Videoradiographic analysis of how carbonated thin liquids and thickened liquids affect the physiology of swallowing in subjects with aspiration on thin liquids.

PURPOSE To analyze how carbonated thin liquids affected the physiology of swallowing in dysphagic patients. MATERIAL AND METHODS 40 patients were analyzed; 36 were neurologically impaired. During a therapeutic videoradiographic swallowing examination the patients had to swallow liquids with the following consistencies three times: thin, thickened and carbonated. The liquids were given in doses of 3 x 5 ml. The swallows were analyzed regarding penetration/aspiration, pharyngeal transit time and pharyngeal retention. RESULTS Significant difference was found regarding penetration/aspiration when comparisons were made between thin liquid and carbonated thin liquid (p<0.0001). Carbonated liquid reduced the penetration to the airways. The comparison between thin liquid and thickened liquid (p<0.0001) showed significant less penetration with thickened liquids. Pharyngeal transit time was reduced both when comparing thin liquid with thin carbonated liquid (p<0.0001) and thickened liquid (p<0.0001). Pharyngeal retention was significantly reduced (p<0.0001) with carbonated thin liquid compared to thickened liquid. The comparison of thin liquids and carbonated thin liquids showed p=0.0013, thin and thickened liquids p=0.0097. CONCLUSIONS Carbonated liquids reduced penetration/aspiration into the airways, reduced pharyngeal retention and pharyngeal transit time became shorter. Therefore, carbonated liquids are a valuable treatment option for patients with penetration/aspiration. Thickened liquids may still be an option for patients who cannot tolerate carbonated liquids and liquids with this consistency are safer than thin liquids.