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.