Understanding the Viscosity of Liquids used in Infant Dysphagia Management.
Jacqueline Frazier, Amanda H Chestnut, Arwen Jackson and 3 others
PMID 27412005WHAT IT FOUND
Most infant formulas and breastmilk remain thin after adding powdered barium, but Enfamil AR formulas and pre-mixed Liquid E-Z-Paque behave differently.
Check the exact product and preparation before assuming a thin liquid.
Key findings
01The 60% w/v pre-mixed Liquid E-Z-Paque barium is much more viscous than a 60% w/v suspension made from powdered E-Z-Paque, testing above 100 mPa.s and almost 6 times the powdered product.
02Adding 20% w/v barium to most infant formulas and breastmilk increased viscosity by about 3 mPa.s at 50s-1, with increases ranging from 0.2 to 1.3-fold, but the mixtures stayed below 12 mPa.s.
03Enfamil AR formulas were near or across the National Dysphagia Diet thin and nectar-thick boundary, with mean values between 44 and 76 mPa.s at 50s-1, and one product thinned while the other thickened after barium.
STILL TO COME
How it was doneWhat they foundWhat it means for SLPs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
The study measured liquids only, so it does not show how these products affect swallowing in infants. The National Dysphagia Diet viscosity categories are consensus based, and no viscosity boundary has been shown to cause a clear change in swallowing behavior. Small differences in viscosity may not have known clinical meaning. Breastmilk results came from only two donors, with no information about time post-partum, pumping time, or other factors, so they are very preliminary. Yield stress and density were not measured, and the reasons for variability in Enfamil AR products are unknown. Only E-Z-Paque barium and five infant formulas were tested.
Declared interests
The supplied metadata lists non-U.S. government research support. No author conflict-of-interest declaration is included in the text.
The easy way to misread this
Do not conclude that adding barium always keeps infant liquids thin or that barium products with the same brand and concentration behave alike. The pre-mixed Liquid E-Z-Paque was much thicker than the same concentration made from powder, and Enfamil AR formulas changed inconsistently after barium.