10432415

pubmed:Citation

2

The normalized treatment ratio [Kt/V = the ratio of the urea clearance x time product to total body water] and the urea reduction ratio (URR) have become widely accepted measures of dialysis dose. Both are related to and derived from pharmacokinetic models of blood urea concentration during the dialysis cycle. Theoretical reconsideration of the models revealed that the premise about V on which they rest (that is, that V is a passive diluent with no survival-associated properties of its own) is flawed if the intended use of the models is for profiling clinical outcome (for example, mortality) rather than estimating urea concentration. As a proxy for body mass, V has survival-associated properties of its own. Thus, indexing clearance x time to body size could create an offsetting combination whereby one measure favorably associated with survival (Kt) is divided by another (for example, V). Observed clinical paradoxes support that interpretation. For example, patients with a low body mass have both higher URR and higher mortality than heavier patients. Increasing mortality is often observed at high URR, suggesting the possibility of "over-dialysis." Black patients tend to be treated at lower URR than whites but enjoy better survival on dialysis. Therefore, clearance x time was evaluated as an outcome-based measure of dialysis dose, not indexed to V, and various body size estimates were evaluated as separate and distinct measures.

eng

IM

MEDLINE

0085-2538

Print

NLM

729-37

pubmed-meshheading:10432415-Adult, pubmed-meshheading:10432415-African Continental Ancestry Group, pubmed-meshheading:10432415-Aged, pubmed-meshheading:10432415-Body Mass Index, pubmed-meshheading:10432415-Creatinine, pubmed-meshheading:10432415-Dialysis Solutions, pubmed-meshheading:10432415-European Continental Ancestry Group, pubmed-meshheading:10432415-Female, pubmed-meshheading:10432415-Humans, pubmed-meshheading:10432415-Kidney Failure, Chronic, pubmed-meshheading:10432415-Logistic Models, pubmed-meshheading:10432415-Male, pubmed-meshheading:10432415-Middle Aged, pubmed-meshheading:10432415-Models, Biological, pubmed-meshheading:10432415-Renal Dialysis, pubmed-meshheading:10432415-Risk Assessment, pubmed-meshheading:10432415-Sex Factors, pubmed-meshheading:10432415-Treatment Outcome, pubmed-meshheading:10432415-Urea

The urea [clearance x dialysis time] product (Kt) as an outcome-based measure of hemodialysis dose.

Journal Article