QUANTITATIVE ASSESSMENT OF SWALLOWING IN HEALTHY-ADULTS

Swallowing has hitherto been evaluated during physical examination, ra diologic barium studies, manometry, and cervical auscultation. Radiogr aphy principally demonstrates qualitative aspects of oral and pharynge al function, whereas quantitative aspects have primarily been document ed by manometry. To evaluate swallowing quantitatively, without using invasive methods or radiation, we have applied a combined test of wate r drinking, i.e., the Repetitive Oral Suction Swallow test (ROSS). The test provides reliable measurements of suction pressure, bolus volume , timing of important events in oral and pharyngeal swallow, and respi ration. The test is described and results from 292 healthy, non-dyspha gic subjects are presented. We found a mean bolus volume of 25.6 +/- 8 .5 mi during single swallow and 21.1 +/- 8.2 mi during stress (forced, repetitive swallow). During forced, repetitive swallow, the bolus vol ume was more strongly associated with suction time (r(2) = 0.55) than with peak suction pressure (r(2) = 0.04), indicating that suction time is more important than suction pressure in determining the bolus volu me. The oral-pharyngeal transit time decreased: single swallow 0.56 +/ - 0.36 sec, forced repetitive swallow 0.23 +/- 0.11 sec, as did the co efficient of variation (48% and 64%, respectively) indicating a more a utomatic neural process for pharyngeal function in forced, repetitive swallow. The postswallow respiration started with inspiration in 10% o f studied individuals, but did not correlate with deviations in other variables in the test. Thus, postswallow inspiration must be considere d as normal. The ROSS test offers a rapid and easy quantitative assess ment of swallowing.