Interaction between Intradialytic Exercise and Hemodialysis Adequacy

Abstract

Background/Aims: According to mathematical modeling, intradialytic exercise of sufficient intensity and duration implemented in the second half of dialysis should be as efficacious as increasing dialysis time for dialysis adequacy. This assumption has not been tested in vivo. Methods: In this controlled trial, 11 hemodialysis (HD) patients (mean (SD) age 56 (13) years) were recruited. Each patient completed three trial arms in a randomized order: routine care (CONT), increased HD time of 30 min (TIME), and intradialytic exercise (EXER), 60 min of cycling at 90% of the lactate threshold in the last 90 min of HD. The primary outcome was eKt/V_urea. Secondary outcomes included reduction and rebound ratios of urea, creatinine, phosphate and β₂-microglobulin.Outcomes were calculated from blood sampling collected pre-, post- and 30 min post-HD and confirmed with dialysate sampling. Results: Exercise was not as efficacious as increased HD time for eKt/V_urea (EXER vs. CONT, mean change (95% CI): 0.03 (-0.05 to 0.12); TIME vs. CONT: 0.15 (0.05-0.26)). Exercise was less efficacious at improving reduction ratios of urea and creatinine. However, exercise was more efficacious than increased dialysis time for phosphate reduction ratio (EXER vs. CONT: 8.6% (0.5-16.7); TIME vs. CONT: 5.0% (-1.0 to 11.1)). Conclusion: This study utilized a rigorously controlled in vivo design to test mathematical models and assumptions regarding dialysis adequacy. Intradialytic exercise towards the end of HD cannot replace the prescription of increased HD time for dialysis adequacy, but may be an adjunctive therapy for serum phosphate control.

Impact of intradialytic exercise intensity on urea clearance in hemodialysis patients

“…The impact of IDE on Kt/V is inconsistent in the literature, with both positive (Kong et al 1999;Parsons et al 2006) and no changes reported (Afshar et al 2010;Kirkman et al 2013). Compared with the control session, Kt/V was found to be slightly, but significantly greater during the 55% protocol, but not during the 70% protocol.…”

The effects of intradialytic exercise on hemodialysis adequacy: A systematic review

“…Seven of the 13 studies that reported spKt/V urea showed no statistical significance and small effect sizes for intradialytic exercise . Six of the 13 studies that reported spKt/V urea favored intradialytic exercise showing statistical significance and/or a large effect size.…”

“…Four studies allowed exercise into the third hour of dialysis . One study specifically prescribed exercise in the last half of dialysis …”

“…No serious or unexpected adverse events relating to exercise were reported. Expected adverse events that were reported in a relatively small number of cases included episodic hypotension and intradialytic cramping …”

Intradialytic exercise with blood flow restriction: Something to add to hemodialysis adequacy? Findings from a crossover study

“…[5][6][7][8][9][10][11][12]18 Intradialytic exercise increases solutes removal by increasing cardiac output, which, combined with higher metabolic need for the exercising muscle, leads to muscle vasodilation. [5][6][7][8][9][10][11][12]18 Intradialytic exercise increases solutes removal by increasing cardiac output, which, combined with higher metabolic need for the exercising muscle, leads to muscle vasodilation.…”