Because any MBS study is a very brief sample of the patient’s swallow function, critical events, such as aspiration, may be missed unless they occur on every swallow. By extracting objective measures of timing and displacement associated with swallowing, the UC Davis Center has been able to develop predictive risk profiles. For instance, using a surrogate measure of pharyngeal strength called the pharyngeal constriction ratio, which is a comparison of the maximally constricted pharynx during a swallow to its fluoroscopic appearance when unconstricted [see Figs. 1 and 2, see p. 16], the team is able to assess a patient’s risk of aspiration even if it is not observed during the study.
Explore This IssueFebruary 2010
Tracking transit time of the bolus through the pharynx and hypopharynx has also allowed useful risk comparisons. A study of patients with acute stroke assessed with MBS showed a strong correlation between prolonged transit—swallows requiring two seconds or more—and readmission with aspiration pneumonia (Arch Phys Med Rehabil.1993;74(9):973-976).
Patients in the intensive care unit or nursing homes, for whom transport to the fluoroscopy suite is not possible, might not be candidates for MBS. It’s also generally avoided in children, for whom exposure to radiation should be minimized.
Keeping Testing In Office
Office-based FEES to assess patients’ oropharyngeal swallow offers portability, avoidance of radiation exposure and real-time visualization of pharyngeal structures. “I find it’s very helpful,” said Robert Stachler, MD, FACS, senior staff physician in the Department of Otolaryngology at Henry Ford Hospital in Detroit. Clinicians can assess patients’ response to positional maneuvers suggested by the speech pathologist and “get automatic feedback on what works and what doesn’t.”
The video “white-out period,” when the pharynx closes, is a minor disadvantage, but Dr. Stachler said clinicians can often infer whether there is aspiration and can look, if need be, to confirm their suspicions before proceeding with a treatment plan.
In addition to its utility as a first test to evaluate swallowing, FEES is also invaluable for monitoring patients after initiation of treatment, said Dinesh K. Chhetri, MD, assistant professor of head and neck surgery and director of the Swallowing Disorders Center at the David Geffen School of Medicine at the University of California, Los Angeles. “You can observe their swallowing and compare the findings to your older video recording,” he said. This allows for recommendations regarding diet and “really gives us a much better handle in taking care of our patients.”
Clinicians who suspect dysfunction in the esophageal phase of deglutition can reduce costs and recovery time by performing TNE in the office setting. Gregory Postma, MD, director of the Center for Voice and Swallowing Disorders at the Medical College of Georgia in Augusta, has been performing TNE for 10 years and reports a nearly 98 percent successful examination rate. TNE is “one of our best tools,” he emphasized.