Dose of Continuous Renal Replacement Therapy in Critically Ill Patients: A Bona Fide Quality Indicator

Abstract

Acute kidney injury (AKI) is common in critically ill patients, and renal replacement therapy (RRT) constitutes an important aspect of acute management during critical illness. Continuous RRT (CRRT) is frequently utilized in intensive care unit settings, particularly in patients with severe AKI, fluid overload, and hemodynamic instability. The main goal of CRRT is to timely optimize solute control, acid-base, and volume status. Total effluent dose of CRRT is a deliverable that depends on multiple factors and therefore should be systematically monitored (prescribed vs. delivered) and iteratively adjusted in a sustainable mode. In this manuscript, we review current evidence of CRRT dosing and provide recommendations for its implementation as a quality indicator of CRRT delivery.

Keywords: Acute kidney injury; Continuous renal replacement therapy; Dose; Quality indicator; Quality metric.

Figure 1:

Conceptual difference between prescribed and delivered CRRT dose

Figure 2:

Quality indicators related to delivered CRRT dose. A) Clearance of urea nitrogen delivered with CRRT can be measured by the ratio of effluent urea nitrogen to blood urea nitrogen (arterial port) and should be maintained above 0.8 on average; B) The ratio of delivered to prescribed CRRT dose should be also maintained above 0.8 on average; C) Change in blood concentrations of small solutes (e.g., urea nitrogen) evaluated in 24-hour cycles can also indicate CRRT adequacy for solute removal; D) Time on CRRT is a critical aspect to effectively deliver the prescribed CRRT dose.