ABSTRACT
PURPOSE OF REVIEW: Thickened fluids are a widely utilised compensatory management strategy for people with impaired swallowing (dysphagia). Over recent years there has been a shift in practice to offer gum-based instead of starch-based products. A key marketing message has been that gum-based thickeners with amylase-resistant properties are superior in promoting 'safer swallowing'. This review sought evidence to evaluate the effect of amylase-resistant products on swallowing safety. RECENT FINDINGS: No studies directly compared the effect of amylase-resistant products with usual care or products without amylase resistance. Five studies cited amylase-resistant properties and compared gum-based to starch-based dysphagia products or thin fluids. Swallowing safety was frequently judged subjectively with rating scales. Swallowing biomechanics were not included and clinically meaningful outcomes, such as incidence of aspiration pneumonia, were not reported. A scoping review of the grey literature found little evidence that amylase-resistant properties of dysphagia products were of significant concern to clinicians or patients. SUMMARY: Despite references to the 'importance' of amylase-resistant properties of dysphagia products there is no evidence that this property improves swallowing safety. Further research is needed using objective and clinically meaningful outcome measures to allow clinicians and patients to make informed decisions for dysphagia management.
Subject(s)
Deglutition Disorders , Deglutition , Amylases , Beverages , Deglutition Disorders/etiology , Deglutition Disorders/therapy , Food Additives , Humans , Plant Gums , Pneumonia, Aspiration/prevention & control , StarchABSTRACT
Recent studies show that understanding the rheological properties of thickened fluids, such as viscosity and yield stress, is advantageous in designing optimal thickened fluids for the treatment of dysphagia. To date, these studies have focused on the rheological behavior of thickened fluids in shear deformation, while limited information is available on the surface tension of thickened fluids or their rheological behavior in extensional deformation. Knowledge of the extensional properties of thickened fluids (extensional viscosity and cohesiveness) is important to fully understand the behavior of such fluids while swallowing. Our aim in this work, therefore, was to characterize water and skim milk thickened with a commercial thickener (xanthan gum based) to determine extensional deformation and surface tension properties. It was observed that the surface tension decreases as the thickener concentration increases due to the accumulation of the biopolymer at the surface of the fluid when it dissolves in water. In addition, the extensional viscosity of the fluid increased over time as the filament thinned (i.e., as the Hencky strain increased) until it reached a plateau. It was observed that the maximum extensional viscosity, which is related to the cohesiveness of the fluid, increases with the higher concentrations of thickener. However, the cohesiveness of thickened skim milk was lower than that of the thickened water at a given thickener concentration due to lower surface tension. This study confirms that by increasing the concentration of thickener, it will not only increase the shear viscosity (i.e., bolus thickness) of the fluid, but also the extensional viscosity (i.e., bolus cohesiveness).
Subject(s)
Food Additives/pharmacology , Milk/chemistry , Rheology/methods , Surface Tension/drug effects , Viscosity/drug effects , Water/chemistry , Animals , Deglutition , Deglutition Disorders , Humans , Polysaccharides, Bacterial/pharmacologyABSTRACT
Objective rheological assessment of fluids given to dysphagic patients at mealtime and during videofluoroscopy was carried out using a multicenter format. Thin, quarter-thick, half-thick and full-thick fluids were examined for the degree of correlation between mealtime fluids and their allegedly matched videofluoroscopy counterparts. The study was carried out to determine whether perceived subjective differences between mealtime fluids and videofluoroscopy fluids could be quantified using the rheological parameters of viscosity, density, and yield stress. The results showed poor correlation between mealtime fluids and videofluoroscopy fluids over all parameters. In general, the videofluoroscopy fluids were more viscous, more dense, and showed higher yield stress values than their mealtime counterparts. Given these results, it is reasonable to assume that the fluids used during videofluoroscopy do not provide an accurate indication of swallowing ability at mealtime. Therefore, it is suggested that clinicians use objective methods to rheologically match videofluoroscopy fluids to mealtime fluids.
Subject(s)
Beverages , Deglutition Disorders/diagnosis , Viscosity , Fluoroscopy/methods , Humans , RheologyABSTRACT
This investigation examined the rheological (viscosity and yield stress) and material property (density) characteristics of the thickened meal-time and videofluorscopy fluids provided by 10 major metropolitan hospitals. Differences in the thickness of thickened fluids were considered as a source of variability and potential hazard for inter-hospital transfers of dysphagic patients. The results indicated considerable differences in the viscosity, density, and yield stress of both meal-time and videofluoroscopy fluids. In theory, the results suggest that dysphagic patients transferred between hospitals could be placed on inappropriate levels of fluid thickness because of inherent differences in the rheology and material property characteristics of the fluids provided by different hospitals. Slowed improvement or medical complications are potential worst-case scenarios for dysphagic patients if the difference between the thick fluids offered by 2 hospitals are extreme. The investigation outlines the most appropriate way to assess the rheological and material property characteristics of thickened fluids. In addition, it suggests a plan of quality improvement to reduce the variability of the thickness of fluids offered at different hospitals.
Subject(s)
Deglutition Disorders/diagnosis , Deglutition Disorders/therapy , Fluoroscopy/methods , Hospitalization , Humans , Rheology , Viscosity , WaterABSTRACT
A hypothetical discussion of the cause of swallowing sounds is presented. It is suggested that the pharynx contains a number of valves and pumps that produce reverberations within the pharynx to generate swallowing sounds. As heart sounds are propagated via vibration of muscles and valves, it is further suggested that an analogy exists between the generation of heart sounds and swallowing sounds. This new theory is known as the cardiac analogy hypothesis. The inability of the current literature to explain the cause of swallowing sounds is seen to limit the diagnostic potential of cervical auscultation for dysphagia assessment. Future investigators are encouraged to prove or disprove the cardiac analogy hypothesis.
Subject(s)
Acoustics , Deglutition/physiology , Heart Murmurs/diagnosis , Sound , Vocal Cords/physiology , HumansABSTRACT
In 1955, the area infested by Aedes aegypti in Argentina was estimated as 1,500,000 km2; and in 1963, the species was considered to be eradicated from Argentina. In 1995, the Argentine Ministry of Health reported reinfestation by Ae. aegypti. During 1994-95, the Ministry of Health of Córdoba Province, Zoonosis Department, established a surveillance system for Ae. aegypti in Córdoba Province, Argentina. This report is a summary of results obtained thus far. In total, 74 localities in Córdoba Province were sampled during August 1994-April 1996, resulting in 5 positives (6.7%): Villa María city, Villa Nueva, and Córdoba city in 1995, and Juarez Celman and Jesús María in 1996. In Villa María and Villa Nueva, Ae. aegypti was present until June 1995 (autumn) and reappeared in December 1995. In Córdoba city, Ae. aegypti was eliminated from the only positive house in May 1995, but it reappeared in March 1996. Reappearance of Ae. aegypti in this temperate area in early summer may have been due to the survival of individuals during winter and not to reintroduction during summertime. The last previous active surveillance for Ae. aegypti in Córdoba Province was carried out more than 30 years ago.
Subject(s)
Aedes , Animals , Argentina , TemperatureABSTRACT
Aspectos epidemiológicos de la tripanosomiasis americana en la Argentina. Organigrama del servicio nacional de enfermedades de chagas
Subject(s)
Humans , Animals , Chagas Disease , Epidemiology , Health Programs and Plans , National Health Programs/organization & administration , Argentina , Communicable Disease Control , Chagas Disease/history , Cross-Sectional Studies , National Health Programs/history , Disease Reservoirs , Triatoma/classification , Triatoma/parasitology , Disease Vectors/classificationABSTRACT
Aspectos epidemiológicos de la tripanosomiasis americana en la Argentina. Organigrama del servicio nacional de enfermedades de chagas
Subject(s)
Humans , Animals , Chagas Disease , Epidemiology , Health Programs and Plans , National Health Programs/organization & administration , Triatoma/classification , Triatoma/parasitology , Disease Reservoirs , Disease Vectors/classification , Cross-Sectional Studies , Communicable Disease Control , National Health Programs/history , Argentina , Chagas Disease/historyABSTRACT
Se considera el estado presente y las perspectivas para el control químico de la enfermedad de Chagas, destacándose la necesidad de que éste se ensamble dentro de un programa de enfoque integral e integrado, y de que cambie la metodología operativa empleada hasta el momento. se evalúan resultados de la aplicación de los diversos insecticidas disponibles, la acción toxica de los mismos, así como costos, ventajas y desventajas de cada tipo de compuesto. Se informa sobre hexaclorociclohexanos (HCH, BHC); Dieldrin; Propoxur (carbamato); los insecticidas fosforados y organofosforados Mercaptothión, Fenitrothión, Clorpirifos, DDVP o Vapoma o Diclorvos, Diazinón, Fenthion; el insecticidas gaseoso Bromuro de metilo; las piretrinas o piretroides permetrina y decametrina; el Metyl-pirimiphos; el Jodfenphos; Bromophos; Bendicarb; Deltamethrin; e insecticidas de liberación lenta. Se mencionan los parásitos de triatominos estudiados -esoecialmente el Telenomus fariai- y su valor paa el control biológico de triatominos, considerándose que no es posible el control de los mismos por manipulaciones genéticas
