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## Enter Data Below

Patient Name:    Room:
Age:
Scr:     Height:

## Background:

 Program is based on the following equations: Schwartz equation:      CrCl (ml/min/1.73m2)=  [length (cm) x k] / Scr (Patient population: infants over 1 week old through adolescence (18 years old)) k = 0.45 for infants 1 to 52 weeks old k = 0.55 for children 1 to 13 years old k = 0.55 for adolescent females 13-18 years old k = 0.7 for adolescent males 13-18 years old Schwartz GJ, Haycock GB, Edelmann CM Jr, Spitzer A: A simple estimate of glomerular filtration rate in children derived from body length and plasma creatinine. Pediatrics 58:259-263, 1976. Updated Schwartz ("Bedside Schwartz") formula: eGFR = 0.413 x (height/Scr) if height expressed in centimeters             or 41.3 x (height/Scr) if height expressed in meters eGFR (estimated glomerular filtration rate) = mL/min/1.73 m2 This equation was updated in 2009 and is the best method for estimating GFR in children from 1 to 18 years old.  This equation assumes the use of creatinine methods with calibration traceable to IDMS. The Schwartz formula was devised in the mid-1970s to estimate GFR in children. Recent data suggest that this formula currently overestimates GFR as measured by plasma disappearance of iohexol, likely a result of a change in methods used to measure creatinine. Source:  Schwartz GJ, Muñoz A, Schneider MF, et al. New equations to estimate GFR in children with CKD. J Am Soc Nephrol. 2009;20(3):629-37. Shull et al: Crcl (ml/min/1.73m2) = ((0.035 x age) + 0.236) x 100)/ Scr   Shull BC, Haughey D, Koup JR, Baliah T, Li PK. A useful method for predicting creatinine clearance in children. Clin Chem. 1978 Jul;24(7):1167-9. Counahan-Barratt: GFR (ml/min/1.73m2) = ( 0.43 x length )/ Scr Counahan R, Chantler C, Ghazali S, Kirkwood B, Rose F, Barratt TM.  Estimation of glomerular filtration rate from plasma creatinine concentration in children. Arch Dis Child. 1976 Nov;51(11):875-8.

## Important Considerations:

Clinical application and reliability.  Several factors can reduce the accuracy of creatinine clearance predictive models such as concomitant disease states and medical procedures. The article below represents a common theme found in several other studies that examine the clinical utility of the various CRCL predictive models when complicating factors exist.

Jacobson P, West N, Hutchinson RJ.  Predictive ability of creatinine clearance estimate models in pediatric bone marrow transplant patients.  Bone Marrow Transplant. 1997 Mar;19(5):481-5.
"In the majority of children, models overestimated CrCl. The tested models did not accurately predict CrCl and did not provide a reliable alternative to measured CrCl."   (Models assessed: Traub and Johnson, Schwartz et al, Counahan et al, modified Counahan et al, Ghazali and Barratt, Shull et al and Dechaux et al. )

Ideally a 24 hour urine collection and a mid-point serum creatinine  should be obtained. This method is the most accurate clinical measure of creatinine clearance.

The Schwartz method, like several other CRCL predictive models, attempts to estimate (not calculate) the creatinine clearance. It is important to remember that the result listed above should be considered a rough estimate of the CRCL.  Also, it is assumed that the serum creatinine is at steady state. If the patient's renal function is declining you must wait until steady state occurs or you will overestimate the clearance. The opposite occurs if the patient's renal function is improving.

Counahan R, Chantler C, Ghazali S, Kirkwood B, Rose F, Barratt TM.  Estimation of glomerular filtration rate from plasma creatinine concentration in children. Arch Dis Child. 1976 Nov;51(11):875-8.

Schwartz GJ, Haycock GB, Edelmann CM Jr, Spitzer A: A simple estimate of glomerular filtration rate in children derived from body length and plasma creatinine. Pediatrics 58:259-263, 1976.

Shull BC, Haughey D, Koup JR, Baliah T, Li PK. A useful method for predicting creatinine clearance in children. Clin Chem. 1978 Jul;24(7):1167-9.
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