On the Efficiency of Center-Based Dialysis
The typical dialysis center experience targets a urea clearance value of KT/V = 1.4 (KT/V is explained by Dean here). We can use this knowledge to solve for the clearance rate of a typical dialysis center experience. Assuming 40 L of blood (body weight is about 60% water so this corresponds to 145 lbs,) 4 hours of dialysis. and a blood flow rate of 500 ml/min through the dialysis machine …
K = (1.4×40000 ml)/(4 hr x 60 min/hr)
K = 233 ml/min
e = (233 ml/min)/(500 ml/min)
e = 46%
This efficiency is also the concentration reduction expected for a single pass through the dialyzer. For comparison, Dean is seeing e ~ 30% reduction in his benchtop experiments. Dean’s experiments were done for a 15 mm path whereas actual dialysis membranes are 250 mm in length.