II. Definitions

  1. Aspiration Pneumonia
    1. Pneumonia due to food, liquid or gastric contents aspirated into the upper respiratory tract
  2. Aspiration Pneumonitis (chemical pneumonitis)
    1. Chemical aspiration of acidic gastric contents
      1. Degree of injury increases with gastric acidity (significant if gastric pH<2.5)
    2. With normal gastric acidity, Stomach contents are typically sterile
      1. However, not sterile in Antacid use, enteral feeding, Gastroparesis, poor Dentition and Small Bowel Obstruction

III. Epidemiology

  1. Represents <15% of all Community Acquired Pneumonia

IV. 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
  5. Poor Dentition or severe gum disease

V. Etiology: Anaerobic Bacteria or Mixed oropharyngeal flora

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

VI. Pathophysiology

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

VII. Symptoms

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

VIII. Signs

IX. Labs

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

X. 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

XI. Management: General

  1. Initial aspiration event results in chemical pneumonitis (not Pneumonia)
    1. When this is witnessed (e.g. under Anesthesia, Endotracheal Intubation), do not immediately start antibiotics
    2. Await the development of Pneumonia (fever, symptoms) to institute antibiotics
      1. Empiric antibiotic prophylaxis after witnessed aspiration results in worse outcomes (e.g. Antibiotic Resistance)
      2. Consider early antibiotics in Antacid use, enteral feeding, Gastroparesis and Small Bowel Obstruction
  2. Antibiotics
    1. Typical Pneumonia organisms are more common than Anaerobes even in patients at aspiration risk
      1. Consider starting with typical Community Acquired Pneumonia Management
      2. However, start with anaerobic coverage if poor Dentition or gum disease
      3. Add anaerobic coverage if failure to respond to initial antibiotics
    2. Antibiotic course for up to 3-4 weeks
    3. Extend antibiotic course up to 2-3 months for Lung Abscess

XII. 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

XIII. 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

XIV. Prevention

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

XV. 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)

XVI. References

  1. (2019) Presc Lett 26(9):50
  2. Swadron (2019) Pulmonology 2, CCME Emergency Medicine Board Review, accessed 6/16/2019
  3. Gilbert (2016) Sanford Antimicrobial, accessed IOS app 12/6/2016
  4. Lomotan (1997) Postgrad Med 102(2):225-31 [PubMed]
  5. Sasaki (1997) Intern Med 36(12):851-5 [PubMed]

Images: Related links to external sites (from Bing)

Related Studies

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

Ontology: Pneumonitis due to inhalation of food or vomitus (C0260334)

Concepts Disease or Syndrome (T047)
ICD9 507.0
ICD10 J69.0
SnomedCT 196036007, 196032009
English Pneumonitis due to inhalation of food or vomitus NOS, Pneumonitis-food/vomit NOS, Pneumonitis-food/vomit inhal., Pneumonitis due to food and vomit, Pneumonitis due to inhalation of food or vomit, Food/vomit pneumonitis, Pneumonitis due to inhalation of food or vomitus NOS (disorder), Pneumonitis due to inhalation of food or vomitus, Pneumonitis due to inhalation of food or vomitus (disorder)
Dutch pneumonitis door aspiratie van voedsel of braaksel, Pneumonitis door voedsel en braaksel
French Pneumonite due à l'inhalation de nourriture ou de vomi, Pneumopathie due à l'inhalation d'aliments ou vomissures
German Pneumonitis durch Inhalation von Essen oder Erbrochenem, Pneumonie durch Nahrung oder Erbrochenes
Italian Polmonite da inalazione di cibo o vomito
Portuguese Pneumonite por aspiração de alimentos ou vómitos
Spanish Neumonitis por aspiración de comida o vómitos, neumonitis debida a inhalación de comida o vómitos, SAI, neumonitis debida a inhalación de comida o vómitos, SAI (trastorno), neumonitis por inhalación de alimento o vómito (trastorno), neumonitis por inhalación de alimento o vómito
Japanese 食物または吐物の吸引による肺臓炎, ショクモツマタハトブツノキュウインニヨルハイゾウエン
Czech Pneumonitida z aspirace potravy nebo zvratků
Korean 음식 또는 구토물에 의한 폐렴
Hungarian Élelem vagy hányás-inhalatio okozta pneumonitis, Étel- vagy hányás-inhalatio okozta pneumonitis