Over 47% of veterans receiving health care from the Department of Veterans Affairs (VA) are over age 65. It is estimated that the number of veterans over age 85 will reach 1.4 million in 2012, a 167% increase since 2000. As the aging veteran population grows along with the U.S. population, dysphagia and associated health consequences (dehydration, malnutrition, pneumonia) have become national health care concerns. More than 270,000 veterans with dysphagia accounted for 350,000 visits and admissions to VA facilities in 2000. One of the most common treatments for dysphagia is thickening liquids, thereby modifying swallowing physiology by altering fluid rheology. In certain circumstances (e.g., neurodegenerative conditions such as dementia), it is not uncommon for thickened liquids to be recommended as a long-term solution for safe hydration. It was estimated that VA vendors spent nearly $1 million on thickened liquids in 2007. Considering the costly impact of dysphagia on veterans and in response to a directive from the Office of the Inspector General (VA Directive 2006-032, 5/17/06), a Nutrition & Food Service and Speech Language Pathology Joint Task Force was appointed to provide evidence-based recommendations for the use of thickened liquids in VA hospitals nationwide. Findings from the largest NIH-funded, multi-site randomized clinical trial for dysphagia provide the highest level of evidence available demonstrating the effects of thickened liquids for preventing liquid aspiration in the short-term and pneumonia in the long-term (3 months). That trial enrolled 742 subjects who underwent a videofluoroscopic swallowing study (VFSS) using Varibar Thin (<15 cps), Nectar (300 cps), and Honey (3000 cps) barium. Results indicated that significantly more patients aspirated on thin barium than on nectar (68% vs. 63%) or honey barium (68% vs. 53%). However, significantly fewer patients rated honey barium as "easy" or "pleasant" to swallow compared with the other interventions. Moreover, a 3-month follow-up of subjects randomly assigned to use one of the interventions revealed that of those hospitalized for pneumonia, subjects drinking honey-thick liquids were hospitalized an average of two weeks longer than subjects drinking nectar-thick liquids (median =18 versus 4 days).
The goal of this multidisciplinary pilot project was to measure the dose-response of a range of barium materials used for dysphagia diagnosis and treatment planning, thereby guiding implementation and programmatic evaluation of an intermediate intervention dose of thickened fluids. The goal was to be accomplished by four objectives:
Objective 1: To define rheological parameters influencing bolus flow for a representative range of barium materials. Apparent viscosity defined at the shear rate of fluid during swallowing is a single-point representation of a multi-parameter rheological fluid. To better understand the properties that influence bolus flow, and therefore can be manipulated to reduce airway invasion, more detailed rheological properties -such as yield stress, consistency coefficient, and shear-thinning exponent, in addition to apparent viscosity - were measured for each barium material used in this project. This formed the basis for scientific design and implementation of an effective range of diagnostic and treatment fluids.
Objective 2: To determine bolus flow kinematics for a range of barium materials, as they relate to lingual pressure. Direction and completeness of bolus flow (Penetration/Aspiration Scale; Residue Scores) in response to dosage were determined for each swallow completed during a standard VFSS.
Objective 3: To test patient preference and perception of barium materials. Subjects completed preference ratings after each type of barium during the VFSS.
Objective 4: To disseminate findings and develop a plan for implementing and evaluating a defined range of thickened fluids.
Twenty-five subjects (in- and out-patient stratification) scheduled for a standard clinical videofluoroscopic swallow study (VFSS) were recruited from the Madison William S. Middleton Memorial VA Hospital. Inclusion criteria were: (1) aspiration of thin and nectar liquid confirmed with VFSS; (2) mental capacity to provide consent; and (3) over age 45 years.
Potential subjects were given 3 boluses of Varibar Nectar Liquid (300 cps) in 3mL and self-administered amounts. If no aspiration was observed, the patient completed the evaluation per standard of care. If aspiration was observed, the patient was enrolled in the study and continued.
Subjects who enrolled in the study were administered Varibar Nectar (300 cps) barium in 3mL and self-administered amounts. If no aspiration was observed, the patient completed the evaluation per standard of care. If aspiration was observed, subjects were administered, in random order, 3 boluses of Varibar Thin Honey (1500 cps) and Varibar Thick Honey (3000 cps) barium in 3mL and self-administered amounts.
Lingual pressures were obtained from all subjects who were given Varibar Thin Honey during a static lingual press and dynamic saliva swallow using the Iowa Oral Performance Instrument (IOPI), a pressure-sensing device. Lingual pressure generation has been shown to influence bolus flow and is a promising target for more active treatments that, when paired with thickened liquids, may advance dysphagia recovery.
Detailed reports can be found in the Results section of the Narrative. The primary preliminary conclusion from this study was that the thin honey barium (1500cps) is equivalent to thick honey barium (3000cps) in terms of Penetration/Aspiration Scores and post-swallow residue in adult males with varied etiology of dysphagia. This is a potentially very positive outcome but its maximum benefit to patients would best be determined with longer term health status data obtained from patients for whom the 1500 cps honey is recommended as an optimal treatment for thin liquid aspiration.
Concern about long-term impact of honey-thick liquids on patient health and quality of life indicates an urgent need for a less-viscous honey fluid to manage dysphagia, and requires increased understanding of additional material properties relative to bolus flow, patient preference, and treatment outcomes. This need coincides with the recently available Varibar Thin Honey (1500 cps) by Bracco Diagnostics, Inc., which provides an intermediate dose and has implications for the widespread implementation of a broader range of dysphagia diagnostic and treatment fluids. The 1500 cps level has not been tested for comparison with the other standard levels (300 cps, 3000 cps) to determine the rheological properties, beyond apparent viscosity, that influence bolus flow, the biophysical effectiveness for reducing aspiration in patients who are known aspirators of thin (<15 cps) liquids, and patient preferences influencing treatment planning.
External Links for this Project
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