New Indicators for Optimal Dialysis Based on Creatinine Kinetics

Abstract

Background; Creatinine (Cr) is supposed to be uniformly distributed in body fluid, as is the case with urea nitrogen (UN). We calculated the normalized dialyser serum Cr (S-Cr) clearnce (Kt/Vcr), time averaged concentration of S-Cr (TACcr), and creatinine generation rate per body weight (gCr) on the basis of creatinine kinetics instead of urea k inetics and assessed whether these parameters would provide useful new indicators for optimal dialysis. Methods; Blood UN (BUN) and S-Cr values were measured in 13 hemodialysis patients immediately before and after a session of dialysis and immediately before the next session. Based on these measurements, the new indicators were calculated and compared with the conventional indicators [normalized dialyser urea clearnce (Kt/Vurea), time averaged concentration of BUN (TACBUN), protein catabolic rate (per) ]. Results; There was a significant positive correlation (r = 0.95, P<0.001) between Kt/Vcr (1.05 ± 0.15) and Kt/Vurea, and between TACcr (9.9 < 1.6) and TACBUN (r = 0.85, P <0.001). The gCr (27.9 < 5.5mg/kg/day) also correlated with per. Conclusion; Kt/Vcr and TACcr can be new indicators for optimal dialysis. The gCr may serve as a comprehensive indicator of nutritional conditions in hemodialysis patients.