Adequacy of Continuous Renal Replacement Therapy

The concept of clearance was established more than 30 years ago as a useful tool to estimate prescribed and delivered dialysis dose in end-stage renal disease. There has been interest in applying these quantification principles for critically ill patients with acute kidney injury (AKI) also. Although continuous renal replacement therapy (CRRT) is understood to have greater solute clearance capabilities relative to intermittent therapies, neither urea nor any other solute is employed specifically for CRRT dose assessments in clinical practice. Instead, the normalized effluent rate is the gold standard for CRRT dosing, although this parameter does not provide an accurate estimation of actual solute clearance for different modalities. This chapter provides a comprehensive review of studies assessing dose prescription and delivery for CRRT. A critical review of renal replacement therapy quantification in AKI is provided, with emphasis on areas in which additional information may be useful for clinicians. An adaptation of a chronic dialysis parameter (standard Kt/V) as a benchmark to supplement effluent-based dosing is proposed to assist clinicians in the prescription and delivery of CRRT.