Hemodynamic and perceptual responses to blood flow-restricted exercise among patients undergoing dialysis

Abstract

End-stage kidney disease is associated with reduced exercise capacity, muscle atrophy, and impaired muscle function. While these may be improved with exercise, single modalities of exercise do not traditionally elicit improvements across all required physiological domains. Blood flow-restricted exercise may improve all of these physiological domains with low intensities traditionally considered insufficient for these adaptions. Investigation of this technique appeals, but is yet to be evaluated, in patients undergoing dialysis. With the use of a progressive crossover design, 10 satellite patients undergoing hemodialysis underwent three exercise conditions over 2 wk: two bouts (10 min) of unrestricted cycling during two consecutive hemodialysis sessions ( condition 1), two bouts of cycling with blood flow restriction while off hemodialysis on 2 separate days ( condition 2), and two bouts of cycling with blood flow restriction during two hemodialysis sessions ( condition 3). Outcomes included hemodynamic responses (heart rate and blood pressure) throughout all sessions, participant-perceived exertion and discomfort on a Borg scale, and evaluation of ultrafiltration rates and dialysis adequacy (Kt/V) obtained post hoc. Hemodynamic responses were consistent regardless of condition. Significant increases in heart rate, systolic blood pressure, and mean arterial blood pressure ( P < 0.05) were observed postexercise followed by a reduction in blood pressures during the 60-min recovery (12, 5, and 11 mmHg for systolic, diastolic, and mean arterial pressures, respectively). Blood pressures returned to predialysis ranges following the recovery period. Blood flow restriction did not affect ultrafiltration achieved or Kt/V. Hemodynamic safety and tolerability of blood flow restriction during aerobic exercise on hemodialysis is comparable to standard aerobic exercise.

The impact of intradialytic cycling on the removal of protein-bound uraemic toxins: A randomised cross-over study

“…Many contradictory results on the impact of intradialytic cycling on urea removal have been published over the last two decades. 11–18,20,25,31 In our study, no impact of cycling was found. Most studies showing an increased Kt/V urea were RCTs running over several weeks (8–20 weeks).…”

“…11–13 And this is also the case for the more recently performed studies which share the same conclusions as the present study. 18,20…”

“…Already in the late 90's, intradialytic exercise has been promoted to increase small solute based dialysis adequacy 11 . While different studies showed improved reduction ratios and/or solute removal for urea [12][13][14][15][16][17] , several more recently performed studies could however not confirm these findings [18][19][20] . A systematic review of the current literature thus described a lack of efficacy for intradialytic exercise to enhance urea clearance 21 .…”

“…11 While different studies showed improved reduction ratios and/or solute removal for urea, 12–17 several more recently performed studies could however not confirm these findings. 18–20 A systematic review of the current literature thus described a lack of efficacy for intradialytic exercise to enhance urea clearance. 21 However, urea is not representative for the kinetics of other small and water soluble toxins, such as phosphate.…”

Effects of Different Types of Exercise on Kidney Diseases

“…The researcher also reported that the mentioned cases were overloaded with fluids and ultrafiltration was prescribed for them. In this study, it was also suggested that the ratio should be considered as 1.4 to ensure dialysis adequacy [ 69 ]. In this regard, Cardoso et al examined the effect of intradialytic exercise with BFR and compared it with traditional exercise.…”