Defining peritoneal dialysis adequacy: Kt/Vurea revisited.
BACKGROUND
Although adequate peritoneal dialysis is not well defined, Kt/Vurea has been used as an index, and various values have been proposed. However, conflicting evidence existed regarding the appropriateness of using Kt/Vurea to define dialysis adequacy and its optimal value. Therefore, the present study performed a theoretical analysis on whether we should use Kt/Vurea to define peritoneal dialysis adequacy and what the optimal value should be.


METHODS
The three-pore model was applied to evaluate the transport patterns of different molecular weight solutes and fluid. Optimal Kt/Vurea value was estimated based on urea kinetics and nitrogen balance.


RESULTS
The removal pattern of small solute, middle and large molecules, and fluid and sodium are quite different. Depending on the dwell time, higher urea removal does not necessarily mean higher sodium, fluid, and other molecular weight solute removals. To reach nitrogen balance, the dialysis doses and therefore Kt/Vurea values varied with different dietary protein intakes in a patient with a given weight and residual renal function.


CONCLUSIONS
This study shows that Kt/Vurea in peritoneal dialysis cannot represent the removal of other solutes and fluid, indicating that Kt/Vurea alone should not be used as a sole indicator of peritoneal dialysis adequacy. The results also show that optimal Kt/Vurea cannot be a fixed value, but varies according to individual dietary protein intake and tolerable blood urea level.
Zhe
Xing-Wei
XW
Division of Nephrology, Third Hospital, Peking University, Beijing, China.
Shan
Yi-Sheng
YS
Cheng
Lei
L
Tian
Xin-Kui
XK
Wang
Tao
T
D001692:Biological Transport; D015415:Biomarkers / Q000097:blood; D001806:Blood Urea Nitrogen; D015314:Dialysis Solutions / Q000378:metabolism*; D004044:Dietary Proteins / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005947:Glucose / Q000378:metabolism* / Q000494:pharmacology; D017583:Hemodiafiltration; D006801:Humans; D007700:Kinetics; D008432:Mathematical Computing; D010531:Peritoneal Dialysis, Continuous Ambulatory; D012964:Sodium / Q000378:metabolism; D013997:Time Factors; D016896:Treatment Outcome; D014508:Urea / Q000378:metabolism*; D014511:Uremia / Q000378:metabolism / Q000628:therapy
D015415:Biomarkers; D015314:Dialysis Solutions; D004044:Dietary Proteins; D014508:Urea; D012964:Sodium; D005947:Glucose