Dialysate flow rate and delivered Kt/Vurea for dialyzers with enhanced dialysate flow distribution.
نویسندگان
چکیده
BACKGROUND AND OBJECTIVES Previous in vitro and clinical studies showed that the urea mass transfer-area coefficient (K(o)A) increased with increasing dialysate flow rate. This observation led to increased dialysate flow rates in an attempt to maximize the delivered dose of dialysis (Kt/V(urea)). Recently, we showed that urea K(o)A was independent of dialysate flow rate in the range 500 to 800 ml/min for dialyzers incorporating features to enhance dialysate flow distribution, suggesting that increasing the dialysate flow rate with such dialyzers would not significantly increase delivered Kt/V(urea). DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We performed a multi-center randomized clinical trial to compare delivered Kt/V(urea) at dialysate flow rates of 600 and 800 ml/min in 42 patients. All other aspects of the dialysis prescription, including treatment time, blood flow rate, and dialyzer, were kept constant for a given patient. Delivered single-pool and equilibrated Kt/V(urea) were calculated from pre- and postdialysis plasma urea concentrations, and ionic Kt/V was determined from serial measurements of ionic dialysance made throughout each treatment. RESULTS Delivered Kt/V(urea) differed between centers; however, the difference in Kt/V(urea) between dialysate flow rates of 800 and 600 ml/min was NS by any measure (95% confidence intervals of -0.064 to 0.024 for single-pool Kt/V(urea), -0.051 to 0.023 for equilibrated Kt/V(urea), and -0.029 to 0.099 for ionic Kt/V). CONCLUSIONS These data suggest that increasing the dialysate flow rate beyond 600 ml/min for these dialyzers offers no benefit in terms of delivered Kt/V(urea).
منابع مشابه
The patient as a limit to dialysis technology.
Ward et al. show in this issue of CJASN that Kt/V urea does not improve by increasing the dialysate flow rate in dialyzers in which dialysate flow distribution has been optimized by changes in design (1). Such improved dialyzer designs were developed during the last decade, based on the awareness that poor dialysate flow distribution and the occurrence of preferential dialysate flow paths negat...
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ورودعنوان ژورنال:
- Clinical journal of the American Society of Nephrology : CJASN
دوره 6 9 شماره
صفحات -
تاریخ انتشار 2011