II. Epidemiology

  1. Represents <15% of all Community Acquired Pneumonia

III. Risk Factors

  1. Underlying Neurologic disease or Impairment (esp. depressed gas reflex)
    1. Cerebrovascular Accident
    2. Dementia
    3. Seizure
    4. Alcohol Intoxication
    5. Obtunded
  2. Esophageal dysfunction
  3. Anesthesia complication
  4. Microaspiration in Sleep Apnea

IV. Etiology: Anaerobic Bacteria or Mixed oropharyngeal flora

  1. Bacteroides
  2. Peptostreptococcus
  3. Microaerophilic Streptococcus
  4. Fusobacterium
  5. Nocardia

V. Pathophysiology

  1. Necrotizing infection may lead to cavitation
  2. Affects dependent lung lobes

VI. Symptoms

  1. Low grade fever
  2. Weight loss
  3. Productive cough with foul smelling Sputum

VIII. Labs

  1. Sputum Gram Stain unreliable
    1. Typically demonstrates mixed oral flora and many PMNs
  2. Sputum Culture unreliable

IX. Imaging

  1. Chest XRay (often negative initially)
    1. RadAspirationPneumoniaPaMedPix6057.jpgFrom MedPix with permission.
    2. RadAspirationPneumoniaLateralMedPix6058.jpgFrom MedPix with permission.
    3. Typically involves dependent lung tissue

X. Management: General

  1. Initial aspiration event results in chemical pneumonitis
    1. When this is witnessed (e.g. under anesthesia, Endotracheal Intubation), do not immediately start antibiotics
      1. Await the development of Pneumonia (fever, symptoms) to institute antibiotics
      2. Empiric antibiotic prophylaxis after witnessed aspiration results in worse outcomes (e.g. Antibiotic Resistance)
  2. Antibiotics
    1. Antibiotic course for up to 3-4 weeks
    2. Extend antibiotic course up to 2-3 months for Lung Abscess

XI. Management: Oral Antibiotics

  1. First-Line
    1. Clindamycin 300-450 mg orally three times daily
    2. Moxifloxacin 400 mg once daily
  2. Alternative
    1. Amoxicillin-Clavulanate 875 orally twice daily

XII. Management: Parenteral Antibiotics

  1. First Line
    1. Ceftriaxone 1 g IV every 24 hours AND Metronidazole 500 mg IV every 6 hours (or 1 g IV every 12 hours) OR
    2. Ampicillin-Sulbactam 3 g IV every 6 hours
  2. Alternative
    1. Piperacillin-Tazobactam (Zosyn) 3.375 g IV every 6 hours OR
    2. Ertapenem 1 g IV every 24 hours

XIII. Prevention

  1. Evaluate with Swallowing Exam
  2. Dysphagia Diet for moderate to severe Dysphagia

XIV. Prognosis: Predictors of worse outcomes

  1. Lower pH (<2.5)
  2. Larger volume aspiration (>25 ml)
  3. Particulate matter aspirated (e.g. food)
  4. Bacterial contamination (esp. Anaerobic Bacteria)

XV. References

  1. Swadron (2019) Pulmonology 2, CCME Emergency Medicine Board Review, accessed 6/16/2019
  2. Gilbert (2016) Sanford Antimicrobial, accessed IOS app 12/6/2016
  3. Lomotan (1997) Postgrad Med 102(2):225-31 [PubMed]
  4. Sasaki (1997) Intern Med 36(12):851-5 [PubMed]

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Ontology: Aspiration Pneumonia (C0032290)

Definition (MSH) A type of lung inflammation resulting from the aspiration of food, liquid, or gastric contents into the upper RESPIRATORY TRACT.
Concepts Pathologic Function (T046)
MSH D011015
ICD10 J69.0
SnomedCT 422588002, 47839005
LNC LA7415-8
English Aspiration Pneumonias, Pneumonia, Aspiration, Pneumonias, Aspiration, ASPIRATION PNEUMONIA, Aspiration pneumonitis, Aspiration pneumonia, Inhalation pneumonia, Aspiration pneumonia (disorder), aspiration pneumonia (diagnosis), aspiration pneumonia, Pneumonia aspiration, Inhalational pneumonia, pneumonia, inhalation, Aspiration pneumonia NOS, Pneumonia, Aspiration [Disease/Finding], Pneumonia;aspiration, inhalation pneumonia, aspiration pneumonitis, pneumonia aspiration, pneumonia; aspiration, Aspiration pneumonia, NOS, Aspiration Pneumonia
Dutch aspiratie pneumonie, pneumonie; aspiratie, aspiratiepneumonie, Aspiratiepneumonie, Pneumonie, aspiratie-
French Pneumonie par aspiration, Pneumopathie de déglutition, Pneumonie de déglutition, Bronchopneumopathie de déglutition, Pneumopathie d'inhalation, Pneumopathie par régurgitation
German Inhalationspneumonie, Aspirationspneumonie, Pneumonie, Aspirations-
Italian Polmonite da inalazione, Polmonite da aspirazione
Portuguese Pneumonia por inalação, Pneumonia por Aspiração, Pneumonia por aspiração, Pneumonia Aspirativa
Spanish Neumonía por inhalación, Neumonía inhalatoria, neumonía por aspiración, neumonía por inhalación, neumonía por aspiración (trastorno), neumonía aspirativa, neumonía aspirativa (trastorno), Neumonía por aspiración, Neumonía por Aspiración
Japanese 吸入性肺炎, キュウニュウセイハイエン, 酸吸引症候群, 吸引性肺炎, 誤嚥性肺炎, 吸引肺炎, 肺炎-誤嚥性, 肺炎-吸引性, 誤飲性肺炎, ゴエンセイハイエン, 嚥下性肺炎, 肺炎-嚥下性
Swedish Aspirationspneumoni
Finnish Aspiraatiokeuhkokuume
Czech Pneumonie aspirační, Inhalační pneumonie, Aspirační pneumonie, aspirační pneumonie, pneumonie aspirační
Polish Zespół Mendelsona, Zapalenie płuc zachłystowe, Zapalenie płuc aspiracyjne
Hungarian Aspiratiót követő pneumonia, Inhalatios pneumonia, Aspiratiós pneumonia
Norwegian Aspirasjonspneumoni