Aspiration Pneumonia in Older Adults
Aspiration pneumonia refers to an infection of the lung parenchyma in an individual that has inhaled a bolus of endogenous flora that overwhelms the natural defenses of the respiratory system. While there are not universally agreed upon criteria, the diagnosis can be made in patients with the appropriate risk factors and clinical scenario, in addition to a radiographic or an ultrasonographic image of pneumonia in the typical dependent lung segment. Treatment options for aspiration pneumonia vary based on the site of acquisition (community-acquired aspiration pneumonia [CAAP] versus healthcare-associated aspiration pneumonia [HCAAP]), the risk for multidrug-resistant (MDR) organisms, and severity of illness. Hospitalized CAAP patients without severe illness and with no risk for MDR organisms or Pseudomonas aeruginosa (PA) can be treated with standard inpatient community-acquired pneumonia therapy covering anaerobes. Patients with CAAP and either of the following—risk factors for MDR pathogens, septic shock, need for an intensive care unit (ICU) admission, or mechanical ventilation—can be considered for broader coverage against anaerobes, methicillin-resistant Staphylococcus aureus (MRSA), and PA. Severe aspiration pneumonia that originates in a long-term care facility or HCAAP with one or more risk factors for MDR organisms should be considered for similar treatment. HCAAP with one or more risk factors for MDR organisms or PA, plus septic shock, need for ICU admission or mechanical ventilation should receive double coverage for PA in addition to coverage for MRSA and anaerobes. Multiple gaps in current understanding and management of aspiration pneumonia require future research, with a particular focus on antibiotic stewardship.