Pulmonology

Aspiration Pneumonia

흡인성폐렴

Lung infection from aspiration of oropharyngeal/gastric contents

Written and edited by Dr. Kwang Lee, D.C., L.Ac. · Updated 2026-10-04

How common: Common in elderly/neurologic patients
Typical age: Elderly predominant

What is it?

Oropharyngeal or gastric contents enter lungs causing anaerobic infection and chemical injury.

Commonly affected: Dependent lobes (RLL upright, RUL supine)

How it develops

Dysphagia/altered consciousnessStroke, dementia, intoxication
AspirationOral/gastric contents enter airway
Chemical pneumonitisGastric acid injures alveoli (Mendelson)
Bacterial infectionAnaerobes (oral flora) predominate

Symptoms

Fever/cough24–48 hrs after aspiration
Dyspnea/hypoxiaMay progress to ARDS
Foul-smelling sputumSuggests anaerobic infection

How it is examined

Aspiration historyAssess dysphagia/altered consciousness
Swallow studyModified barium swallow

Imaging

Infiltrate in dependent zones (RLL or RUL).

Dependent infiltrate
Lung abscess

Chest CT for abscess/necrotizing pneumonia.

Lung abscess
Air-fluid level

Non-surgical care

Empiric antibioticsAmpicillin-sulbactam or clindamycin (anaerobic cover)
Swallow rehab/preventionDiet modification, posture, oral hygiene
Supportive careOxygen, fluids, suctioning

Conservative options are generally tried first. Medications listed here can have side effects — discuss them with your prescriber.

When surgery is considered

Large abscess or complications

Procedures that may be discussed

Percutaneous or VATS drainage

Outlook

Improves with early antibiotics; worse with abscess formation.