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Other Creatinine Clearance Methods

 

Click the "Other" button on the Patient data tab to select from alternate creatinine clearance methods.

 

Select the calculation method, then "Copy" to transfer the value to the patient data tab.

 

Click "Cancel" to close the window without copying the value to the patient data tab.

 

Cockcroft and Gault TBW

This variation of the C&G equation uses Total Body Weight instead of Adjusted Body Weight.  Be aware however, that this tends to over-estimate CrCl in larger patients.

CrCl Males = TBW(140 - Age) / (SCr x  72)

CrCl Females = 85% of male value

 

 

Cockcroft and Gault Normalized

Removes weight from the C&G equation.  Some find this variation useful in patients whose body size differs substantially from average.

CrCl Males = (140 - Age) / SCr

CrCl Females = 85% of male value

 

 

Jelliffe Multi-step

1.   Estimate urinary creatinine excretion rate

E (males) = LBW x (29.305 -[0.203 x (age)])

E (females) = LBW x (25.3 -[0.18 x (age)])

 

2.   Correct for rising serum creatinine

E = E - [4 x LBW x (SCr1-SCr2)] / D

where LBW = lean body weight in kilograms

 Scr1= the latest serum creatinine

 Scr2= the earlier serum creatinine

 D = the number of days between

 

3.   Calculate corrected creatinine clearance (CrCl)

 CrCl/1.73 m2 =  (E * 0.12) / (SrCr * BSA)

 where SrCr is the most recent serum creatinine

 

 

Jelliffe 1973

Weight is not used in this equation either, therefore, some find this method useful in patients whose body size is substantially different from average:

CrCl Males = 98 - (0.8 x (Age-20)) / Scr

CrCl Females = 90% of male value

 

 

MDRD (abbreviated)

Derived from a large study of patients with a wide range of kidney function.  Some feel this is a more accurate GFR method overall.

GFR Males = exp[ 5.228 - ( 1.154 x  log{SCr} )  - ( 0.203  x  log{Age} )

GFR Female = 74.2% of male value

For African Americans multiply by 1.21

 

It is important to note that MDRD calculates GFR which does not directly correlate to CrCl

 

Salazar and Corcoran

Derived from a study of obese patients.  Some recommend this method for obese patients instead of the standard equations.

CrCl Males  =  { ( 137 - Age ) x [ ( 0.285 x Wt)  + (12.1 x Ht^2 )] }  /  (51 x SCr)

CrCl Females  = { ( 146 - Age ) x [ ( 0.287 x Wt)  + (9.74 x Ht^2 )] }  /  (60 x SCr)

 

References

 

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