Obstructive Lung Disease Flashcards
Asthma
Define
Disease characterised by increased irritability of the tracheobronchial tree, resulting in the paroxysmal narrowing of the bronchial airways which may reverse spontaneously or under treatment.
Types of Asthma
Extrinsic: starts in childhood, hay fever & eczema,
Atopic hypersensitivity, IgE mediated, type 1 allergic reaction
Allergens: pollen, dust mites,
Intrinsic: may develop with age
Type 3 allergic reaction
Extrinsic non-atopic asthma
Mediated by percipitins
Dependant on fixation of complement
Accompanied by fever & leucocytosis
Fix: steroid therapy
Asthma Morphology
Macro: Desquamated resp. Epithelial, eosinophil, mucus
Micro: plugs in bronchial lumen, metaplastic change, thick BM, dilated congested capillaries, oedema, eosinophils, hypertrophy of Sm.muscle & mucous glands
Chronic Bronchitis
Define
Clinical entity characterised by a cough productive of sputum, in the absence of cardiac or pulmonary disease, produced for 3 months of the year for 2 consecutive years.
A airflow limitation involving the conducting airways, due to thickening if the wall and intermittent lumenal plugging.
Chronic Bronchitis
Aetiology
Cigarette smoking, air pollution, fumes at work, fog, smog, damp cold climate
Chronic Bronchitis
Morphology
Micro: enlarge bronchial glands, increased mucous, sputum viscosity, sulphomucin
Squamous metastasis, loss of cilia, goblet cell metastasis
Chronic Bronchitis
Complications
RV failure
Infection
Bronchiectasis
Emphysema
Define
An abnormal, permanent increase in size of the airspaces distal to the terminal bronchiole, accompanied by destructive changes.
Emphysema
Types
Centrilobular Focal dust Panacinar Paracicatricial Paraseptal Bullous disease of the lung
Centrilobular Emphysema
From destroyed bronchioles
Inflam of bronchi, bronchiole, septa
Stenosed airway
Focal dust Emphysema
Due to Carbon dust inhalation
Fusifirm dialation
No inflam/ stenosis
Panacinar Emphysema
Affects acinus uniformly
Permanent enlargement: alveoli/ducts, bronchioles
No inflam
Paracicatricial Emphysema
Scars:lung parenchyma + Emphysemous spaces
Increase elastic pull of alveoli
Bronchial narrowing: fibrosis & inflam
Paraseptal Emphysema
Localised adjacent to interlobular septa & pleura
Bullous disease of the lung
Large air filled cysts in apices
Centrilobular Emphysema
Aetiology & pathogenesis
Aet: cigarette smoke/ cadmium fumes
Causes: bronchioles & adjacent alveoli damage
Affects: upper lobes
Cadmium-> macrophage lysosome damage-> enzyme release
Panacinar Emphysema
Aet & pathogenesis
Aet: genetic alpha 1- antitrypins deficiency
Results: liver(infants) & lung(adult) disease
Nuetrophils-> Proteolytic enzymes-> gradually destroy lungs
Protease-antiprotease theory
Serous acini(bronchial glands) & Clara cells(bronchioles)-> antiproteases
Irritants-> phagocytic cells-> proteases
-> increase in A. Macrophages-> proteolytic enzymes
Inflam-> neutrophils-> proteolytic enzymes
Therefore protease»> antiproteases
Result: Emphysema + loss of elastic recoil
Emphysema Complications
Pneumothorax
Air embolism
RV failure
Infection: bronchitis / bronchoPneumonia
Centrilobular Emphysema
Clinical effects
Associated: chronic bronchitis
Increased dead space / spasm of small arteries
Anastomoses(Pulm.artery/bronchial artery with systemic pressure) -> pulm. HTP
Panacinar Emphysema
Clinical effects
Pulm HTP not as noticable due to compensation( increase RR)
