Unstable Renal Function - Creatinine Clearance Methods
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Program is used in patients with changing renal function. Requires two
SCR Values
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Patient Name:
Location:
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Age:
Sex:
Units for serum creatinine values:
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Select serum creatinine reference standard:
[more info] |
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Height:
Weight:
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Enter the time difference between the two serum creatinine
values:
Important: If
the time difference between the values is less than one day, IGNORE the
Jelliffe and Brater results. The only valid result when using
shorter intervals is the output of the Chiou equation. |
Required for 'Jelliffe and Jelliffe' equation:
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If serum creatinine values are RISING, enter the most RECENT SCR.
If SCR values are declining enter the AVERAGE VALUE between the two SCR
values:
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Required for 'Jelliffe and Jelliffe', Brater,
and Chiou
equations:
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Most recent SCR Value:
Earlier SCR Value:
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Equations
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Background equations |
Estimated IBW:
Males: IBW = 50 kg + 2.3 kg for each inch over 5 feet.
Females: IBW = 45.5 kg + 2.3 kg for each inch over 5 feet.
AjBW = adjusted body weight:
AjBW = IBW + 0.4( ABW - IBW)
BSA (m2) = 0.007184 x Height(cm)0.725 x
Weight(kg)0.425
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Jelliffe and Jelliffe |
Ess (males) = IBW x (29.3 -[0.203 x (age)])
Ess (females) = IBW x (25.1 -[0.175 x (age)])
Correct Ess for nonrenal creatinine excretion in chronic
renal failure
Esscorr = Ess x [1.035 - 0.0377(Scr)]
Scr = If serum creatinine values are RISING,
enter the most RECENT SCR. If SCR values are declining enter the
AVERAGE VALUE between the two SCR values.
E = Esscorr - [4 x IBW x (Scr2-Scr1)] /
(Time difference in days)
Scr2= latest
serum creatinine. Scr1= earlier serum creatinine.
CrCl (ml/min/1.73 M2) = E / (14.4 x Scr) |
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Brater Equation: |
CLcr (mL/min/70 kg) =
[[293 - (2.03 x age)] x [1.035 - 0.01685 x (Scr1+ Scr2)]]
/ (Scr1+ Scr2) +
[49 x (Scr1-Scr2)] / (Scr1+ Scr2)
x (Time difference in days)
Females: Male value x 0.86. |
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Chiou et al equation: |
Vd (creat) = 0.6 L/kg
Male: CLcr (mL/min) = [2 x IBW x [28 - 0.2(age)] / 14.4
x (Scr1 + Scr2) ] +
[ 2 x [Vd (Scr1 - Scr2) ] / [(Scr1 + Scr2) x (Time difference
(minutes))] ] - [Non-renal Clcr x IBW]
Female: CLcr (mL/min) = [2 x IBW x [22.4 - 0.16(age)] /
14.4 x (Scr1 + Scr2) ] +
[ 2 x [Vd (Scr1 - Scr2) ] / [(Scr1 + Scr2) x (Time difference
(minutes))] ] - [Non-renal Clcr x IBW]
Non-renal Clcr = 0.048 mL.min-1.kg-1. IBW = Ideal body weight. Scr1 =
First serum creatinine value. Scr2= Second serum creatinine value. |
References
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1) Brater DC. Drug Use In Renal Disease. ADIS Health Science Press,
Balgowlah, Australia 1983;22-56.
2) Burton, M.E., Shaw, L.M., Schentag, J.J., and Evans, W.E. (editors)
2006. Applied Pharmacokinetics & Pharmacodynamics, Principles of
Therapeutic Drug Monitoring, Lippincott Williams & Wilkins, Baltimore,
MD.
3) Chiou WL, Hsu FH. A new simnple and rapid method to monitor the renal
function based on pharmacokinetic consideration of endogenous creatinine.
Res Comm Chem Pathol Pharmacol 1975;10:315-330.
4) Devine BJ. Gentamicin therapy. Drug Intell Clin Pharm 1974;8:650-655.
5) DuBois D, DuBois DF. A formula to estimate the approximate surface
area if height and weight be known. Arch Int Med 1916;17:863-71.
6) Jelliffe RW, Jelliffe SM. A computer program for estimation of
creatinine clearance from unstable serum creatinine concentration. Math
Biosci. 1972;14:17-24.
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