15. Pulmonary abscess. Pulmonary gangrene. Bronchiectasis.

Question 1

Pulmonary Abscess - Definition

Answer 1

Localized area of necrosis + suppuration (liquefactive necrosis)

Question 2

Pulmonary Abscess - Types

Answer 2

• Primary: in healthy lung usually aspiration of infected material
• Secondary: complication of other lung diseases
• Acute = <6wks Chronic = >6wks

Question 3

Pulmonary Abscess - Etiology

Answer 3

Strep/Staph G-ve bact – introduced via aspiration (most common)

bronchial obstruction

septic embolism

trauma

Question 4

Pulmonary Abscess - Clinical Presentation

6

Answer 4

fever

malaise

cough

chest pain

purulent-foul smelling sputum (same as bronchiectasis)

haemoptysis (50%), finger + toe clubbing (20%)

Question 5

Pulmonary Abscess - Pathogenesis

Answer 5

Area of pneumonia becomes small zones of liquefactive necrosis

Small zones – join to form large cavities –

Large cavities progress to abscess cavity –

abscess cavity erodes bronchus –

in abscess cavity there is formation of purulent sputum with air fluid

Question 6

Pulmonary Abscess - Treatment

Answer 6

antibiotics – penicillin (continue until healed)

metronidazole – anaerobic = clindamycin; S.aureus, pseudomonas, Enterobacter = vancomycin

• Postural drainage
• Surgical excision = if repeated aspiration

Question 7

Pulmonary Abscess - Diagnostic Investigations

Answer 7

Blood FBC- anaemia, neutrophilia; ESR, CRP, blood culture

Sputum microscopy

culture

cytology

CXR: walled cavity, often with a fluid level

CT: to exclude obstruction

Bronchoscopy: for obtaining diagnostic specimen

Question 8

Pulmonary gangrene AKA necrotising pneumonia

Definition

Answer 8

pneumonia charac by development of necrosis within infec lung tissue

Question 9

Pulmonary gangrene AKA necrotising pneumonia

Steps

Answer 9

• Severe complication of Community Acquired Pneumonia – charac by liquefaction + cavitation of lung tissue inflame, consolidation, peripheral necrosis + small multiple cavities
• Compromise of bronchial + pulmonary vascular supply – impeding delivery of antibiotics
• Pulmonary gangrene = final stage if necrotising pneumonia progress uncontrollably

Question 10

Pulmonary gangrene - Etiology

Answer 10

S.aureus

klebsiella pneumonia

Enterobacter etc.

CAP complication

Question 11

Pulmonary gangrene -
Clinical Presentation

Answer 11

severe pneumonia (weight loss, fever, night sweats)

pleural effusion

emphysema

abscess

Question 12

Pulmonary gangrene - Diagnostic Investigations

Answer 12

CXR – dense lobar consolidation + p.effusion, multiple air/fluid filled cavities.

CT – with contrast areas of low attenuation with decreased parenchymal enhancement (representing liquefaction)

Question 13

Pulmonary gangrene - Treatment

Answer 13

Antibiotics – dependent on underlying agent, Pulmonary resection of all gangrenous tissue is mandatory

• Pulmonary emphysema commonly accompanies gangrene, in its presence, dissection of hilar structures for resection can lead to mediastinitis or bronchopleural fistula + should be avoided

Question 14

Bronchiectasis: - Regular Definition

Answer 14

chronic inflam of bronchi + bronchioles leading to permanent dilatation + thinning of these airways

Question 15

Bronchiectasis: - Anatomical Definition

Answer 15

irreversible abnormal dilation of one or more bronchi with chronic airway inflam

Question 16

Bronchiectasis: - Clinical Definition

Answer 16

chronic sputum production, recurrent chest infections + airway obstruction

Question 17

Bronchiectasis: - Etiology

Answer 17

infection

immune deficiency

idiopathic (50%)

slight female predominance

Question 18

Bronchiectasis: - Pathophysiology:

Answer 18

Principally affects medium sized bronchi.

This causes dilated bronchi filled with purulent secretions.

This results in mucosal edema, ulceration + neovascularisation

Not only bronchi damaged, vessels also (tortous bronchial arteries)

Question 19

Bronchiectasis: - Clinical Presentation

5

Answer 19

chronic sputum production which foul smelling

haemoptysis

decreased breathing

pleuritic pain

cough

Question 20

Bronchiectasis: - Diagnostic investigations

Answer 20

• Physical exam: auscultation – crackles, prolonged expiration

digital clubbing

bronchial breath sounds

• Radiological: dilated bronchi – tramline + ring shadows

Question 21

Bronchiectasis: - Radiological classification:

Answer 21

Normal, cylindrical, varicose, cystic

Question 22

Bronchiectasis: - Treatment

5

Answer 22

Antibiotic ciprofloxacin - for pseudomonas

• Airway clearance techniques
• Mucolytics = carbocysteine
• Bronchodilators
• Corticosteroids

Question 23

Bronchiectasis: - SURGICAL

Answer 23

Surgery:
indicated in
localised
diseases or to
control severe
haemoptysis.

In
severe cases –
lung
transplantation,
surgical
resection,
thoracotomy