Lung abscess

Lung abscess : Suppuration of pus in a part of the lung caused by an infectious process.


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  • 1 Definition
  • 2 History
  • 3 Etiology
  • 4 Classification
    • 1 By the time of evolution of the symptoms:
    • 2 Due to associated conditions:
    • 3 From an anatomical-pathological point of view:
  • 5 Background:
    • 1 Infections of the lung parenchyma:
    • 2 Remote septic foci, such as:
    • 3 Septic foci by contiguity such as:
    • 4 Operations of the upper respiratory tract:
  • 6 Clinical Picture
    • 1 Symptoms
    • 2 Signs
  • 7 Laboratory tests
    • 1 Blood cultures:
    • 2 Sputum:
    • 3  Isolation even by invasive methods of the germs described for their specific treatment:
  • 8 Imaging studies
  • 9 Endoscopy
  • 10 Forecast
  • 11 References
  • 12 Sources


Localized suppuration and cavitation area in the lung , greater than two centimeters, with its own walls and air-fluid level in communication with a bronchus.


Lung abscess was a devastating and often fatal disease in the pre-antibiotic era, with evolutions of a third of the patients dying, another third recovering and the rest were left with great sequelae such as cachexia , chronic empyema, Bronchiectasis. In the early stages of the antibiotic era, sulfonamides did not obtain satisfactory results, beginning their effective treatment with the arrival of penicillins and tetracyclines. Although the role of surgery was considered essential in the past, today its role is practically nil due to resolution with antibiotic therapy.


-Tubercular, mycotic, secondary to bronchiectasis, infected cysts and even pulmonary infarcts that cavitate and abscess in their evolution.

– They are mainly caused by anaerobic microorganisms (Clostridim perfringens, septicum and peptostreptococcus), however mixed infections are frequent in which microorganisms from the oropharyngeal flora participate.

– The most frequently found aerobic germs are staphylococci , hemolytic and non-hemolytic streptococci and Escherichia coli.


By the time of evolution of the symptoms:

Acute or chronic if it had less or more than 8 weeks of evolution, respectively.

For associated conditions:

  1. Primary: previously healthy, aspiration-prone patients.
  2. Secondary: patients suffering from (Emphysema, Neoplasm of the lung, bronchiectasis and others) and / or general (Systemic diseases that compromise the immune system, such as AIDS ororgan transplantation).

From an anatomical-pathological point of view:

Simple. Gangrenous or putrid.


Pulmonary parenchymal infections:

  • Pneumonia, bronchopneumoniaand Pulmonary neoplasia.
  • Pneumonitis due to nocturnal physiological microaspirations from patients with dental gingiv diseases or oral sepsis with increased density of the bacterial population.
  • Bronchopneumonia due to aspiration of a foreign body or food remains in an unconscious patient: epilepsyalcoholism , cerebrovascular accidents, anesthesia.
  • In patients of advanced ages or with systemic or malignant diseases that depress the immune response to infection in which it is isolated, in addition to the aforementioned germs, pseudomonas, proteus and klebsielas. Bronchiectasis, etc.

Remote septic foci, such as:

Oropharyngeal sepsis, sinusitis, and piemia.

Septic foci by contiguity such as:

Hepatic and subphrenic abscesses.

Upper respiratory tract operations:

Use of positive pressure fans and mists made under insufficient sterilization conditions.

Clinical Picture


Patients are septic, sweaty, feverish, with a cough and sometimes putrid, foul-smelling expectoration that may be preceded by vomiting, presenting pleural chest pain and taking general condition. Sometimes they break, contaminating the pleural cavity and evolving towards the pyopneumothorax. Marked halitosis


Signs of pulmonary consolidation, with decreased vesicular murmur, crackling rales and dullness to percussion in the affected area. It is common to hear an amphoric or pleuritic murmur if there is pleural involvement.

Laboratory exams

Blood cultures:

They can be positive in patients with Staphylococcus Aureus infection and hematogenously spread gram-negative rods.


Gram staining and culture, for both aerobic and anaerobic germs.


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