Incremental Adjustments to Amount of Thickening Agent in Beverages: Implications for Clinical Practitioners Who Oversee Nutrition Care Involving Thickened Liquids

Getting the consistency right in thickened liquids using Viscgo Sticks: A validation study

BACKGROUND

Dysphagia is a condition whereby a person's ability to swallow, eat and drink is impacted. One strategy to manage dysphagia and aid safe swallowing is the modification of food and drink, including using thickening agents to thicken drinks. Drinks are thickened to levels appropriate to a person's swallowing abilities and the underutilised 'syringe flow test' is currently the recommended method for checking thickness levels. Viscgo Sticks were developed as a practical alternative to the flow test.

METHODS

This is a real-world validation study designed to determine validity and reliability of Viscgo Sticks. Independent researchers and healthcare professionals tested Viscgo Sticks (Viscgo Limited) against the flow test in three levels of thickened drinks. Researchers also conducted tests with different thickening agents and different drink types: water, milk, orange juice and hot tea.

RESULTS

The intra- and inter-rater reliability of Viscgo Sticks was moderate to almost perfect (κ = 0.45-0.98) within and between researchers and substantial (κ = 0.66-0.67) within and between healthcare professionals. When tested by researchers and healthcare professionals against the flow test, Viscgo Sticks correctly classified 83.33%-100% of thickened drinks with high accuracy (area under curve = 0.70-1.00).

CONCLUSIONS

A simple and reliable tool like Viscgo Sticks, which can verify a prescribed thickness level of liquid, is invaluable in healthcare settings where day-to-day drink preparation occurs. Overall, Viscgo Sticks provide a reliable and valid means to test thickened drinks in clinical practice with a few exceptions identified.

Rheological Properties and Stability of Thickeners for Clinical Use

The adaptation of liquids for patients with dysphagia requires precision and individualization in the viscosities used. We describe the variations of viscosity in water at different concentrations and evolution over time of the three compositions of commercial thickeners that are on the market (starch, starch with gums, and gum). By increasing the concentration in water, the viscosity of gum-based thickeners increases linearly, but it did not reach pudding texture, whereas the viscosity of the starch-based thickeners (alone or mixed with gums) rapidly reaches very thick textures. We modeled the viscosity at different concentrations of the four thickeners using regression analysis (R2 > 0.9). We analyzed viscosity changes after 6 h of preparation. The viscosity of gum-based thickeners increased by a maximum of 6.5% after 6 h of preparation, while starch-based thickeners increased by up to 43%. These findings are important for correct handling and prescription. Gum-based thickeners have a predictable linear behavior with the formula we present, reaching nectar and honey-like textures with less quantity of thickener, and are stable over time. In contrast, starch thickeners have an exponential behavior which is difficult to handle, they reach pudding-like viscosity, and are not stable over time.

Instrumental and sensory techniques to characterize the texture of foods suitable for dysphagic people: A systematic review

The interest to characterize texture-modified foods (TMFs) intended for people with oropharyngeal dysphagia (OD) has grown significantly since 2011. Several instrumental and sensory techniques have been applied in the analysis of these foods. The objective of the present systematic review was to identify the most appropriate techniques, especially for the food industry and clinical setting. The search was carried out in three online databases according to the "Preferred Reporting Items for Systematic Reviews and Meta-Analyses" (PRISMA). Across the multiple trials reviewed, Texture Profile Analysis and the Uniaxial Compression Test were most used as the instrumental technique for solid foods, and the Back Extrusion Test for fluid and semisolid foods. All trials used descriptive analysis as the sensory technique. However, the experimental conditions of the trials lacked standardization. Consequently, the results of the trials were not comparable. To properly characterize the texture of TMFs intended for OD by each technique, an international consensus is needed to establish standardized experimental conditions. Methods based on these techniques should also be validated by collaborative studies to verify repeatability, replicability, and reproducibility.

Thickened liquids for dysphagia management: A call to action in the development of educational and instructional strategies

This article is a "call to action" in the service delivery of thickened liquids. We discuss the importance of staff education and further development of educational resources in dysphagia management involving the use of thickened liquids, particularly as related to inadequacies in staff education and training. We discuss the use of contemporary instructional strategies to promote accuracy in preparation and knowledge about the thickening process.

Thickened liquids: do they still have a place in the dysphagia toolkit?

PURPOSE OF REVIEW

The use of commercially or naturally thickened liquids is a well-established treatment for patients with dysphagia to fluids, the aim of which is to improve swallow safety by minimizing risk of aspiration. Although the most recent systematic reviews conclude that this treatment lacks evidential support and leads to patient-reported worsening health and quality of life, thickened liquids continue to be used with patients with dysphagia across clinical settings. This review briefly summarizes the evidence and considers potential reasons for the apparent mismatch between the evidence and clinical practice.

RECENT FINDINGS

Continuing practice with thickened liquids is influenced by a range of factors, including gaps in clinical knowledge, inadequate patient involvement, a culture of common practice and a reliance on invalid surrogate studies or research lacking a credible association between thickened liquids and clinically meaningful endpoints.

SUMMARY

While awaiting further research, clinical decision-making about thickened liquids can be improved by considering the evidence of clinically meaningful endpoints, promoting shared decision-making with patients and underpinning practice with knowledge about the complex relationship between dysphagia, aspiration and pneumonia.