MedCalc: Hemodialysis - Kt/V and URR

Height : Weight : Age : Gender : Dialyzer UreaClearance (K) : L/min Dialysis Time (t) : minutes hours cm meters inches feet kilograms pounds years female male no yes Urea Volume Distrib (V) Watson formula Hume-Weyer formula Bioelectrical impedance Mellits-Cheek formula (kids) 0.6 x weight : liters Kt/V :
Pre-dialysis BUN : mg/dL mg/dL kilograms pounds liters %

Watson : Male TBW = 2.447 - (0.09156 x age) + (0.1074 x height) + (0.3362 x weight)
Female TBW = -2.097 + (0.1069 x height) + (0.2466 x weight)
Hume-Weyers : Male TBW = (0.194786 x height) + (0.296785 x weight) - 14.012934
Female TBW = (0.34454 x height) + (0.183809 x weight) - 35.270121
Chertow's Bioelectrical Impedance:
TBW = ht x (0.0186104 x wt + 0.12703384) + wt x (0.11262857 x male + 0.00104135 x age - 0.00067247 x wt - 0.04012056) - age x (0.03486146 x male + 0.07493713) - male x 1.01767992 + diabetes x 0.57894981
Mellits-Cheek (kids) : Boys TBW = -1.927 + 0.465 x weight + 0.045 x height, for height < 132.7 cm
= -21.993 + 0.406 x weight + 0.209 x height, for height > 132.7 cm
Girls TBW = 0.076 + 0.507 x weight + 0.013 x height, for height < 110.8 cm
= -10.313 + 0.252 x weight + 0.154 x height, for height > 110.8 cm
Urea Reduction Ratio : URR = (1 -
 post-BUN ) x 100 pre-BUN
Daugirdas : Kt/V = -ln(
 post-BUN - 0.03) + (4 - 3.5 x post-BUN ) x UF   pre-BUN pre-BUN weight
Hume R, Weyers E. Relationship between total body water and surface area in normal and obese subjects. J Clin Pathol 24:234-238, 1971.
Watson PE, Watson ID, Batt RD. Total body water volumes for adult males and females estimated from simple anthropometric measurements. Am J Clin Nutr 33:27-39, 1980.
Chertow GM, Lowrie EG, Lew NL, Lazarus JM. Development of a population-specific regression equation to estimate total body water in hemodialysis patients. Kid Int 51:1578-1582, 1997.
Daugirdas JT. Second generation logarithmic estimates of single-pool variable volume Kt/V: an analysis of error. J Am Soc Nephrol 4:1205-1213, 1993.

Created: Monday, November 5, 2001