Measuring Viscosity and Consistency in Thickened Liquids for Dysphagia: Is There a Correlation Between Different...

Area of Science:

• Food Science
• Biomedical Engineering
• Clinical Nutrition

Background:

• Dysphagia (difficulty swallowing) is prevalent in older adults, increasing risks of malnutrition and aspiration.
• Thickening liquids is crucial for safe swallowing, but accurate viscosity measurement is challenging.
• Rotational rheometry is accurate but impractical for routine clinical or home use.

Purpose of the Study:

• To evaluate and correlate viscosity measurements of thickened liquids using empirical methods against rheological data.
• To assess the reliability of simple viscosity tests for dysphagia diet standardization.

Main Methods:

• Compared viscosity measurements from Ford cup, Bostwick consistometer, and Line-Spread Test (LST) with rotational rheometry.
• Tested various thickeners (guar gum, xanthan gum, blends, maltodextrin, commercial) at different concentrations, temperatures, and preparation times.

Main Results:

• Bostwick consistometer and LST showed strong correlations with rheometry for International Dysphagia Diet Standardisation Initiative (IDDSI) Levels 2 and 3.
• Limitations were noted for extreme viscosities, where some methods lacked sensitivity or feasibility.

Conclusions:

• Empirical viscosity measurement tools are viable for practical dysphagia management, especially when rheometry is unavailable.
• This study provides evidence for standardized fluid consistency assessment in dysphagia care.