Creatinine Clearance

From Anvita Health Wiki

Contents 1 Indications 2 Principle 3 Decreases 4 More General Terms 5 Additional Terms 6 References

Indications

• evaluation of renal disease

Principle

• the creatinine clearance is determined by a 24 hour urine for creatinine along with serum creatinine according to the following equation:

*               Creatinine [urine] (mg/dL) x volume (mL) 
*               ---------------------------------------- 
*               Creatinine [serum] (mg/dL) x minutes

• the creatinine clearance is often estimated using a patient's age, weight & sex according to the Cockcroft-Gault equation.

<br>  
*                [140 - age] x weight* (kg) 
*              -------------------------------    x 0.85 for women 
*              72 x creatinine [serum] (mg/dL) 

• * ideal body weight

• creatinine clearance overestimates glomerular filtration because of tubular secretion of creatinine
• use of cimetidine (400 mg PO TID or 800 mg QHS) suppresses the tubular secretion of creatinine, thus giving a better estimate of the true creatinine clearance

Decreases

• renal insufficiency
• renal failure

More General Terms

• clinical chemistry test
• renal function tests; renal function panel

Additional Terms

• 24 hour urine creatinine
• creatinine in serum/plasma

References

1. Manual of Medical Therapeutics, 28th ed, Ewald & McKenzie (eds), Little, Brown & Co, Boston, 1995, pg 262
2. Medical Knowledge Self Assessment Program (MKSAP) 11, American College of Physicians, Philadelphia 1998

creatinine clearance