The effect of bolus consistency on dysphagia in unilateral vocal cord paralysis

OBJECTIVE: To examine the risk of aspiration for liquid versus paste bolus consistencies in patients with unilateral vocal cord paralysis (UVCP). METHODS: The swallowing function of adult patients with UVCP was prospectively studied videofluorographically to examine the incidence of laryngeal penetration and aspiration for both liquid and paste boluses. The degree of penetration or aspiration was quantified using the penetration-aspiration scale (PAS). The presence and location of pharyngeal bolus residue were also documented for each consistency. Results were compared between liquid and paste bolus consistencies. RESULTS: Fifty-five patients with UVCP were studied with a mean age of 60.2 years. Intrathoracic surgery or malignancy accounted for 38 (69.1%) of cases. The mean PAS scores for liquid and paste bolus consistency were 3.1 vs. 1.5, respectively (P < 0.001). The liquid bolus penetrated in 19 (34.5%) patients and was aspirated in 11 (20%) patients. In contrast, the paste bolus penetrated in 12 (21.8%) cases and was aspirated in 0 cases (P < 0.001). Pharyngeal residue was more likely to occur at the base of the tongue or vallecula for the paste bolus consistency versus the liquid bolus. CONCLUSIONS: A significant percentage of patients with UVCP will aspirate thin liquids. Paste bolus consistencies are safer for patients with UVCP as they are much less likely to lead to penetration or aspiration despite a higher prevalence of pharyngeal residue.