Abstract
Background: Dialysis adequacy indices are based on the amount of removed solute and systemized into two groups: (1) fractional solute removal (FSR, non-dimensional), and (2) equivalent continuous clearance (ECC, ml/min), which are expressed using appropriate reference method for solute concentration or mass such as: peak, peak average, time average, and treatment time average values. Methods: A review and critical analysis of the recent studies was performed. Results: The indices are mathematically interrelated and depend on kinetic parameters of the treatment, as device clearance, treatment time, solute distribution volume, dialysis frequency. In particular, KT/V and KT can be directly translated to FSR and ECC using the treatment time average reference method. Conclusion: The diverse family of dialysis adequacy indices can be understood as one integrated system and be useful when assessing both standard treatment modalities and newer schedules and modalities (frequent dialysis, hybrid dialysis, dialysis in acute renal failure) of renal replacement therapies.