Conventional hemodialysis (HD) is associated with dialysis-induced hypotension (DIH) and ineffective phosphate removal, say Brazilian nephrologists at the University São Paulo. Their approach to try and reduce DIH and increase phosphate removal focused on the legs – the authors hypothesized that cycling and pneumatic compression would provide higher venous return, preserve central blood flow and offer more phosphate to the dialyzer. The results proved them half-correct: While pneumatic compression during the first hour of dialysis was indeed associated with less DIH, there was no effect on fluid parameters, and neither exercise nor pneumatic compression increased phosphate removal.
The study included 21 patients. Each patient underwent 3 different forms of HD: controls (normal HD); cycling exercise during the first 60 min; and pneumatic compression during the first 60 min. DIH was defined as a drop in mean arterial pressure (MAP) ≥ 20 mm Hg.
All three groups (control, cycling, pneumatic compression) had similar results regarding ultrafiltration rate, delta weight, delta of total and intra and extracellular body water. Delta MAP was less changed by pneumatic compression vs. control and cycling groups. DIH occurred most often in controls (43 %), followed by the cycling and compression groups (38 and 24 %, respectively). None of the interventions increased phosphate removal. Higher phosphate removal was dependent on ultrafiltration, pre dialysis serum phosphate, and higher parathyroid hormone.
Pneumatic compression during the first hour of dialysis was associated with less DIH, but there was no effect on fluid parameters. None of the two interventions increased phosphate removal.