II. Definitions

  1. Lung Abscess
    1. Localized lung cavity filled with pus
    2. Product of lung necrosis
    3. Cavity is often surrounded by infection

III. Causes: Organisms

  1. See Pneumonia Causes
  2. Oral Flora due to aspiration (most common, typically polymicrobial, anaerobic)
    1. Peptostreptococcus
    2. Prevotella
    3. Bacteroides
    4. Fusobacterium
  3. Pneumonia Complications
    1. Staphylococcal Pneumonia (Staphylococcus aureus)
    2. Gram Negative Pneumonia (e.g. KlebsiellaPneumoniae)
    3. Streptococcus Pyogenes
    4. HaemophilusInfluenzae Type B
  4. Other organisms
    1. Mycobacterium tuberculosis
    2. Nontuberculous Mycobacteria
    3. Fungal infection (e.g. Nocardia, Actinomyces)
    4. Atypical infections in travelers or Immigrants (e.g. Entamoeba histolytica, Echinococcus)

IV. Causes: Mechanisms

  1. Oropharyngeal Aspiration
    1. Dental Infections
    2. Sinus infections
    3. Altered Level of Consciousness (e.g. Intoxication, Alcoholism, Seizures)
    4. Gastroesophageal Reflux disease
    5. Frequent Vomiting
    6. Endotracheal Intubation
    7. Tracheostomy
  2. Hematologic Spread
    1. Infective Endocarditis
    2. IV Drug Abuse
    3. Central Line-Associated Bloodstream Infection
    4. Septic Thromboembolism
  3. Acute Lung Disorders
    1. Necrotizing Pneumonia
    2. Bronchial obstruction (e.g. foreign body, tumor)
    3. Lung Infarction (secondarily infected)
    4. Lung Contusion
  4. Chronic Lung Disorders
    1. Bronchiectasis
    2. Cystic Fibrosis
    3. Bullous Emphysema
    4. Congenital malformation
    5. Bronchoesophageal Fistula

V. Risk Factors

VI. Symptoms

  1. Fever
  2. Chills
  3. Night Sweats
  4. Productive cough of foul Sputum
  5. Dyspnea
  6. Fatigue
  7. Weight loss
  8. Pleuritic Chest Pain
  9. Hemoptysis

VII. Signs

  1. Localized dullness over involved lung
  2. Bronchial breath sounds or absent breath sounds
  3. Fingernail Clubbing

IX. Imaging

  1. Chest XRay
    1. Solitary cavitary lesion with air-fluid level
    2. Lesion surrounded by pneumonitis
  2. CT Chest
    1. Better defines infiltrates and cavitary lesions
    2. Explores differential diagnosis in refractory Lung Abscess
  3. Echocardiogram
    1. Consider in cases of suspected hematologic spread

X. Labs

  1. Sputum examination
    1. Microscopy
      1. Gram Stain
      2. Mycobacterial stains
      3. Fungal stains
    2. Sputum layers on standing
  2. Cultures
    1. Blood Cultures
    2. Sputum Cultures (often not helpful)
  3. Complete Blood Count
    1. Leukocytosis

XI. Diagnosis

  1. Bronchoscopy if proximal obstructing tumor is suspected

XII. Management: Antibiotics

  1. Initial Empiric Management (start with IV)
    1. Ampicillin-Sulbactam (Unasyn) 3 g IV every 6 hours
    2. Alternative options for Penicillin Allergy
      1. Clindamycin 600 mg IV every 8 hours or
      2. Moxifloxacin 400 mg IV every 24 hours or
      3. Levofloxacin 750 mg IV every 24 hours AND Metronidazole 500 mg IV every 8 hours
    3. Alternatives for suspected drug-resistant Gram Negative organisms
      1. Imipenem 1 g IV every 6 hours or
      2. Meropenem 1 g IV every 8 hours
  2. Symptom, Sign and Lab Improvement by 3 to 4 days (fever may persist 7-10 days)
    1. Adjust antibiotics as needed based on culture results
    2. Transition to oral antibiotics (plan 3 to 4 week outpatient course)
      1. Augmentin 875 mg orally twice daily
      2. Clindamycin 300 mg orally every 6 hours or
      3. Moxifloxacin 400 mg orally daily or
      4. Levofloxacin 750 mg orally daily AND Metronidazole 500 mg orally every 8 hours
  3. Failure to Improve or Worsening Despite IV Antibiotics at 3 to 4 days
    1. Adjust antibiotics as needed based on culture results
    2. Consider drug resistant Bacteria
    3. Consider atypical infection (e.g. Fungal Lung Infection, Mycobacteria)
    4. Consider differential diagnosis (see above)
    5. Obtain CT Chest
    6. Consider flexible bronchoscopy to obtain lesion sample and evaluate for airway obstructiuon or foreign body
    7. Consider abscess drainage (e.g. Intervention Radiology or transbronchial catheter)

XIII. Course

  1. Day 3 to 4
    1. Expect symptom, Vital Sign and lab (e.g. CBC) improvement on antibiotics
  2. Day 7 to 10
    1. Fever typically resolves by this time on antibiotics
  3. Day 21 to 50
    1. Abscess cavity typically closes by this time on antibiotics

XIV. Complications

  1. Respiratory Failure
  2. Pleural fibrosis
  3. Bronchopleural Fistula
  4. Pleurocutaneous Fistula

XV. Resources

  1. Bhanusivakumar (2022) Lung Abscess, StatPearls, Treasure Island
    1. https://www.ncbi.nlm.nih.gov/books/NBK555920/

XVI. References

  1. Klompas in Calderwood (2022) UpToDate, accessed 4/24/2022
  2. Kuhajda (2015) Ann Transl Med 3(13):183 +PMID: 26366400 [PubMed]

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Related Studies

Ontology: Lung Abscess (C0024110)

Definition (MSH) Solitary or multiple collections of PUS within the lung parenchyma as a result of infection by bacteria, protozoa, or other agents.
Definition (NCI) A bacterial, fungal or parasitic abscess that develops in the lung parenchyma. Causes include aspiration pneumonia, necrotizing pneumonia, necrotizing malignant tumors, and Wegener's granulomatosis.
Concepts Disease or Syndrome (T047)
MSH D008169
ICD9 513.0
ICD10 J85.2
SnomedCT 155618005, 196113000, 73452002
English Abscess, Pulmonary, Abscesses, Lung, Abscesses, Pulmonary, Lung Abscesses, Pulmonary Abscess, Pulmonary Abscesses, Abscess, Lung, PULMONARY ABSCESS, PULM ABSCESS, ABSCESS PULM, ABSCESSES PULM, PULM ABSCESSES, lung abscess (diagnosis), lung abscess, Lung abscess NOS, Abscess of lung NOS, Lung Abscess [Disease/Finding], abscess pulmonary, lung abscesses, Abscess;lung, abscess of lung, abscesses lung, of lung abscess, pulmonary abscess, pulmonary abscesses, abscess lung, abscess lungs, Abscess of lung NOS (disorder), Lung abscess (disorder), Lung abscess, Pulmonary abscess, Lungs--Abscess, Abscess of lung, Abscess of lung (disorder), abscess; lung, lung; abscess, Lung Abscess
Dutch longabces NAO, abces van long en mediastinum, abces; long, long; abces, longabces, Abces, long-, Abces, pulmonaal, Longabces
French Abcès au poumon, Abcès pulmonaire SAI, Abcès du poumon, Abcès pulmonaires, Abcès pulmonaire
German Abszess der Lunge, Lungenabszess NNB, Lungneabszess, Abszeß, Lungen-, Abszeß, pulmonaler, Lungenabszeß
Italian Ascesso del polmone, Ascesso polmonare NAS, Ascessi polmonari, Ascesso polmonare
Portuguese Abcesso pulmonar NE, Abcesso do pulmão, Abscesso Pulmonar
Spanish Absceso de pulmón, Absceso pulmonar NEOM, absceso pulmonar, SAI (trastorno), absceso pulmonar, SAI, absceso de pulmón (trastorno), absceso de pulmón, absceso pulmonar, Absceso pulmonar, Absceso Pulmonar
Japanese 肺膿瘍NOS, ハイノウヨウNOS, ハイノウヨウ, 肺膿瘍, 膿瘍-肺
Swedish Lungabscess
Finnish Keuhkopaise
Czech Absces plic, Plicní absces NOS, Plicní absces, absces plic, pulmonální absces, plicní absces, plíce - absces
Polish Ropień płuca
Hungarian tüdőtályog k.m.n., tüdőtályog, Tüdő abscessusa
Norwegian Pulmonal abscess, Pulmonale abscesser, Lungeabscess, Lungeabscesser