Purpose. Dialysis systems that are able to prepare the reinfusion fluid online have recently been introduced in clinical practice. These systems should increase the efficiency and lower both the contamination risks and costs of convective therapies. Data about dialysis dose in hemofiltration (HF) are scarce; in particular, the quantity of reinfusion fluid is still a matter of debate. Methods. We carried out a prospective study on 4 uremic male patients (age, 66-72 years; dialysis duration, 45-149 months; BMI 21-23 kg/m(2)), who had been scheduled to undergo predilution HF with online-prepared bicarbonate reinfusion fluid for 225 (plus or minus) 21 minutes, 3 times/week. The study consisted of 4 phases lasting 5 weeks each, during which dialysis time was kept constant. Blood flow rate was set at 300 ml/min in phases I and II, and at 400 ml/min in phases III and IV. Reinfusion volume was prescribed based on total body water (TBW) calculated by Watson's formula. Reinfusion volume was equal to TBW in phases I and III, and corresponded to 1.5 times TBW in phases II and IV. Dialysis efficiency was estimated by different formulae for Kt/V calculation. Moreover, we calculated the reduction ratio for urea and (beta)2-microglobulin. Results. The highest Kt/V values were obtained in all patients when blood flow was 400 ml/min and the reinfusion volume was 1.5 times TBW. In this setting, a (beta)2-microglobulin reduction ratio of between 60% and 80% was measured. Conclusions. Our data suggest that small molecule removal by online predilution HF is adequate in patients with a low BMI and a vascular access that allows a high blood flow rate.
Determining the prescription for online predilution hemofiltration: Our experience and a review of the literature
FABBIAN, Fabio
2002
Abstract
Purpose. Dialysis systems that are able to prepare the reinfusion fluid online have recently been introduced in clinical practice. These systems should increase the efficiency and lower both the contamination risks and costs of convective therapies. Data about dialysis dose in hemofiltration (HF) are scarce; in particular, the quantity of reinfusion fluid is still a matter of debate. Methods. We carried out a prospective study on 4 uremic male patients (age, 66-72 years; dialysis duration, 45-149 months; BMI 21-23 kg/m(2)), who had been scheduled to undergo predilution HF with online-prepared bicarbonate reinfusion fluid for 225 (plus or minus) 21 minutes, 3 times/week. The study consisted of 4 phases lasting 5 weeks each, during which dialysis time was kept constant. Blood flow rate was set at 300 ml/min in phases I and II, and at 400 ml/min in phases III and IV. Reinfusion volume was prescribed based on total body water (TBW) calculated by Watson's formula. Reinfusion volume was equal to TBW in phases I and III, and corresponded to 1.5 times TBW in phases II and IV. Dialysis efficiency was estimated by different formulae for Kt/V calculation. Moreover, we calculated the reduction ratio for urea and (beta)2-microglobulin. Results. The highest Kt/V values were obtained in all patients when blood flow was 400 ml/min and the reinfusion volume was 1.5 times TBW. In this setting, a (beta)2-microglobulin reduction ratio of between 60% and 80% was measured. Conclusions. Our data suggest that small molecule removal by online predilution HF is adequate in patients with a low BMI and a vascular access that allows a high blood flow rate.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
