Table 2.

Comparison of modalities by theoretic maximal clearances and estimated weekly dosages

Modality	Maximal Theoretic Clearance (ml/min)	Approximate Total Weekly Dose (standardized Kt/Vurea)
Intermittent HD, 3 times/wk	280	2
Intermittent HD, 7 times/wk	280	5
CKRT, postfilter CVVH, 25 ml/kg per hour	25	7
CKRT, prefilter CVVH, 35 ml/kg per hour	28	8
CKRT, postfilter CVVH, 35 ml/kg per hour	35	10
CKRT, CVVHD, 35 ml/kg per hour	35	10
Normal kidney	90–140	16

Clearance values represent theoretic maximums, assuming hematocrit of 30%, body weight of 60 kg, body water of 36 L, intermittent HD blood flow rate of 400 ml/min, CKRT blood flow rate of 200 ml/min, sieving coefficient of one, and dialysate saturation (i.e., extraction ratio) of 100%. Estimated Kt/V values for CKRT similarly assume theoretic maximal values, with no downtime, filter efficiency loss, or patient fluid overload. Standardized Kt/V values for intermittent HD assume single-pool Kt/V of 1.3, representing typical goal clearance rather than maximal theoretic achievable clearance. HD, hemodialysis; CKRT, continuous KRT; CVVH, continuous venovenous hemofiltration; CVVHD, continuous venovenous hemodialysis. Adapted from refs. 22, 23, and 24, with permission.