Effects of carbonation of liquids on penetration–aspiration and residue management

Objective Carbonation as a sensory enhancement strategy for prevention of aspiration of thin liquids has not been thoroughly studied. The aim of our study was to examine the effect of carbonation on penetration–aspiration and pharyngeal residue in dysphagia patients using Fiber-Optic Endoscopic Evaluation of Swallowing (FEES) and to identify parameters associated with a response to carbonation. Methods A cross-sectional study of patients undergoing FEES in a dysphagia clinic. Patients were offered 100 cc of dyed water. Penetration–aspiration was scored using the penetration–aspiration scale (PAS). Residue was scored using the Yale Pharyngeal Residue Severity Rating Scale (YPR-SRS). Patients with a PAS ≥ 2 for water were subsequently offered 100 cc of carbonated water. PAS, YPR-SRS and residue clearance were compared between thin and carbonated liquids. Multivariate logistic regression analysis was used to identify predictors for good response to carbonation. Results 84 patients were enrolled, 77.4% males, with diverse dysphagia etiologies (58.3% neurogenic, 11.9% radiation-induced, 23.8% deconditioning-induced, and 6% neck surgery induced). Median PAS was 7 (IQR 4–8) for thin liquids and 4.5 (IQR 2–8) for carbonated liquids (P = 0.0001). YPR-SRS was reduced for carbonated compared to thin liquids in the vallecula (1.58 ± 0.83 vs 1.76 ± 0.93, P = 0.001) and piriform sinuses (1.5 ± 0.87 vs 1.67 ± 0.9, P = 0.002). 31 patients had improvement in PAS with carbonation. Deconditioning as a dysphagia etiology was found to predict good response to carbonation on multivariate logistic regression analysis. Conclusion Carbonation may prevent aspiration and improve residue management for some patients with dysphagia for liquids. Level of evidence IV.