RESUMEN
OBJECTIVE: The response of the pharyngeal phase during swallowing is influenced by various factors including viscosity, shape, firmness, fracturability, and cohesive power. These factors affect the pharyngeal phase simultaneously, but little research has been conducted into their individual effects on the pharyngeal phase. This study investigated the relationship between controlled viscosity and pharyngeal transit time (PTT). METHOD: The subjects were 81 patients with naso-gastric tube due to brain dysfunction. PTT was assessed by video- esophageal fluoroscopy and the viscosity of the processed starch by Brookfield viscometer. High viscosity was defined as a controlled viscosity of 12% and 9%, medium viscosity as a controlled viscosity of 7.5%, 6%, and 4.5%, and low viscosity as a controlled viscosity of 3%, 1.5%, and 0% (liquid viscosity). RESULTS: PTT was prolonged with increasing viscosity in the experimental group. There were no significant differences between PTT of the experimental and control groups at any viscosity. Aspiration prevalence was 1.85%, 7.82%, and 22.22% in the high, medium, and low viscosity groups, respectively, and the three prevalences showed significant differences. CONCLUSION: PTT showed a tendency to be prolonged with increasing food viscosity in the experimental group.