Kt/V requires four factors. Which are they?

• A. Height, weight, fill volume and amputation documentation
• B. Age, sex, dialysis time, and blood pressure
• C. Hematocrit, albumin, interdialytic weight gain, urea
• D. Dialysate calcium, magnesium, potassium, bicarbonate

Answer: (A)

Kt/V measures how effectively a dialysis dose removes a small solute (urea) relative to the patient’s body water. The four factors that determine it are:

• K: the urea clearance by the dialysis process (how fast urea is removed)

• t: the time over which dialysis occurs (the dwell or exchange duration)

• V: the volume of distribution, essentially total body water (larger V lowers Kt/V for a given clearance and time)

• urea: the solute used to quantify the dose (the amount removed is referenced to urea)

None of the answer choices list all four factors together. The closest relevant component is the inclusion of dialysis time, which corresponds to the time factor, but the full four factors are K, t, V, and urea.