Lung abscess 2013

Contents: Causes Signs and symptoms DiagnosisManagementComplicationsPrognosis

Lung abscess is necrosis of the pulmonary tissue and formation of cavities (more than 2 cm) containing necrotic debris or fluid caused by microbial infection. Alcoholism is the most common condition predisposing to lung abscesses.

Lung abscess Primary (60%) Secondary (40%)

Secondary when it complicates another process another processprimary when it results from existing lung from existing lung parenchymal process parenchymal process

Causes Organisms Other factors Pathological disease

Conditions contributing to lung abscess Aspiration of oropharyngeal or gastric secretion Septic emboli Necrotizing pneumonia Vasculitis Necrotizing tumors Necrotizing tumors :

Organisms Anaerobic bacteria: Peptostreptococcus, Fusobacterium species. Microaerophilic streptococcus : Streptococcus milleri. Aerobic bacteria: Staphylococcus, Streptococcus. Fungi: Candida, Aspergillus.,

Anaerobic bacteria: Peptostreptococcus. Fusobacterium species.

Microaerophilic streptococcus : Streptococcus milleri.

Aerobic bacteria: Staphylococcus. Streptococcus. Streptococcus.

Fungi: Candida. Aspergillus. Aspergillus.

Signs and symptoms Onset of symptoms is often gradual, but in necrotizing staphylococcal or gram-negative bacillary pneumonias patients can be acutely ill. Cough, fever with shivering and night sweats are often present. Cough can be productive with foul smelling purulent sputum (70%) or less frequently with blood. Affected individuals may also complain of chest pain, shortness of breath, lethargy and other features of chronic illness.

Diagnosis Chest X-ray and other imaging studies Laboratory studies

Complications Rare nowadays but include spread of infection to other lung segments, bronchiectasis, empyema, and bacteraemia with metastatic infection such as brain abscess.