Aspiration Syndromes

Abstract

Aspiration is defined as the misdirection of oropharyngeal or gastric contents into the larynx and lower respiratory tract. An assortment of pulmonary syndromes may occur following aspiration depending on the quantity and nature of the aspirated material, the frequency of aspiration, as well as the nature of the host’s defense mechanisms and the host’s response to the aspirated material. The most important syndromes include (1) aspiration pneumonitis, or Mendelson’s syndrome, which is a chemical pneumonitis caused by the aspiration of gastric contents, and (2) aspiration pneumonia, an infectious process caused by the aspiration of oropharyngeal secretions colonized by pathogenic bacteria. While there is some overlap between these two syndromes, they are distinct clinical entities (Table 11-1). Other aspiration syndromes include airway obstruction, lung abscess, exogenous lipoid pneumonia, chronic interstitial fibrosis, and Mycobacterium fortuitum pneumonia.