with smoking
From small, immature neuroendocrine cells
Aggressive, rapidly metastasising

Adenocarcinoma:
Most common type in female non-smokers

Squamous cell:
Highly associated with smoking

Other risk factors:
FHx
Radon exposure
Asbestos
Air pollution
Ionising radiation
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9
Q

Summarise the epidemiology of lung cancer

A

Adenocarcinoma is most common type in non-smokers
Adenocarcinoma - 35%
Squamous cell carcinoma - 30%
Small cell carcinoma - 30%
Large cell carcinoma - 15%
Non-small cell 3 times more common in men

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10
Q

What are the presenting symptoms of lung cancer?

A

Local symptoms:
Cough
Dyspnoea

Weight loss, fever, fatigue, night sweats

Infiltration into blood vessels - haemoptysis

Symptoms from compression of SVC - facial swelling, dyspnoea
Symptoms from compression of laryngeal nerve - hoarse voice
Symptoms from compression of brachial plexus - pain in shoulder and arm

Small cell:
Symptoms from SIADH
Symptoms of due to ACTH paraneoplastic Cushing’s - weight gain, fatigue
Symptoms of Lambert-Eaton syndrome - weakness which improves with use

Squamous cell carcinoma:
Symptoms of hypercalcaemia due to paraneoplastic PTHrp release - abdominal pain, confusion, bone pain, constipation

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11
Q

What are the signs on physical examination of lung cancer?

A

Wheeze, crackles, reduced breath sounds, dullness to percussion

Weight loss
Horner’s syndrome due to pancoast tumour - miosis, anhydrosis, ptosis
Signs of Cushing’s if paraneoplastic small cell
SVC compression: facial congestion, distension of neck veins, upper limb oedema
Brachial Plexus: wasting of small muscles of hand
Hypertrophic Osteoarthropathy - clubbing, painful swollen wrist/ankles (periosteal new bone formation) - adenocarcinoma

Signs of metastases:
Hepatomegaly
Supraclavicular lymphadenopathy

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12
Q

What are the appropriate investigations for lung cancer?

A

CXR - coin lesion, single or multiple pulmonary nodules, Lobar Collapse, Pleural Effusion, Mediastinal or Hilar Fullness
Small cell and squamous cell likely central mass

CT chest, liver, adrenals - non-calcified nodule, useful for staging
Bronchoscopy and biopsy
Sputum cytology - malignant cells

FBC - may show anaemia
U&E’s - elevated calcium due to PTHrp paraneoplastic squamous cell carcinoma
LFTS (normal/elevated if lone, increased ALP in bone metastases)
Isotope bone scans

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13
Q

Define extrinsic allergic alveolitis

A

An excessive immune response to inhaled antigens, usually from occupational exposures to organic dusts, leading to inflammation of the alveoli and distal bronchioles.

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14
Q

Summarise the aetiology of extrinsic allergic alveolitis

A

Inhalation of antigenic dusts (microbes, animal proteins) induce a hypersensitivity response in susceptible individuals

Farmer’s lung - inhalation of thermophilic actinomycetes from damp, moudly hay
Pigeon fancier’s lung - inhalation of bird poo and feathers
Malt worker’s lung - mouldy barley containing aspergillus
Exposure to inhalation of actinomycetes from mouldy sugar cane
Humidifier lung: water containing bacteria and Naegleria (amoeba)

Risk Factors:
Smoking
Viral infection
Exposure to: avian protein, mould and bacterial antigen

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15
Q

Summarise the epidemiology of extrinsic allergic alveolitis

A

UNCOMMON (2% occupational lung disease)
50% reported cases affect farm workers
6-21% of pigeon breeders found to develop extrinsic allergic alveolitis

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16
Q

What are the presenting symptoms of extrinsic allergic alveolitis?

A
Acute: (present 4-12 hours after exposure)
Dyspnoea
Fever
Dry cough
Chest tightness
Headache
Malaise
Myalgia
Chronic:
Increasing dyspnoea
Decreased exercise tolerance
Fatigue
Weight loss
17
Q

What are the signs on physical examination of extrinsic allergic alveolitis?

A

Acute:
Pyrexia
Rapid shallow breathing
Inspiratory crepitations

Chronic:
Fine inspiratory crepitations
Clubbing

18
Q

What are the appropriate investigations for extrinsic allergic alveolitis?

A

FBC - increased WBC, anaemia
ESR - elevated
Albumin - low in chronic disease

CXR - diffuse infiltrates, fibrosis, may be normal in acute episode
CT chest - ground-glass opacities
Bronchoalveolar lavage - fluid shows lymphocytosis and increased mast cells, positive antibody
Inhalation challenge - shows immunological response to causative antigen
Pulmonary function test - restrictive lung disease (low FEV1, low FVC, decreased TLC, increased FEV1/FVC)

Lung biopsy - granulomas, lymphocyte infiltration in alveolar wall - in patients with lack of exposure history or atypical presentation

19
Q

Define pneumoconiosis

A

A group of interstitial fibrosing lung diseases which are caused by chronic exposure and inhalation of metal, mineral and dust particles.

20
Q

Summarise the aetiology of pneumoconiosis

A

Caused by inhalation of particles of coal dust, silica and asbestos

Risk Factors:
Occupational exposure (coal mining, quarrying, iron & steel works, industry, plumbers)
High Cumulative dose of inhaled silica or coal
Cigarette Smoking
Tuberculosis (cofactors that contribute)

21
Q

Summarise the epidemiology of pneumoconiosis

A

Silicosis - sand blasting, silica miners
Coal worker’s pneumoconiosis - coal miner
Asbestosis - shipworker, roofing, insulation
Incidence is increasing in developed countries due to delayed disease following exposure

22
Q

What are the presenting symptoms of pneumoconiosis

A

Can be asymptomatic and picked up on routine CXR

Dyspnoea on exertion
Dry cough
Black sputum in coal workers pneumoconiosis
Pleuritic chest pain in Asbestosis

23
Q

What are the signs on physical examination of pneumoconiosis?

A

Crackles
Wheeze
Clubbing

Coal-worker’s pneumoconiosis and silicosis: Decreased breath sounds
Asbestosis: End-inspiratory crepitations & Clubbing

General: Cyanosis, Barrel Chest, Weight Loss

Signs of:
Pleural effusion or right heart failure (cor pulmonale)
Rheumatoid arthritis or scleroderma (uncommon complications of silica/coal exposure)
Renal Failure (may be presenting condition)

24
Q

What are the appropriate investigations of pneumoconiosis?

A

CXR:
Micronodular mottling
Silicosis - upper lobe eggshell calcification
Asbestosis - pleural and subdiaphragmatic plaques

Spirometry - restrictive lung disease - decreased FEV1, FVC, TLC, increased or normal FEV1/FVC

CT Scan: fibrotic changes can be visualised early, upper zone interstitial fibrosis (progressively involves the whole lung)
Bronchoscopy: allows visualisation and bronchoalveolar lavage

25
Define aspergillus lung disease
Lung disease associated with Aspergillus fungal infection (usually caused by aspergillus fumigatus)
26
Summarise the aetiology of aspergillus lung disease
Inhalation of the Aspergillus spores can produce 3 different clinical pictures: Aspergilloma: growth of an A. fumigates mycetoma ball in a pre-existing lung cavity i.e. post TB, old infarct or abscess Allergic Bronchopulmonary Aspergillosis: colonisation of airways by aspergillus leads to IgE &IgG mediated immune responses. The release of proteolytic enzymes, mycotoxins and antibodies leads to airway damage and central bronchiectasis. Usually occurs in asthmatics. Invasive Aspergillosis: invasion of aspergillus into lung tissue and fungal dissemination. Occurs in immunosuppressed patients i.e. neutropenia, aids, steroids ``` Risk factors: Allogenic stem cell transplantation Prolonged severe neutropenia (>10 days) Immunosuppressive therapy Aplastic anaemia ```
27
Summarise the epidemiology of aspergillus lung disease
Uncommon Clinical incidence is < 1 in 100 hospital admissions More common in males and immunocompromised
28
What are the presenting symptoms of aspergillus lung disease?
Aspergilloma: asymptomatic, haemoptysis (can be very significant), cough, weight loss, lethargy Allergic bronchopulmonary aspergillosis: difficulty in controlling asthma, recurrent episodes of pneumonia with wheeze, cough, fever and malaise Invasive aspergillosis: facial pain, dyspnoea, rapid deterioration, septic picture, headache, congestion or sinus tenderness, Intracranial space occupying lesion: seizure, altered mental status and cranial nerve palsy
29
What are the signs on physical examination of aspergillus lung disease?
Aspergilloma: tracheal deviation if large Allergic Bronchopulmonary Aspergillosis: dull affected lung, dull breath sounds, wheeze Invasive Aspergillosis: cyanosis
30
What are the appropriate investigations for aspergillus lung disease?
Aspergilloma: CXR: round opacity may be seen with crescent of air surrounding it (usually upper lobe) CT/MRI: if CXR does not clearly delineate opacification Sputum cultures may be -ve if no communication between colonised cavity & bronchial tree Allergic Bronchopulmonary Aspergillosis: Immediate skin test reactivity to Aspergillus antigens Eosinophilia, ↑ total serum IgE, ↑ specific serum IgE & IgG to A.fumigates CXR: transient patchy shadows collapse, distended mucus filled bronchi (bronchiectasis), Signs of complications: fibrosis in upper lobes and bronchiectasis CT: lung infiltrates, central bronchiectasis Lung Function Test: reversible airflow limitation, reduced lung volume/gas transfer Invasive Aspergillosis: Detection of Aspergillus in cultures OR histological examination Bronchoalveolar lavage fluid or sputum may be used diagnostically Chest CT: nodules surrounded by ground glass appearance ‘halo sign’ (haemorrhage into tissue surrounding area of fungal invasion