Scintigraphic detection of salivary aspiration: description of a new diagnostic technique and case reports

Pneumonia is the feared consequence of persistent aspiration of saliva. Although some persons with impaired protection of the laryngeal airway are thought to be at risk, it is not known with certainty which factors are important. Some patients receive tracheostomies to enhance airway safety, often without clear evidence of aspiration of oropharyngeal secretions. A simple, readily available technique is described by which oral secretions are scintigraphically labeled with technetium-99m sulfur colloid via slow intraoral infusion. Subsequent sequential chest imaging with a gamma camera allows detection and tracking of the aspirated material. Three persons are described in whom this technique was used. In one, the scintigraphic analysis was instrumental in implicating infected saliva as the likely source of recurrent pulmonary infections. Although the method is useful in detecting aspiration of saliva in high risk persons, more study is needed to equate the degree of aspiration visualized with the risk of pulmonary disease.