Survey on the Effect of Transmembrane Pressure on MiddleMolecules’ Excretion in Bicarbonate Base Hemodialysis

Background and aims: the transmembrane pressure (tmp) is an important factor in removing the moleculesduring hemodialysis. in this study we explained the effect of ultrafiltration increase on the clearance of middlemolecules in the hemodialysis patients of kashan.methods: this clinical trial is a before-after study that was performed on 40 hemodialyzed individuals in 2008.at the first stage, the participants were dialyzed with ultrafiltration equal to the difference of their present weightand their dry weight and in the 2nd stage the ultrafiltration was increased 2 liters and clearance of each solutewas mesured in both stages.rusults: in the first stage, the amount of reduction in predialysis serum beta 2 microglobulin (beta2m) levelwas 3.5% (p = 0.05) and in the second stage it was 14.4% (p = 0.001). excretion of the small molecules (bun,cr and p) in the second stage of hemodialysis in comparision with the first stage of dialysis (conventionalmethod) revealed no meaningful change.in the all previous studies, low flux dialysis membrane had been used in a standard way, and these studiesdidn’t pay attention to ultrafiltration increase but in this research we improved the role of convection inexcretion of the middle molecules by ultrafiltration increase through adding tmp. all pores of the low fluxmembranes are not uniform and unisize. this manufacturing was problem associated with rising hydrostaticpressure through increase tmp help us for removing beta2m with convection.conclusions: the results showed that we can increase the amount of excretion of the middle molecules anddialysis capability with increasing the tmp during bicarbonate base hemodialysis through low flux membranes.