Evaluating a new method to judge dialysis treatment using online measurements of ionic clearance

Abstract

New technology now supports direct online measurements of total dialysis dose per treatment, Kt. An outcome-based, nonlinear method for estimating target Kt in terms of ionic clearance measurements and body surface area (BSA) has been described recently. This is a validation study of the new method that evaluates the relationship between the (actual Kt-target Kt) difference and death risk. Patients with Kt measurements during March 2004 were identified (N=59,644). Target Kt was determined for each patient using the new method. Patients were then grouped by (actual Kt-target Kt) decile. They were also grouped by (actual URR-target URR) decile. Cox analysis-based risk profiles were constructed using those groupings. The (actual Kt-target Kt) difference profiles suggested improving death risk as Kt increased from below target to equal target. Risk ratios then flattened and remained so until (actual Kt-target Kt) reached the highest decile at which it appeared to improve, suggesting a possible biphasic profile. The (URR-target URR) risk profile was U-shaped. Death risk was related to the difference between the actual Kt and a target Kt value selected using the new nonlinear method. The method is therefore valid for prescribing and monitoring hemodialysis treatment.

Citrate versus Acetate-Based Dialysate in On-Line Haemodiafiltration. A Prospective Cross-Over Study

“…Kt/V has been widely documented as a valid parameter for the measurement and monitoring of dialysis dose [20,21,22,23]. The results of this study show that Kt/V can be increased by 2.6% in high-efficiency OL-HDF patients treated with citrate dialysis fluid, improving dialysis dose administrated with no changes in the pattern of dialysis, or differences in blood flow or session time.…”

Illustrating Use of a Clinical Data System

“…Curves like Figure 6, or tables of Kt by BSA, are easily used to find a target Kt for any patient (36). The method has been validated using a different patient sample (38).…”

“…It is not appropriate for deciding patient survival. Ionic methods now measure K directly; Kt is also measured (18,35,36,38). Relationships among Kt, body surface area (BSA), and risk can now be tested using independent measures evaluating any interaction between Kt and BSA.…”

Access Survival amongst Hemodialysis Patients Referred for Preventive Angiography and Percutaneous Transluminal Angioplasty

“…The clinical information system collected parameters on vascular access type (arteriovenous fistula or graft, venous catheter), location (wrist, forearm, upper arm), side (left, right), date of first use, and date of access failure. Dialysis clearance and intra-access blood flow rate (IAF) were measured using the method of ionic online clearance (13). At the time of the study, the FMCNA access monitoring program consisted of monthly IAF screening.…”