Videofluoroscopic Analysis to Determine the Effects of Thickened Liquid on Oropharyngeal Swallowing Function in Infants with Respiratory Compromise

In clinical practice, infants who present with dysphagia during instrumental assessment are frequently placed on a diet that includes thickened liquids. There is scant empirical evidence available to support this common treatment practice. Studies that have previously attempted to evaluate the effectiveness of thickened liquids as a treatment option for infants with dysphagia have been limited by poorly defined physiologic parameters and small, heterogenous populations of study. The purpose of this dissertation was to systematically evaluate the effects of thickened liquids in a homogeneous sample of infants through retrospective analysis of archived videofluoroscopic swallow studies. Fifteen different temporal and physiologic measures were recorded from frame by frame analysis of 242 swallows selected from the videofluoroscopic swallowing studies of 25 infants with respiratory compromise. Each subject provided a sample of both thin and nectar thickened liquid swallows for comparison. In total, 121 swallows of thin liquid barium and 121 swallows of nectar thickened liquid barium were analyzed. Significant differences were found among the following variables between swallows of thin liquid barium and swallows of nectar thickened liquid barium: number of sucks per swallow, suck time, oral transit time, time to initiate velar movement, scores on the penetration-aspiration scale, location of the bolus before the swallow, and presence of residue after the swallow. There were greater numbers of sucks per swallow, longer suck and oral transit times, lower mean scores on the penetration-aspiration scale, and longer time to initiate velar movement for swallows of nectar thickened liquid barium as compared to swallows fo thin liquid barium. Bolus material collected at a more inferior location along the upper aerodigestive tract during swallows of the nectar thickened liquid barium. There was greater frequency of residue in the pharynx following swallows fo the nectar thickened liquid barium. The contribution of these variables to overall swallowing safety is discussed. Results point to improved swallowing safety with the use of nectar thickened liquids as a result of prolonging the oral phase of swallowing, thereby reducing the frequency of pharyngeal swallow and opportunities for airway compromise during bottle feeding