Obstructive Lung Disease

Question 1

Asthma

Define

Answer 1

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.

Question 2

Types of Asthma

Answer 2

Extrinsic: starts in childhood, hay fever & eczema,
Atopic hypersensitivity, IgE mediated, type 1 allergic reaction

Allergens: pollen, dust mites,

Intrinsic: may develop with age

Question 3

Type 3 allergic reaction

Extrinsic non-atopic asthma

Answer 3

Mediated by percipitins
Dependant on fixation of complement
Accompanied by fever & leucocytosis

Fix: steroid therapy

Question 4

Asthma Morphology

Answer 4

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

Question 5

Chronic Bronchitis

Define

Answer 5

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.

Question 6

Chronic Bronchitis

Aetiology

Answer 6

Cigarette smoking, air pollution, fumes at work, fog, smog, damp cold climate

Question 7

Chronic Bronchitis

Morphology

Answer 7

Micro: enlarge bronchial glands, increased mucous, sputum viscosity, sulphomucin

Squamous metastasis, loss of cilia, goblet cell metastasis

Question 8

Chronic Bronchitis

Complications

Answer 8

RV failure
Infection
Bronchiectasis

Question 9

Emphysema

Define

Answer 9

An abnormal, permanent increase in size of the airspaces distal to the terminal bronchiole, accompanied by destructive changes.

Question 10

Emphysema

Types

Answer 10

Centrilobular 
Focal dust
Panacinar 
Paracicatricial 
Paraseptal
Bullous disease of the lung

Question 11

Centrilobular Emphysema

Answer 11

From destroyed bronchioles

Inflam of bronchi, bronchiole, septa

Stenosed airway

Question 12

Focal dust Emphysema

Answer 12

Due to Carbon dust inhalation

Fusifirm dialation

No inflam/ stenosis

Question 13

Panacinar Emphysema

Answer 13

Affects acinus uniformly

Permanent enlargement: alveoli/ducts, bronchioles

No inflam

Question 14

Paracicatricial Emphysema

Answer 14

Scars:lung parenchyma + Emphysemous spaces

Increase elastic pull of alveoli

Bronchial narrowing: fibrosis & inflam

Question 15

Paraseptal Emphysema

Answer 15

Localised adjacent to interlobular septa & pleura

Question 16

Bullous disease of the lung

Answer 16

Large air filled cysts in apices

Question 17

Centrilobular Emphysema

Aetiology & pathogenesis

Answer 17

Aet: cigarette smoke/ cadmium fumes

Causes: bronchioles & adjacent alveoli damage

Affects: upper lobes

Cadmium-> macrophage lysosome damage-> enzyme release

Question 18

Panacinar Emphysema

Aet & pathogenesis

Answer 18

Aet: genetic alpha 1- antitrypins deficiency

Results: liver(infants) & lung(adult) disease

Nuetrophils-> Proteolytic enzymes-> gradually destroy lungs

Question 19

Protease-antiprotease theory

Answer 19

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

Question 20

Emphysema Complications

Answer 20

Pneumothorax
Air embolism
RV failure
Infection: bronchitis / bronchoPneumonia

Question 21

Centrilobular Emphysema

Clinical effects

Answer 21

Associated: chronic bronchitis

Increased dead space / spasm of small arteries

Anastomoses(Pulm.artery/bronchial artery with systemic pressure) -> pulm. HTP

Question 22

Panacinar Emphysema

Clinical effects

Answer 22

Pulm HTP not as noticable due to compensation( increase RR)