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Anthropometric formulas
Adults Lean body weight (LBW)
Devine equation: LBW (Males) = 50 + [ 2.3 x (60  Height in inches) ] LBW (Females) = 45.5 + [ 2.3 x (60  Height in inches) ]
Hume equation: LBW (Males) = (0.3281 x Weight in kg) + (0.33939 x Height in cm)  29.5336 LBW (Females) = (0.29569 x Weight in kg) + (0.41813 x Height in cm)  43.2933
The Devine method is the default result. For short stature patients (less than 60 inches), the Hume method is utilized when its result is less than baseline LBW (50kg for males, 45.5kg for females) and greater than Devine.
Please note that neither of these method is valid in amputees.
Body surface area (BSA)
Mosteller equation: BSA = Square root of (HT X WT) / 3600 where HT = height in centimeters WT = weight in kilograms
Serum Creatinine Adjustement for IDMS CREAT
If your laboratory utilizes the IDMS traceable creatinine, the serum creatinine must be adjusted in order to use older equations such as Cockroft and Gault:
NonIDMS SrCr (mg/dL) = IDMS CREAT (mg/dL) x 1.065 + 0.067
Creatinine Clearance (CrCl) per Cockroft and Gault
The default method uses Lean Body Weight. The reason for this is, creatinine is a byproduct of muscle metabolism, not fat. Therefore, excess weight, in the form of fat, does not significantly affect the production of creatinine
You may optionally choose to calculate with an Adjusted body weight:
1. Calculate body weight adjusted for obesity* (ABW) ABW = LBW + [0.3 x (WTLBW)] where WT = actual body weight in kg LBW = lean body weight in kg
*Obesity defined as BMI > 30.
2. Calculate creatinine clearance (CrCl) CrCl Males = [ABW x (140  Age)] / (SrCr x 72) CrCl Females = 85% of male value where SrCr = the most recent serum creatinine in mg/dL ABW = adjusted body weight in kg
Note: For optional CrCl methods, please see the help topic Other Creatinine Clearance Methods.
Pediatrics Lean body weight (LBW)
Traub equation: LBW = (HT2 x 1.65)/1000 where HT = height in centimeters
Body surface area (BSA)
Haycock equation: BSA = 0.024265 x HT 0.3964 x WT 0.5378 where HT = height in centimeters WT = weight in kilograms
Creatinine Clearance (CrCl) per Schwartz
CrCl = (k x HT/SrCr) x (1.73/BSA) where HT = height in centimeters SrCr = the most recent serum creatinine in mg/dL k = 0.33 if weight < 2.5 kg k = 0.45 if age <1 year k = 0.55 if age 112 years

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