Effect of dialysis dose and membrane flux in maintenance hemodialysis.
BACKGROUND
The effects of the dose of dialysis and the level of flux of the dialyzer membrane on mortality and morbidity among patients undergoing maintenance hemodialysis are uncertain.


METHODS
We undertook a randomized clinical trial in 1846 patients undergoing thrice-weekly dialysis, using a two-by-two factorial design to assign patients randomly to a standard or high dose of dialysis and to a low-flux or high-flux dialyzer.


RESULTS
In the standard-dose group, the mean (+/-SD) urea-reduction ratio was 66.3+/-2.5 percent, the single-pool Kt/V was 1.32+/-0.09, and the equilibrated Kt/V was 1.16+/-0.08; in the high-dose group, the values were 75.2+/-2.5 percent, 1.71+/-0.11, and 1.53+/-0.09, respectively. Flux, estimated on the basis of beta2-microglobulin clearance, was 3+/-7 ml per minute in the low-flux group and 34+/-11 ml per minute in the high-flux group. The primary outcome, death from any cause, was not significantly influenced by the dose or flux assignment: the relative risk of death in the high-dose group as compared with the standard-dose group was 0.96 (95 percent confidence interval, 0.84 to 1.10; P=0.53), and the relative risk of death in the high-flux group as compared with the low-flux group was 0.92 (95 percent confidence interval, 0.81 to 1.05; P=0.23). The main secondary outcomes (first hospitalization for cardiac causes or death from any cause, first hospitalization for infection or death from any cause, first 15 percent decrease in the serum albumin level or death from any cause, and all hospitalizations not related to vascular access) also did not differ significantly between either the dose groups or the flux groups. Possible benefits of the dose or flux interventions were suggested in two of seven prespecified subgroups of patients.


CONCLUSIONS
Patients undergoing hemodialysis thrice weekly appear to have no major benefit from a higher dialysis dose than that recommended by current U.S. guidelines or from the use of a high-flux membrane.
Eknoyan
Garabed
G
Baylor College of Medicine, Houston, USA.
Beck
Gerald J
GJ
Cheung
Alfred K
AK
Daugirdas
John T
JT
Greene
Tom
T
Kusek
John W
JW
Allon
Michael
M
Bailey
James
J
Delmez
James A
JA
Depner
Thomas A
TA
Dwyer
Johanna T
JT
Levey
Andrew S
AS
Levin
Nathan W
NW
Milford
Edgar
E
Ornt
Daniel B
DB
Rocco
Michael V
MV
Schulman
Gerald
G
Schwab
Steve J
SJ
Teehan
Brendan P
BP
Toto
Robert
R
D000328:Adult; D000368:Aged; D005260:Female; D015312:Hemodialysis Solutions / Q000008:administration & dosage*; D006760:Hospitalization; D006801:Humans; D007676:Kidney Failure, Chronic / Q000378:metabolism / Q000401:mortality* / Q000628:therapy*; D008297:Male; D008567:Membranes, Artificial; D008875:Middle Aged; D016016:Proportional Hazards Models; D006435:Renal Dialysis / Q000295:instrumentation* / Q000379:methods; D016019:Survival Analysis; D014508:Urea / Q000378:metabolism
D015312:Hemodialysis Solutions; D008567:Membranes, Artificial; D014508:Urea