Thickening fluids for pediatric patients with Dysphagia: the challenge of achieving safe viscosities

Abstract

Speech-language pathologists (SLPs) at our hospital currently rely on their best clinical judgment to establish a nectar viscosity for bottle feedings because rheological equipment is not readily available. Therefore, clinicians use a 3:1 ratio of infant formula and/or breast milk to oat cereal to achieve a nectar viscosity. The main purpose of this study was to use a cone and plate rheometer to objectively quantify the viscosity of the five-thickened bottle-feeding conditions currently used at our hospital: infant formulas (19, 22, and 24 calorie) and breast milk (alone and a 50:50 mixture with 22-calorie formula) in a 3:1 ratio with oat cereal. A second goal was to determine the effects of time (over a 30-minute feeding duration) at body versus room temperature on viscosity outcomes for each thickened liquid condition. Results revealed that none of the thickened liquid bottle feeding conditions consistently remained in the nectar thick viscosity range. Specifically, several trials for each of the three thickened infant formula recipes rose above the nectar limit (i.e., into the honey thick range), whereas both thickened breast milk recipes (with and without 22-calorie formula) fell below the nectar limit (i.e., into the thin liquid range). Outcomes were significantly affected by temperature, but in an inverse manner for the three formulas (i.e., higher at body temperature) versus two breast milk (i.e., lower at body temperature) conditions. We are currently adjusting the 3:1 ratio for each of these conditions to achieve reliably stable low and high viscosity levels in the nectar thick range throughout a 30-minute feeding duration. Our ultimate goal is to standardize the viscosity of thickened liquid bottle feedings for infants across all levels of care for improved health care outcomes.