Comparison of alternative methods for scaling dialysis dose.

Area of Science:

• Nephrology
• Biomedical Engineering
• Clinical Research

Background:

• Hemodialysis (HD) adequacy is typically measured by Kt/Vurea, but normalizing factors like Vurea have been questioned.
• Alternative parameters for scaling dialysis dose include body weight (W(0.67)), body surface area (BSA), resting energy expenditure (REE), high metabolic rate organ (HMRO) mass, liver size (LV), and bioelectrical resistance (R).
• Bioelectrical resistance (R) is a measurable biological parameter proposed for more accurate dialysis dose scaling.

Purpose of the Study:

• To prospectively evaluate the predictive power of various demographic, anthropometric, bioelectrical, and biochemical parameters on long-term survival in incident HD patients.
• To compare the efficacy of seven different scaling parameters (Vurea, W(0.67), BSA, REE, HMRO, LV, R) and eight HD adequacy indices in predicting patient outcomes.
• To identify reliable indicators of dialysis adequacy that correlate with long-term survival.

Main Methods:

• A cohort of 328 incident white HD patients was studied.
• Periodic biochemical evaluations and single-frequency bioelectrical impedance analysis (BIA) measurements were conducted every three months.
• Cox regression and Kaplan-Meier survival analyses were used to assess the predictive power of different parameters on long-term survival.

Main Results:

• Higher serum creatinine (Scr) levels and lower Kt/R values were initially identified as significant outcome predictors.
• In a subsequent analysis, higher Scr levels and higher bioelectrical resistance (R) values emerged as significant predictors of long-term survival.
• Kaplan-Meier analyses confirmed significantly higher long-term survival for patients with R values above the first quartile, Kt/R values below the fourth quartile, and Scr levels above the first quartile.

Conclusions:

• Kt/R, bioelectrical resistance (R), and serum creatinine (Scr) are independent predictors of long-term survival in incident HD patients.
• Bioelectrical resistance (R) reflects fluid status, while Scr indicates lean body mass, suggesting body composition is more critical than traditional measures like body weight or BMI for dialysis adequacy.
• Further research is needed to refine these findings into clinical outcome-based adequacy targets for HD treatment.