The Relationship between Aspiration and Pneumonia Following Stroke

Abstract

Aspiration is defined as entry of oral material into the airway below the level of the true vocal cords. Aspiration is common following stroke, particularly in the initial acute phase. Because a significant number of these aspirators are “silent aspirators,” videofluoroscopic modified barium swallow (VMBS) studies are regarded as necessary to definitively diagnose aspiration in stroke patients. Pneumonia or chest infections occur relatively frequently more following stroke; they are most common shortly after stroke onset. The incidence of pneumonia varies according to clinical criteria and the populations studied. Nevertheless, a strong association between aspiration and pneumonia has been established with a 7-fold or greater risk of pneumonia among aspirators when compared with non-aspirators. Factors associated with aspiration pneumonia are the degree of severity of aspiration and—to a lesser extent—the underlying susceptibility of the stroke patient’s lungs.