Background: Infant videofluoroscopic swallow studies (VFSSs) require clinicians to make determinations about swallowing deficits based on a limited number of fluoroscopically observed swallows. Although airway protection is known to decline throughout a bottle-feed, the paucity of data regarding the timing of this degradation has limited the development of procedural protocols that maximize diagnostic validity.
Objective: We tested the stability of key components of swallow physiology and airway protection at four standardized timepoints throughout the VFSS.
Materials and methods: Thirty bottle-fed infants with clinical signs of swallow dysfunction underwent VFSS. Fluoroscopy was turned on to allow visualization of five swallows at 0:00, 0:30, 1:30 and 2:30 (minutes:seconds [min:s]). We evaluated swallows for components of swallow physiology (oral bolus hold, initiation of pharyngeal swallow, timing of swallow initiation) and airway protection (penetration, aspiration). We used model-based linear contrasts to test differences in the percentage of swallows with low function component attributes.
Results: All components of swallow physiology exhibited a change throughout the VFSS (P≤0.0005). Changes were characterized by an increase in the number of sucks per swallow (P<0.0001), percentage of swallows with incomplete bolus hold (P=0.0005), delayed initiation of pharyngeal swallow (P<0.0001), delayed timing of swallow initiation (P=0.0004) and bolus airway entry (P<0.0001). These findings demonstrate that infants with dysphagia exhibit a change in swallow physiology throughout the videofluoroscopic swallow exam.
Conclusion: Fluoroscopic visualization that is confined to the initial swallows of the bottle feed limit the exam's diagnostic validity. Developing evidence-based procedural guidelines for infant VFSS execution is crucial for maximizing the exam's diagnostic and treatment yield.
Keywords: Dysphagia; Infants; Standardization; Swallowing; Videofluoroscopic swallow studies.