15. Pulmonary abscess. Pulmonary gangrene. Bronchiectasis. Flashcards
Pulmonary Abscess - Definition
Localized area of necrosis + suppuration (liquefactive necrosis)
Pulmonary Abscess - Types
- Primary: in healthy lung usually aspiration of infected material
- Secondary: complication of other lung diseases
- Acute = <6wks Chronic = >6wks
Pulmonary Abscess - Etiology
Strep/Staph G-ve bact – introduced via aspiration (most common)
bronchial obstruction
septic embolism
trauma
Pulmonary Abscess - Clinical Presentation
6
fever
malaise
cough
chest pain
purulent-foul smelling sputum (same as bronchiectasis)
haemoptysis (50%), finger + toe clubbing (20%)
Pulmonary Abscess - Pathogenesis
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
Pulmonary Abscess - Treatment
antibiotics – penicillin (continue until healed)
metronidazole – anaerobic = clindamycin; S.aureus, pseudomonas, Enterobacter = vancomycin
- Postural drainage
- Surgical excision = if repeated aspiration
Pulmonary Abscess - Diagnostic Investigations
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
Pulmonary gangrene AKA necrotising pneumonia
Definition
pneumonia charac by development of necrosis within infec lung tissue
Pulmonary gangrene AKA necrotising pneumonia
Steps
- 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
Pulmonary gangrene - Etiology
S.aureus
klebsiella pneumonia
Enterobacter etc.
CAP complication
Pulmonary gangrene -
Clinical Presentation
severe pneumonia (weight loss, fever, night sweats)
pleural effusion
emphysema
abscess
Pulmonary gangrene - Diagnostic Investigations
CXR – dense lobar consolidation + p.effusion, multiple air/fluid filled cavities.
CT – with contrast areas of low attenuation with decreased parenchymal enhancement (representing liquefaction)
Pulmonary gangrene - Treatment
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
Bronchiectasis: - Regular Definition
chronic inflam of bronchi + bronchioles leading to permanent dilatation + thinning of these airways
Bronchiectasis: - Anatomical Definition
irreversible abnormal dilation of one or more bronchi with chronic airway inflam
