The need for international terminology and definitions for texture-modified foods and thickened liquid used in dysphagia management: foundations of a global initiative

Conservative estimates suggest that dysphagia (difficulty swallowing) affects approximately 8 % of the world's population. Dysphagia is associated with malnutrition, dehydration, chest infection and potentially death. While promising treatments are being developed to improve function, the modification of food texture and liquid thickness has become a cornerstone of dysphagia management. Foods are chopped, mashed or puréed to compensate for chewing difficulties or fatigue, improve swallowing safety and avoid asphyxiation. Liquids are typically thickened to slow their speed of transit through the oral and pharyngeal phases of swallowing, to avoid aspiration of material into the airway and improve transit to the esophagus. Food texture and liquid modification for dysphagia management occurs throughout the world. However, the names, the number of levels of modification and characteristics vary within and across countries. Multiple labels increase the risk to patient safety. National standardization of terminology and definitions has been promoted as a means to improve patient safety and inter-professional communication. This article documents the need for international standardized terminology and definitions for texture-modified foods and liquids for individuals with dysphagia. Furthermore, it documents the research plan and foundations of a global initiative dedicated to this purpose

Thickening agents used for dysphagia management: effect on bioavailability of water, medication and feelings of satiety

Dysphagia is the medical term for difficulty swallowing. Thickened liquids are often used in the management of dysphagia to improve bolus control and to help prevent aspiration. A range of starches and gums has historically been used to thicken liquids. Although thickened liquids improve swallow safety, they appear to have a great potential for unintended physiological consequences. Initial concerns were raised about the impact of thickeners on water binding due to the high prevalence of dehydration amongst individuals with dysphagia. Thankfully, regardless of thickening agent, thickeners do not affect water bioavailability. This effect holds true even for extremely thick fluids. However, bioavailability of medication is impaired with viscous substances. Liquids thickened to as little as 150 mPa.s retards drug release. In addition, feelings of satiety and thirst increase with increasingly viscous fluids. Flavour deteriorates with increasing thickness regardless of thickening agent. Therapeutically clinicians often prescribe small volumes of thickened liquids, consumed often. Yet small volumes of thick substances consumed with a long oral processing time, which is common for individuals with dysphagia, reduces the amount consumed. A combination of poor flavour, and increasing feelings of fullness result in little motivation and poor physiologic drive to consume thickened liquids.This review provides evidence from the dysphagia, pharmaceutical and food technology literature to show unintended side effects of thickened liquids that contribute to dehydration and potential sub-theraputic medication levels for individuals with dysphagia. The physical property of viscosity rather than a particular thickening agent appears to be key. Provision of "spoon-thick" or "extremely thick liquids" is particularly likely to contribute to dehydration and poor bioavailability of solid dose medication. Clinicians are encouraged to prescribe the minimal level of thickness needed for swallowing safety. Consultation with pharmacy and dietetic staff is essential for optimum management of individuals with dysphagia. Given the aged population forecasts for the year 2050, improved dysphagia management should be a high priority