EFFECT ON THE DIALYSIS DOSE OF THE EXERCISE WITH VIRTUAL REALITY DURING THE FIRST VERSUS SECOND PART OF THE DIALYSIS SESSION

Abstract Background and Aims Exercise using non-immersive virtual reality (VR) is a novel rehabilitation method for patients undergoing hemodialysis treatment. This method has shown in a pilot study improved physical function and health-related quality of life. There is controversy about the effect of intradialysis exercise on the dialysis dose. Furthermore, theoretical models also indicate that intradialytic exercise at the end of session may be beneficial in postdialysis rebound. Objective: to determine effect of exercise with virtual reality during the first two hours and the last two hours of dialysis session on postdialysis rebound and dialysis dose. Method The design was a randomized clinical trial. Patients were randomized to exercise in the first (Start group) or last two hours (End group) of dialysis session. Dialysis dose was measured through the monocompartimental Kt/V, and the potassium, urea, phosphorus and creatinine rebound was calculated after both baseline and exercise sessions at 17 weeks. Intradialysis exercise consisted of a video game adapted to dialysis: Treasure hunting. It is a non-immersive VR game in which the patient must catch some objectives avoiding obstacles by moving the lower limbs. The exercise session lasted from 20 to 40 minutes. Intensity was checked through the rate of perceived exertion. An mixed ANOVA of repeated measures was used to assess the effect of the intervention. Patients exercised for 17 weeks. Results 43 patients participated, 11 dropouts, 17 in Start group and 15 in End group. Mean age 73 years, males 28. There were no significant differences in rebound urea, creatinine, potassium and phosphorus 30 minutes after finishing dialysis. The mean baseline Kt/V was 1.65 (SD 0.21) and with exercise 1.75 (SD 0.25). The mixed ANOVA analysis showed a significant time effect with an increase in Kt/V (mean 0.10, 95% CI 0.02-0.19, p 0.018) from exercise session vs baseline. No group per time significant interaction was found, so that there was no difference in the dialysis dose between Start and End group. Conclusion Intra-dialysis exercise with virtual reality can improve the dose of dialysis, no matter the timing of the exercise is performed.