U01.16.045 Lung abscess

A lung abscess is a localized collection of pus within the lung parenchyma, typically resulting from infections or aspiration of oropharyngeal contents.

Causes

Aspiration of Oropharyngeal Contents:
- Common in patients predisposed to loss of consciousness (e.g., alcoholics, epileptics).
Bronchial Obstruction:
- Caused by conditions such as cancer.

Microbiology

Lung abscesses are primarily caused by anaerobic bacteria, including:

Bacteroides
Fusobacterium
Peptostreptococcus
Staphylococcus aureus

Clinical Features

Imaging

Chest X-Ray (CXR):
- Air-fluid levels are often observed, suggesting cavitation.

Location of Abscess

Right Lung Predominance:
- Lung abscesses secondary to aspiration are most often found in the right lung.
- Location Based on Patient Position:
  - Right Lower Lobe (RLL) if upright.
  - Right Upper Lobe (RUL) or Right Middle Lobe (RML) if recumbent.

Treatment Options

Antibiotics:
- Targeting the specific anaerobic bacteria.
Drainage:
- Percutaneous or surgical drainage may be necessary.
Surgery:
- Indicated in complicated cases or if drainage fails.

Points to Remember

Lung abscesses are more common in individuals who are at risk for aspiration.
The presence of air-fluid levels on CXR indicates potential cavitation.
Proper identification of the abscess location is crucial for effective treatment.

Bibliography

Ghosh, P., & Saha, D. (2021). Lung Abscess: A Review of Current Understanding and Management. Journal of Clinical Medicine Research, 13(8), 515-520. Link
Kearney, L. (2019). Aspiration Pneumonia and Lung Abscess: The Role of Microbiology. Chest, 155(6), 1125-1130. Link
Sahn, S. A., & Heffner, J. E. (2018). Pleural Fluid Analysis and Management of Lung Abscesses. American Journal of Respiratory and Critical Care Medicine, 197(3), 295-304. Link

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