Pharyngeal Residues Following Swallowing of Pureed Diets Thickened with a Gelling Agent or a Xanthan Gum-Based Thickener in Elderly Patients with Dysphagia

The ideal texture of pureed diets to prevent aspiration pneumonia remains unclear. The aim of this study was to evaluate the effectiveness of a pureed diet with either a gelling agent or a xanthan gum-based thickener to prevent pharyngeal residues in patients with dysphagia. We retrospectively analyzed a randomized, crossover trial of pureed rice with either a gelling agent or a xanthan gum-based thickener in patients with dysphagia. The enrolled patients were classified into mild and moderate-to-severe dysphagia groups. The primary outcome measure was degree of need for cyclic ingestion using test jelly for pharyngeal residuals (cyclic ingestion score). The secondary outcome was the patient's sense of material remaining in the throat following swallowing. Sixty-two patients (58% men; mean age 83 ± 9 years) with dysphagia were included. They were classified into mild dysphagia (n = 26) and moderate-to-severe dysphagia (n = 36) groups. In the moderate-to-severe dysphagia group, pharyngeal residuals were significantly less likely with pureed diets using a gelling agent than with those using a xanthan gum-based thickener, with respective median cyclic ingestion scores (range) of 1 (0-4) vs. 2.5 (0-4) (p = 0.001). There was no significant difference in pharyngeal residuals between the pureed diets in the mild dysphagia group. The multivariate analysis identified gelling agent as an important factor significantly associated with less pharyngeal residual after swallowing of pureed diet in patients with moderate-to-severe dysphagia. Pureed diets thickened by a gelling agent decrease pharyngeal residues in patients with moderate-to-severe dysphagia and may reduce risk of aspiration pneumonia.