What is the optimal dialysate dose in Continuous Renal Replacement Therapy (CRRT)?

From the Guidelines

The optimal dialysate dose in Continuous Renal Replacement Therapy (CRRT) is 20-25 mL/kg/h.

Key Considerations

• This dose is recommended to achieve the goals of electrolyte, acid-base, solute, and fluid balance that will meet the patient’s needs 1.
• The prescription of effluent volume should be adjusted frequently to ensure the actual delivered dose meets the patient’s needs 1.
• The use of bicarbonate as a buffer in dialysate and replacement fluid is recommended, rather than lactate, especially in patients with circulatory shock or liver failure and/or lactic acidemia 1.

Clinical Context

• The choice of CRRT modality should be tailored to the patient's clinical status, with consideration of hemodynamic stability and the presence of conditions such as acute brain injury or increased intracranial pressure 1.
• The dose of CRRT should be individualized based on the patient's specific needs, with regular assessment and adjustment of the prescription as needed 1.

Evidence Base

• The recommendations for CRRT dose are based on the 2012 KDIGO clinical practice guideline for acute kidney injury, which suggests delivering an effluent volume of 20-25 mL/kg/h for CRRT in AKI 1.
• More recent studies have supported the use of this dose, with consideration of individual patient needs and clinical context 1.

From the Research

Optimal Dialysate Dose in CRRT

The optimal dialysate dose in Continuous Renal Replacement Therapy (CRRT) is a topic of ongoing debate. Several studies have investigated the relationship between CRRT dose and clinical outcomes in patients with acute kidney injury (AKI).

• The dose of CRRT is typically reported as effluent flow in mL/kg body weight per hour (mL/kg/h) 2, 3, 4.
• Recent clinical trials have suggested that higher-intensity CRRT does not improve outcomes in patients with AKI, and that an effluent flow rate of 20-25 mL/kg/h is sufficient 2, 4.
• However, some studies have found that more-intensive CRRT may be associated with shorter ICU stays and durations of mechanical ventilation among survivors 5.
• The delivered dose of CRRT should be routinely monitored to ensure that it is achieved, and quality measures for monitoring delivered dose have been proposed 3, 4, 6.
• The optimal dose of CRRT may need to be adjusted based on individual patient needs, and a dynamic and precise approach to dose prescription is recommended 3, 4.

Key Findings

• The ATN and RENAL studies found that effluent flow rates above 25 mL/kg/h do not improve outcomes in patients with AKI 2.
• A study published in Seminars in Dialysis recommended a prescribed CRRT effluent dose of 25-30 mL/kg/h to account for treatment interruptions and filter efficiency decline 3.
• A study published in Gaceta Medica de Mexico found that a prescribed dose of 20-25 mL/kg/h is recommended based on recent clinical trials 4.
• A study published in Critical Care found that more-intensive RRT was associated with shorter ICU stays and durations of mechanical ventilation among survivors, but did not improve survival 5.
• A study published in Nephron recommended that the dose of CRRT be systematically monitored and iteratively adjusted as a quality indicator of CRRT delivery 6.