Evaluation of the Effect of Xylitol Gum on Thirst, Dry Mouth and Nausea in Patients Undergoing Haemodialysis

Haemodialysis is the most preferred method in the treatment of kidney failure in the world and in Turkey. According to the 2019 reports of the United States renal data system, haemodialysis is applied to 86.9% of the chronic kidney patients. In Turkey, this rate was 74.8% as of the end of 2018, according to the data reports of the Turkish Society of Nephrology. Patients undergoing haemodialysis have to cope with the adverse effects of the chronic disease as well as complications that develop due to treatment. Causes such as drugs used in haemodialysis treatment, fluid restriction, high ultrafiltration, weight gain between two haemodialysis sessions, dialysis imbalance syndrome and deterioration of oral pH, cause fluid-electrolyte imbalances, hypotension, pain, muscle cramps, thirst, dry mouth and leads of bothersome symptoms such as nausea. These may increase morbidity and mortality by causing premature termination of haemodialysis treatment or dialysis failure. Patients undergoing haemodialysis should be able to alleviate thirst, dry mouth and nausea with a method that does not disrupt fluid restriction. The combination of the salivary gland stimulant effect of the refreshing xylitol alone together with the mechanical effect of chewing gum has the effect of reducing thirst and dry mouth. Effective in reducing thirst, dry mouth and nausea in patients undergoing haemodialysis and a method that nurses can choose independently, xylitol gum can be easily used as a safe method and increases intraoral pH, prevents oral mucositis, facilitates periodontal healing and contributes to an effective treatment process. Thirst, dry mouth and nausea are quite common bothersome symptoms in patients undergoing haemodialysis. Thirst is a symptom associated with the desire to drink water due to insufficient body fluids and is one of the body's defence mechanisms. The inability of the saliva secreted to maintain the moistness of the oral mucosa is defined as "thirst". Thirst is controlled centrally and perceived peripherally as the feeling of dry mouth. According to Bots et al., 47.8% of patients on haemodialysis were thirsty during the day, 41.6% felt thirsty before dialysis, 24.7% during dialysis and 29.9% after dialysis. Dry mouth is a symptom that results from excessive reduction in the amount of saliva or problems with secretion, usually due to under-functioning of the salivary glands. When the amount of saliva decreases below 0.1 mL/min when evaluated together with clinical symptoms, it is defined as "dry mouth (xerostomia)". Bots et al. determined that 76.4% of the patients on haemodialysis treatment experienced dry mouth, while this figure was 56.2% according to Akgöz and Arslan. Thirst and dry mouth in patients on haemodialysis causes several clinical symptoms such as the sensations of sticky or burning tongue, need to drink liquid, difficulty swallowing solid food, stomatitis, increased dental caries, dysarthria and night sleep interruptions. Nausea is the conscious recognition of the excitation of a part of the vomiting centre or a closely related area and subjective feeling of the need to vomit. Increased urea concentration in the saliva of the patients and worsening of oral pH and exposure of the oral cavity to pathogens increase the risk of developing infection, disrupt the integrity of the mucous membrane and intensify the feeling of nausea Of the patients on haemodialysis treatment, 21-54% according to Almutary and 41% according to Akgöz and Arslan experienced nausea. Uncontrollable nausea can cause undesirable symptoms such as fluid-electrolyte imbalance, dehydration, vomiting, anorexia and weight loss, and also reduce the absorption and excretion of drugs used in the treatment. Based on the previous studies in the literature, xylitol gum, used generally as an auxiliary product in providing oral hygiene and preventing dental plaques and caries, has proven effects such as increasing saliva pH, protecting salivary proteins, reducing mouth and nasopharyngeal infections and protecting mucous membrane integrity. With its refreshing and pleasant taste, xylitol gum is also recommended as a natural, economical, easily accessible and safe product for reducing thirst, dry mouth and nausea in patients undergoing haemodialysis. However, studies evaluating the effect of xylitol gum on thirst and dry mouth in patients undergoing haemodialysis are limited in both the national and international literature. In addition, studies conducted with different sample groups and different methods (patients who underwent laparoscopic breast surgery, colonoscopy preparation, gynaecological operations) concluded that chewing gum reduces nausea but no study evaluating the effect of xylitol gum on nausea in patients undergoing haemodialysis could be found.