What is the range of centrally infused protein losses into CRRT effluent?

• A. 5-10%
• B. 18-25%
• C. 10-17%
• D. 30-40%

Answer: (C)

Protein losses into the CRRT effluent come from small plasma proteins that cross the filter under the influence of diffusion and convection. Large proteins like albumin are largely retained by the membrane, so the losses are driven by smaller proteins and peptides that pass through more readily. Under typical CRRT settings with standard high-flux membranes, the amount of protein lost is about 10-17% of the patient’s daily protein intake. This is why nutrition support for patients on CRRT often includes additional protein to cover these losses and maintain net protein balance. The exact percentage can vary with higher effluent rates or more permeable membranes, which can push losses toward the upper end of this range.