Lung abscess

Lung abscess is a circumscribed collection of pus in the lung that leads to cavity formation.

Aspiration of gastric contents is the most common causative factor. Mixed microbial flora, including anaerobic bacteria and microaerophilic streptococci, are involved in abscess formation related to the aspiration of gastric contents.

Fever associated with a productive cough and putrid expectoration is a common clinical manifestation.

Diagnosis is based on radiological findings of cavitation with an air-fluid level. Documenting anaerobic infection is usually difficult.

Treatment options include antimicrobial agents against aerobic and anaerobic bacteria, given alone or in combination.

Reserve image-guided percutaneous drainage or surgical resection for patients not responding to antimicrobial treatment.

A lung abscess is a localised collection of pus within the lung that leads to cavitation that usually has a thick wall.[1]Tuddenham WJ. Glossary of terms for thoracic radiology: recommendations of the Nomenclature Committee of the Fleischner Society. AJR Am J Roentgenol. 1984 Sep;143(3):509-17. http://www.ajronline.org/doi/pdf/10.2214/ajr.143.3.509 http://www.ncbi.nlm.nih.gov/pubmed/6380245?tool=bestpractice.com [2]Bartlett JG. Anaerobic bacterial infections of the lung. Chest. 1987 Jun;91(6):901-9. http://journal.chestnet.org/article/S0012-3692(15)43176-9/fulltext http://www.ncbi.nlm.nih.gov/pubmed/3556058?tool=bestpractice.com Abscesses occur most commonly when microbial infection causes necrosis of the lung parenchyma, forming 1 or more cavities. Communication of such cavities with the bronchial tree results in a cough productive of purulent sputum and the presence of air-fluid levels on chest x-ray.[3]Mansharamani NG, Koziel H. Chronic lung sepsis: lung abscess, bronchiectasis, and empyema. Curr Opin Pulm Med. 2003 May;9(3):181-5. http://www.ncbi.nlm.nih.gov/pubmed/12682562?tool=bestpractice.com