Dialysis—Reply

In Reply We thank Dr Cohen for his comments. We agree that the “adequacy” of dialysis measured by urea removal is an important concept, relevant to both nephrologists and general medicine clinicians. Due to space limitations, we were unable to include this topic in our Review. Of note, the appropriateness of the term adequacy has been questioned in recent years. Measures of small solute (ie, urea) removal do not capture potassium or acid-base homeostasis, fluid or middle molecule (ie, molecules weighing 500-15 000 Da, such as beta-2 microglobulin and endotoxin fragments) removal, or patient-prioritized outcomes, such as symptoms and quality of life. Experts now recognize the insufficiency of urea clearance as an adequacy marker and recommend characterizing optimal dialysis by patient-reported and clinical measures. Guidelines support individualizing dialysis care, endorsing a goal-directed approach that incorporates patient priorities and preferences while maintaining quality and safety. Measures of urea removal remain important parameters to consider, but such laboratory values should not be used in isolation when prescribing the length of hemodialysis treatments and the number of peritoneal dialysis exchanges.