Association of Kt/V and creatinine clearance with outcomes in anuric peritoneal dialysis patients.
BACKGROUND
The 2006 Kidney Disease Outcomes Quality Initiative recommended a minimum total Kt/V of 1.7, eliminated creatinine clearance (Ccr) as a target, and recommended the use of ideal body weight to calculate Kt/V. We assessed these recommendations as predictors of outcomes in anuric peritoneal dialysis patients.


METHODS
Retrospective observational study using administrative data.


METHODS
1,432 peritoneal dialysis patients with anuria from January 1, 1994, to January 31, 2005, in a national sample (1,428 with Kt/V, 1,416 with Ccr).


METHODS
Kt/V and Ccr at anuria; Kt/V based on actual body weight and ideal body weight.


METHODS
Association of dialysis adequacy with mortality and time to first hospitalization after anuria assessed by using accelerated failure time models.


RESULTS
293 anuric patients had Kt/V less than 1.7, 366 had Kt/V of 1.7 to 2.0, and 769 had Kt/V greater than 2.0, using actual body weight for calculation. In unadjusted analyses, Kt/V calculated using actual body weight both less than 1.7 (-41.3%; 95% confidence interval [CI], -55.5 to -22.6) and 1.7 to 2.0 (-26.1%; 95% CI, -42.6 to -4.6) were associated with shorter time to mortality. Kt/V calculated using actual body weight less than 1.7 was associated with shorter time to hospitalization (-38.1%; 95% CI, -50.0 to -23.4), but Kt/V calculated using actual body weight of 1.7 to 2.0 was not a significant predictor (-3.3%; 95% CI, -21.1 to 18.6). After adjustment, Kt/V calculated using actual body weight less than 1.7 remained associated with mortality (-25.3%; 95% CI, -41.1 to -4.8) and hospitalization (-33.4%; 95% CI, -47.1 to -16.0). Ccr did not predict mortality. In unadjusted analysis, Ccr was not associated with hospitalization, but after adjustment, Ccr less than 50 L/wk/1.73 m(2) was significantly associated with shorter time to hospitalization (-19.9%; 95% CI, -35.0 to -1.3). Kt/V using ideal body weight was not a significant predictor in adjusted models.


CONCLUSIONS
This study was nonrandomized, with few malnourished patients. In addition, there is a potential for informative censoring for transfer to hemodialysis therapy before anuria.


CONCLUSIONS
Kt/V calculated using actual body weight less than 1.7 in anuric peritoneal dialysis patients is associated with increased mortality and hospitalization. Use of ideal body weight to calculate Kt/V weakened the associations with outcomes and therefore cannot be recommended.
Fried
Linda
L
Renal Section, VA Pittsburgh Healthcare System, Pittsburgh, PA 15240, USA. linda.fried@va.gov
Hebah
Nasser
N
Finkelstein
Fredric
F
Piraino
Beth
B
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001002:Anuria / Q000378:metabolism / Q000401:mortality* / Q000628:therapy*; D001835:Body Weight; D003404:Creatinine / Q000378:metabolism*; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis; D012189:Retrospective Studies; D014508:Urea / Q000378:metabolism*; D055815:Young Adult
D014508:Urea; D003404:Creatinine