Dose of dialysis: what index?

Area of Science:

• Nephrology
• Renal Replacement Therapy
• Clinical Medicine

Background:

• Increasing mortality in hemodialysis (HD) patients in the US is not fully explained by wider acceptance criteria.
• Concerns exist regarding current HD treatment time and dose standards, prompting re-evaluation of HD adequacy.
• This study investigates long-term patient survival using traditional HD methods.

Purpose of the Study:

• To analyze patient survival in a cohort treated with unchanged, older hemodialysis methods over 22 years.
• To compare survival data with major HD registries and evaluate survival based on mean arterial pressure (MAP), urea fractional clearance (Kt/V), and middle-molecule dialysis index (DI).

Main Methods:

• Retrospective analysis of 445 unselected patients treated with consistent HD methods (24 m2/week, flat-plate dialyzers, cuprophane membrane, acetate buffer) for 22 years.
• Survival data compared to national/international HD registries.
• Statistical analysis using Kaplan-Meier (log-rank test) and Cox proportional hazard models.

Main Results:

• The study cohort demonstrated superior short- and long-term survival compared to major HD registries, particularly in older patients.
• Favorable survival correlated with good MAP control without medication, higher Kt/V (1.67 ± 0.41), and DI (1.47 ± 0.38).
• Cox analysis indicated survival was linked to MAP, with potential improvement from DI > 1.38 but not necessarily Kt/V > 1.60.

Conclusions:

• Adequate hemodialysis involves sufficient small- and middle-molecule diffusion, ultrafiltration, and arterial pressure control without antihypertensive medication.
• Long-term satisfactory survival is the most reliable indicator of overall dialysis adequacy.
• Traditional HD methods, when optimized for comprehensive parameters, can yield excellent patient survival.