In dialysis, what does Kt/V measure and what is the typical target per hemodialysis session?

• A. Blood flow rate
• B. Urine output
• C. Dialysis dose/adequacy; target around 1.2 per session
• D. Volume of ultrafiltration

Answer: (C)

Kt/V measures dialysis dose, reflecting how effectively a session clears small solutes relative to the patient’s body water. K is the dialyzer clearance of urea, t is the treatment time, and V is the volume of distribution for urea (roughly total body water). In practice, this index is used to gauge adequacy of solute removal across a dialysis session. The typical target for a standard thrice-weekly hemodialysis session is about 1.2, meaning a substantial fraction of the body’s urea burden is cleared during the session.

The other factors aren’t about overall solute clearance relative to body water: blood flow rate affects how quickly blood is processed but doesn’t by itself quantify how much of the body’s solute burden is cleared; urine output is a measure of residual kidney function, not dialysis adequacy; and ultrafiltration volume concerns fluid removal, not solute clearance.