Flow Rates of Bottle Nipples/Teats With Different Thicknesses of Barium and Infant Formula

The aim of this study was to evaluate the bottle nipple flow rate of liquid barium sulfate of three different International Dysphagia Diet Standardisation Initiative (IDDSI) thicknesses (i.e., thin, slightly thick, and mildly thick) and compare flow rates of infant formula thickened with Gelmix or oatmeal cereal to comparable thicknesses. Liquid preparations were IDDSI flow tested to determine thickness. Nipple flow rate testing was conducted using 50 ml of liquid in a 4-oz Dr. Brown's bottle with the venting system in place. Liquid was extracted using a breast pump. The weight of liquid extracted was converted to flow in milliliters per minute using the density of the liquid in grams per milliliter. Across nipple types and liquid thicknesses, the flow rate through the bottle nipple with formula was faster than with barium of the same thickness. Thickening with oatmeal cereal resulted in clogging of the nipple. Pulverizing the oatmeal did not improve clogging but did impact caloric density of the formula. Bottle nipple flow rates of liquid barium sulfate are not consistent with flow rates of thin infant formula or formula thickened with Gelmix to the same IDDSI thickness. These findings may impact the safety of oral feeding for some infants. Parents and clinicians need to be aware of clogging with oatmeal cereal as a factor that could contribute to variability in flow as well as difficulty extracting fluid for nutrition.