Will mouth wash solutions of water, salt, sodiumbicarbonate or citric acid improve upper gastrointestinal symptoms in chronic kidney disease.

BACKGROUND: Uraemic symptoms including taste changes, nausea and dry retching are common in chronic kidney disease (CKD). Taste buds detect five basic tastes: sweet, salty, sour, umami and bitter. Saliva in CKD usually has increased concentrations of urea, sodium, potassium, phosphate and higher pH levels. Genetic sensitivities to the bitter taste, with the changes in saliva can cause taste changes and impact uraemic symptoms. AIM: The aim of this study was to assess if mouth wash solutions of water, salt, sodium bicarbonate or citric acid improves upper gastrointestinal (GI) symptoms in CKD patients. METHODS: An interventional crossover study with 42 CKD patients (21 men, 21 women) complaining of upper GI symptoms were recruited. Subjects completed a questionnaire to assess symptoms and tested for genetic taste sensitivities. Saliva samples were analysed. Mouth rinse solutions of salt, bicarbonate, citric acid and de-ionised water were trialled in randomized order for patient reaction and symptom improvement. RESULTS: All 42 patients experienced anorexia, 39 (93%) reported taste changes, 27 (48%) nausea and 27 (48%) dry retching. All solutions improved symptoms in some patients. Sodium bicarbonate (P = 0.005) gave the greatest improvement in mouth feel and symptom control compared with the least favoured citric acid solution. Sixty-six percent of patients found sodium bicarbonate beneficial with 40% preference over other solutions. CONCLUSION: Simple mouthwashes can be used to relieve or eliminate some uraemic symptoms. Rinsing the mouth with a sodium bicarbonate solution cleanses receptors on taste buds and may alter mouth pH thereby reducing some upper GI symptoms that CKD patients can experience.

Saliva composition and upper gastrointestinal symptoms in chronic kidney disease.

OBJECTIVE: To investigate self-reported upper gastric symptoms experienced by patients with chronic kidney disease (CKD) and compare associations between uraemic symptoms and saliva composition. METHODS: In a cross-sectional observational study, 30 patients with Stages 4 and 5 CKD were selected from a tertiary hospital renal outpatient clinic. Subjects answered a questionnaire to assess upper gastrointestinal (GI) symptoms. A saliva sample was collected to determine biochemical composition. Possible associations between saliva composition and uraemic upper GI symptoms were assessed. RESULTS: Only 3 (10%) patients reported no upper GI symptoms whilst 19 (63%) complained of a dry mouth, 16 (56%) had a change in taste, 9 (30%) had nausea, 7 (23%) vomited and 7 (23%) dry retched. Lower saliva bicarbonate concentration related to both dry mouth (p < 0.003) and dry retching (p < 0.01). An elevated level of saliva calcium was also implicated in a dry mouth sensation (p < 0.01). Nausea was associated with higher saliva sodium levels (p < 0.03) and a higher saliva sodium/potassium ratio (p < 0.02). CONCLUSION: Altered saliva composition in patients with Stages 4 and 5 CKD may be associated with uraemic upper GI symptoms. In particular, lower saliva concentrations of bicarbonate are associated with dry mouth and retching. Higher saliva calcium levels are also related to a dry mouth whilst higher saliva sodium levels and a greater sodium/potassium ratio are associated with nausea. Further studies investigating strategies to improve uraemic symptoms via changes in saliva are required.