Using the BaByVFSS Impairment Profile to Characterize the Impact of Thin and Mildly Thick Liquid Consistencies on Validated Physiological Components of Swallowing in Bottle-Fed Children

Purpose: Thickening liquids is a common intervention to minimize aspiration despite limited understanding of how two different consistencies impact swallow physiology in babies. This investigation used the BaByVFSS Impairment Profile (BaByVFSSImP) to examine the influence of different liquid consistencies on validated physiological components of swallowing during bottle feeding. Method: Participants were bottle-fed thin and nectar-thick barium liquid (Varibar) during clinically indicated videofluoroscopic swallowing studies (VFSSs) at two study sites. Swallowing impairments were scored using the BaByVFSSImP. Demographic and clinical data, maximum Penetration–Aspiration Scale (PASmax) scores, Feeding/Swallowing Impact Survey (FS-IS) scores, and pre- and post-VFSS levels of feeding were collected. Results: Two hundred twenty-five babies (median age = 2.9 months, interquartile range = 1.1–7.1 months) with heterogeneous conditions participated. On the BaByVFSSImP, mildly thick liquid was associated with lower (better) impairment scores than thin for Domain 2 (Palatal-Pharyngeal Approximation, p = .02), Domain 3 (Airway Invasion/Laryngeal Closure, p < .0001), and Domain 4 (Aspiration, p < .0001). Domain 1 (Lingual Motion/Pharyngeal Swallow Initiation) and Domain 5 (Pharyngeal Transport and Clearance) did not differ by consistency. However, impairment scores with thick liquid were higher (worse) for Component 2 and lower (better) for Component 5. With mildly thick liquid, Domain 3 ( r s = .82, p < .001) and Domain 4 ( r s = .74, p < .001) had strong positive correlations with PASmax, while Domain 2 ( r s = .15, p = .02) and Domain 5 ( r s = .20, p = .003) had weak positive correlations with PASmax. Correlations between post-VFSS feeding recommendations and mildly thick liquid impairment scores for Domain 3 ( r s = .24, p < .001), Domain 4 ( r s = .31, p < .001), and Domain 5 ( r s = .13, p = .05) were significant. Domain scores did not significantly correlate with FS-IS subscales. Significantly greater volumes of thin liquid barium were administered compared to mildly thick barium at both study sites ( p < .001). Conclusions: Our findings demonstrate improved swallow physiology and airway protection with mildly thick compared with thin liquids in bottle-fed children with diverse diagnostic conditions. Additional studies are needed to guide clinical decisions about thickening liquids for individual and well-defined populations of children that take into account their diagnostic conditions and physiological impairment profiles and move beyond the limitations associated with Penetration–Aspiration Scale findings alone.