[Pathophysiology and Therapeutic Approach of Pulmonary Aspiration]

Pulmonary aspiration is one of the serious adverse events in general anesthesia. Aspiration induced lung injury varies according to the nature of the contents of aspirates (acid or small particles in gastrointestinal tract, bile acid), amount of aspirates, and host-defense status. Early inflammatory responses to acid and small particles from gastrointestinal contents are categorized as aspiration pneumonitis causing rapid respiratory deterioration with early restoration of lung injury within a couple of days. Late phase lung injury is usually "aspiration pneumonia" caused by bacteria colonized in the aspirates. Treatment mainstream is to support respiratory function until the lung resolves from injury. Extracorporeal membrane oxygenation is another promising therapeutic option for cases with severe lung damage to keep the "lung rest" during fulminant lung injury, avoiding further lung damage by injurious ventilation. Empirical administration of antibiotics covering wide spectrum followed by meticulous bacteriological studies to either de-escalate or discontinue antibiotics is crucial.