New diet guidance for those suffering dysphagia

Oct 24 2007

Research at Wake Forest University Baptist Medical Center is leading to potentially lifesaving changes for patients suffering from dysphagia, or swallowing difficulty.

Dysphagia is common among critical care patients and can lead to malnutrition, aspiration of food or liquids into the trachea, and pneumonia.

The study was presented at the American College of Chest Physicians meeting in Chicago. It examined the National Dysphagia Diet (NDD) guidelines established by the American Dietetic Association in 2002 and compared these guidelines to prepared dysphagia diet foods (DDFs) given to patients. The NDD provided guidelines for selecting the viscosity of foods given to patients with dysphagia.

The researchers tested foods that ranged in thickness from “thin” to “nectar” (thicker) to “honey” (thickest), using the NDD terminology. They found that of four different prepared DDFs used at the Medical Center – Resource, Hormel, Carnation and Boost – the viscosity listed for Resource was the most consistent with NDD guidelines.

“Currently, there is no published research comparing the NDD guidelines to dysphagia diet foods,” said Lindsay Chaney Strowd, a medical student at Wake Forest Baptist and the principal investigator. “The NDD guidelines were established with the expectation that dysphagia diet foods would be manufactured with specific viscosities consistent with the NDD guidelines. We found that this isn't the case.”

The researchers also evaluated barium test liquids used at the Medical Center to determine if their viscosities correlated with their dysphagia diet counterparts. The liquids are used to diagnose patients with dysphagia through a test called a barium swallow study. Patients are given barium liquids that, like the DDFs, are assigned a viscosity of either thin, nectar or honey. The barium can be seen on an x-ray, allowing a radiologist to detect if any of the liquids are aspirated into the trachea. Physicians use those results to determine which viscosity of DDFs to feed to patients.

The researchers found that barium test liquids currently used at the Medical Center, and probably at many other institutions, are actually designed for lower gastrointestinal studies, not barium swallow studies, making it impossible to compare them.

“The barium products being used in barium swallow studies are thixotropic, meaning they are designed to thicken and coat the walls of the intestine,” said Strowd. “This coating nature is the opposite desired effect of barium swallows. These products are probably used because they are inexpensive and already available, and there have not been alternative barium products in the past.”

As a result of these findings, Wake Forest Baptist changed to a newer line of products that are specifically designed for barium swallow studies and come premixed, unlike the original products that required thickeners to be added to create the desired viscosity.

Due to each of these findings, the American Dietetic Association is developing new NDD guidelines, and has asked Julie Bradshaw, one of the speech and language pathologists who served as an advisor on the study, to participate.

“This study is so significant because it is rare that a research project takes it from bench to bedside in just a few months,” said Strowd. “We identified a problem, researched the mechanisms underlying the problem, and recommended specific, concrete solutions.”

“Anyone who provides care wants to do the absolute best job they can. They want to take the best information that's available and use it. We were doing a great job following the guidelines, but we were still seeing problems,” said Bruce Rubin, M.D., M.Engr., M.B.A., a professor of pediatrics and senior advisor on the study. “That's why it's important to rethink the tests for dysphagia, how the results are used, and how it makes a difference for patients.”

“This will potentially help institutions across the country offer better testing and treatments to their patients,” said Susan Butler, Ph.D., C.C.C.-S.L.P., assistant professor of otolaryngology and an advisor on the study. “Patients at Wake Forest Baptist are fortunate to be on the cutting edge of such innovative work.”

This study was co-sponsored by the Society for Pediatric Research and the North Carolina Baptist Hospital Six Sigma initiative.

Wake Forest University Baptist Medical Center is an academic health system comprised of North Carolina Baptist Hospital and Wake Forest University Health Sciences, which operates the university's School of Medicine. The system comprises 1,154 acute care, psychiatric, rehabilitation and long-term care beds and is consistently ranked as one of “America's Best Hospitals” by U.S. News & World Report.