Dose-response Effect of the Thickener Tsururinko Quickly

Thickening fluids are a valid therapeutic strategy to improve safe swallowing in OD. The aim of this study is to assess the percentage of safe swallowing at different viscosity levels thickened with Tsururinko Quickly.

This study is designed to assess the therapeutic effect on safety and efficacy of swallow of Tsururinko Quickly for the levels of viscosity 100, 200, 400, 800, 1600mPa·s against thin liquid and between all the viscosity levels in older patients with Oropharyngeal Dysphagia (OD) by performing a Videofluoroscopy when swallowing. As all patients will start with thin liquid, each patient will be its own control. To analyze the effect of the salivary amylase on the thickener, participants will be asked to maintain two boluses (200 and 800mPa·s) prepared jut with mineral water in the oral cavity for 30seconds. After that period, boluses will be analyzed by a viscometer and compared to those without oral incubation.

Older patients, who fulfil the eligibility criteria, are invited to participate in the study. After having signed informed consent, participants who meet the inclusion and exclusion criteria will a screening procedure (V-VST). Viscosities for the V-VST: \<50, 200mPa·s and 800mPa·s. Two questions will be performed to the patient on palatability and acceptability. Palatability will be assessed by the 5-points hedonic scale and acceptability with the Scorecard - Food Action Rating Test. After it, a Videofluoroscopy (VFS) will be performed. For the VFS, participants will swallow 10mL boluses (by duplicate) of thin liquid and 5 different thickened viscosities of Tsururinko Quickly (1600, 800, 400, 200 and 100 mPa·s) with a stablished safety rule: when the subject aspirates at the first bolus of thin liquid, the second volume will not be given and the measurements will continue with the thickened varieties to the thinnest viscosity. In case the subject aspirates at one thickened bolus, the VFS ends for this specific patient. As all patients will start with thin liquid, each patient will be its own control with the non-thickened viscosity vs the others in order to establish the safety of swallow for all the levels performed. Patient's swallow will be studied with VFS in a lateral projection and images will include the oral cavity, pharynx, larynx and cervical oesophagus. After each bolus, the patient will be asked to give their opinion on the palatability of this specific bolus.

Before VFS, a bolus of 200 and 800mPa·s (without contrast) will be given to the participant in order to perform the oral incubation analysis. Participants should keep the bolus in their mouth for 30" and then spit it out. The bolus is then analysed with the viscometer at the shear rate of 50s-1 (estimated value at the oral cavity) and 300s-1 (estimated value at the pharynx). Viscosity values will be compared to the viscosity values without oral incubation. The day after the completion of the VFS participants will be asked by phone for AE.

Eligibility Criteria:
Inclusion Criteria:

* Age ≥70 years
* Oropharyngeal Dysphagia: clinical signs or symptoms of swallowing dysfunction (safety or efficacy impairments), based on videofluoroscopy (VFS)
* Written informed consent

Exclusion Criteria:

* No clinical signs or symptoms of swallowing dysfunction, based on videofluoroscopy (VFS)
* OD due to structural alterations
* Severe cognitive disorders or Investigator's uncertainty about the willingness or ability of the patient to comply with the protocol requirements and instructions
* Not able to undergo VFS due to incapability of sitting posture
* Pregnancy and/or lactating
* Allergy to any ingredient of test product or iodine products