List the common pathogens.
Gram-positive and gram-negative aerobic bacteria predominate in community-acquired infections (e.g., S. pneumonia, S. aureus, H. influenza, Enterobacteriaceae).
Gram-negative bacilli predominate in hospital-acquired infections (e.g., P. aeruginosa, Klebsiella spp.).
Mixed infections with anaerobic organisms may occur (e.g., Fusobacterium, Peptostreptococcus, Bacteroides).
List risk factors for aspiration.
(predispose individuals to reduced epiglottic gag reflex and dysphagia)
Altered consciousness: alcohol, sedation, general anesthesia, stroke
Apoplexy and neurodegenerative conditions
Gastroesophageal reflux disease, esophageal motility disorders
Congenital defects (e.g., tracheoesophageal fistula)
Use of a nasogastric feeding tube