Lung abscess , clinical features, etiology, pathogenesis, pathology
LUNG ABSCESS
Lung abscess is a pus filled cavity in the lungs due to infection and destruction of lung tissue.
CLINICAL FEATURES OF LUNG ABSCESS
1-Pleuritis
2-Empyema
3-Hemorrhage
4-Sepsis
5-Meningitis
6-Secondary amyloidosis
ETIOLOGY
1-Aspiration of infective material in to lungs may due to various types of disease condition like coma and epilepsy
2-.if patient had suffering previously pneumonia or any bacterial infection there is also chanse of destruction of lung tissue.and formation of lung abscess.
3-If patient suffering Recurrent tubercular infection there is also lung tissue destruction and formation of lung abscess occurs.
4- Septic embolism – Infected clot travel through blood stream by blood and bacteria spread to lung tissue so lung abscess occurs.
5-As a complication of malignancies where the tumor obstructs the air way leading growth of bacteria and infection,this infection spread to lung tissue and lungs abscess occurs.
Name of the Pathogenic organisms involved are
- Anaerobic bacteria (most common)
- Bacteroides
- Peptostreptococcus
- Fusobacterium
Aerobic bacteria - Staphylococcus aureus
- Streptococcus pneumoniae
- Klebsiella pneumoniae
- Pseudomonas aeruginosa
- Escherichia coli (E. coli)
Others - Fungi
- Mycobacterium tuberculosis may rarely cause abscess formation.
RISK FACTORS
1-Alcoholism
2-Seizure disorder
3-Neuromuscular disorder
4-Drug Overdose
5-General anaesthesia
6-Stroke
7-Immunocompromised patient
8- ICU patient
PATHOGENESIS
Due to Etiology may be tumor, pneumonia or aspiration
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Bacteria enter and grow in lung tissue.
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Develop infection and inflammation
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Pus formation occur
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A cavity filled with pus develops
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Forms lung abscess
COMPLICATION OF LUNG ABSCESS
1-Chronic abscess
2-Empyema
3-Bleeding
4- Bronchopleural fistula
Pathological changes
Gross appearance
Abscess vary in size ranging from a few mm to 6cm may be single and multiple.
HISTOLOGICAL CHANGES
Destruction of the alveolar space
DIAGNOSIS
Physical examination
Dullness to percussion
Decreased breath sound on Auscultation over the segment of lung involved
Crackles
Radiological
CT SCAN
MRI
chest xray
CULTURE
Sputum culture
Pleural fluid or blood culture
Bronchoscopy
