The Effect of Mechanically-Generated Vibrations on the Efficacy of Hemodialysis; Assessment of Patients' Safety: Preliminary Reports

Abstract

Muscle activity during a hemodialysis procedure improves its efficacy. We have formulated a hypothesis that vibrations generated by a specially-designed dialysis chair can, the same as physical exercise, affect the filtering of various fluids between fluid spaces during the hemodialysis procedure. This prospective and interventional study included 21 dialyzed patients. During a single dialysis session, each patient used a prototype device with the working name "vibrating chair". The chair's drive used a low-power cage induction motor, which, along with the worm gear motor, was a part of the low-frequency (3.14 Hz) vibration-generating assembly with an amplitude of 4 mm. Tests and measurements were performed before and after the vibration dialysis. After a single hemodialysis session including five 3-min cycles of vibrations, an increase in K t / V in relation to non-vibration K t / V ( 1.53 ± 0.26 vs. 1.62 ± 0.23 ) was seen. Urea reduction ratio increased significantly ( 0.73 ± 0.03 vs. 0.75 ± 0.03 ). A significant increase in systolic blood pressure was observed between the first and the third measurement ( 146 ± 18 vs. 156 ± 24 ). The use of a chair generating low-frequency vibrations increased dialysis adequacy; furthermore, it seems an acceptable and safe alternative to intradialytic exercise.

Keywords: Kt/V; hemodialysis; physical activity; urea reduction ratio (URR); vibrations.

Figure 1

Dialysis adequacy measures of (A) $Kt/V$ and (B) URR during non-vibration and vibration hemodialysis.

Figure 2

Systolic (A) and diastolic (B) blood pressure values in three consecutive measurements carried out during vibration hemodialysis. 1, baseline measurement before the first cycle of vibrations; 2, measurement after the second cycle of vibrations; 3, final measurement after the fifth cycle of vibrations.

Figure 2

Systolic (A) and diastolic (B) blood pressure values in three consecutive measurements carried out during vibration hemodialysis. 1, baseline measurement before the first cycle of vibrations; 2, measurement after the second cycle of vibrations; 3, final measurement after the fifth cycle of vibrations.