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BACKGROUND/RATIONALE:
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. VA vendors estimate the VA will spend 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 recently was appointed to provide evidence-based recommendations for the use of thickened liquids in VA hospitals nationwide. Recent 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). This trial enrolled 742 subjects who underwent a videofluoroscopic swallowing study (VFSS) using Varibar Thin (<15 cps*), Nectar-thick (300 cps), and Honey-thick (3000 cps) barium. Results indicate that significantly more patients aspirated on thin barium than on nectar-thick (68% vs. 63%) or honey-thick barium (68% vs. 53%). However, significantly fewer patients rated honey-thick 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).
OBJECTIVE(S):
The goal of this multidisciplinary pilot project, which is an urgent follow-up study to the recently completed multi-site randomized clinical trial, is 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 will be accomplished by four objectives listed in the Methods section as outlined in the subsequent timeline.
METHODS:
110 males and females (in- and out-patient stratification) scheduled for a standard clinical videofluoroscopic swallow study (VFSS) will be recruited from the Madison VA and the University of Wisconsin Hospitals, which receive over 2000 outpatient dysphagia referrals annually, to achieve equal gender representation and permit sufficient accrual within the limited time frame of this funding mechnanism. Inclusion criteria are: (1) aspiration of thin liquid confirmed with VFSS; (2) mental capacity to provide consent; and (3) over age 45 years. A sample size of 110 subjects provides 80% power to detect a difference between an aspiration rate of 60% with thin honey and 53% with honey-thick using McNemar's test with a two-sided 5% level, assuming the within-subject correlation is 0.86.
Aim 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 - will be measured for each barium material used in this project. This will form the basis for scientific design and implementation of an effective range of diagnostic and treatment fluids.
Aim 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 will be determined for each swallow completed during a standard VFSS, as follows:
(a) Potential subjects will be given 3 boluses of Varibar Thin Liquid (<15 cps) in 3-mL and selfadministered amounts. If aspiration is observed, the patient will be enrolled in the study and will continue with Steps b-c. If no aspiration is observed, the patient will complete the evaluation per standard of care.
(b) Subjects who enroll in the study will be administered Varibar Nectar-thick (300 cps) barium in 3-mL and self-administered amounts. If aspiration is observed, the subject will proceed to Step c. If no aspiration is observed, the patient will complete the evaluation per standard of care.
(c) Subjects will be administered, in random order, 3 boluses of Varibar Thin Honey (1500 cps) and Varibar Honey (3000 cps) barium in 3-mL and self-administered amounts.
(d) Lingual pressures will be obtained from all subjects advancing to step (c) 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.
Aim 3: To test patient preference and perception of barium materials. Subjects will complete preference ratings3 after each swallow during the VFSS and a 10-minute sensory analysis questionnaire about the flavor, "mouth feel," and visual perception of each of the barium materials.
Aim 4: To disseminate findings and develop a plan for implementing and evaluating a defined range of thickened fluids. Following data collection, analysis, and interpretation, a Satellite Videoconference will be held with a multidisciplinary group of leaders from the VA Office of Research and Development and the OIG-appointed VA Nutrition & Food Service and Speech Language Pathology Joint Task Force.
The purpose of this conference is to disseminate project results, assess feasibility for translation into clinical practice (e.g., access to materials for in- and out-patients), and develop a plan for implementing and evaluating a re-defined range of thickened fluids for dysphagia treatment. These leaders, representing the disciplines of Geriatrics, Neurology, Speech Language Pathology, and Nutrition & Food Service, have confirmed their conviction of the need to garner evidence that may guide best practice in this domain and have expressed enthusiastic support for this proposed project as a necessary step in that direction.
FINDINGS/RESULTS:
No results at this time.
IMPACT:
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 E-Z-EM, 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.
PUBLICATIONS:
None at this time.
DRA:
Chronic Diseases
DRE:
Treatment, Quality of Care, Prevention
Keywords:
Adverse events, Patient outcomes, Care Management
MeSH Terms:
none
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