Renal function

Jump to: navigation, search

WikiDoc Resources for Renal function


Most recent articles on Renal function

Most cited articles on Renal function

Review articles on Renal function

Articles on Renal function in N Eng J Med, Lancet, BMJ


Powerpoint slides on Renal function

Images of Renal function

Photos of Renal function

Podcasts & MP3s on Renal function

Videos on Renal function

Evidence Based Medicine

Cochrane Collaboration on Renal function

Bandolier on Renal function

TRIP on Renal function

Clinical Trials

Ongoing Trials on Renal function at Clinical

Trial results on Renal function

Clinical Trials on Renal function at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Renal function

NICE Guidance on Renal function


FDA on Renal function

CDC on Renal function


Books on Renal function


Renal function in the news

Be alerted to news on Renal function

News trends on Renal function


Blogs on Renal function


Definitions of Renal function

Patient Resources / Community

Patient resources on Renal function

Discussion groups on Renal function

Patient Handouts on Renal function

Directions to Hospitals Treating Renal function

Risk calculators and risk factors for Renal function

Healthcare Provider Resources

Symptoms of Renal function

Causes & Risk Factors for Renal function

Diagnostic studies for Renal function

Treatment of Renal function

Continuing Medical Education (CME)

CME Programs on Renal function


Renal function en Espanol

Renal function en Francais


Renal function in the Marketplace

Patents on Renal function

Experimental / Informatics

List of terms related to Renal function

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor-In-Chief: Cafer Zorkun, M.D., Ph.D. [2]


In medicine (nephrology) renal function is an indication of the state of the kidney and its role in physiology.

Indirect markers

Most doctors use the plasma concentrations of creatinine, urea, and electrolytes to determine renal function. These measures are adequate to determine whether a patient is suffering from kidney disease.

Unfortunately, BUN and creatinine will not be outside the normal range until 60% of total kidney function is lost. Hence, creatinine clearance is a more accurate measure and is used whenever renal disease is suspected or careful dosing of nephrotoxic drugs is required.

Glomerular filtration rate

In renal patients, the glomerular filtration rate (GFR) is used. This is calculated by comparing urine creatinine levels with the blood test results. It gives a more precise indication of the state of the kidneys. The GFR is expressed in ml/min. For most patients, a GFR over 60 ml/min is adequate. But, if the GFR has significantly declined from a previous test result, this can be an early indicator of kidney disease requiring medical intervention. The sooner kidney dysfunction is diagnosed and treated, the greater odds of preserving remaining nephrons, and preventing the need for dialysis.

Very often, the GFR is expressed as ml/min/1.73 m2. This is an indication that the GFR needs to be corrected for the body surface area (BSA). While most adults have a BSA that approaches 1.7 (1.6-1.9), extremely obese or slim patients should have their GFR corrected for their actual BSA.

BSA can be calculated on the basis of weight and height.

Cockcroft-Gault formula

A commonly used surrogate marker for actual creatinine clearance is the Cockcroft-Gault formula, which employs creatinine measurements and a patient's weight to predict the clearance. The formula, as originally published, is:

This formula expects weight (actually mass) to be measured in kilograms and creatinine to be measured in mg/dL, as is standard in the USA. The resulting value is multiplied by a constant of 0.85 if the patient is female. This formula is useful because the calculations are relatively simple and can often be performed without the aid of a calculator.

A modification of this formula, useful for the common units of measure, is:

This formula uses metric units (weight in kilograms, creatinine in µmol/L). The constant is 1.23 for men and 1.04 for women.

It is named after the scientists who first published the formula (Cockcroft & Gault, 1976). The equation is popular because it is easy to calculate.

MDRD formula

The most recently advocated formula for calculating the GFR is the one that was developed as a result of the Modification of Diet in Renal Disease (MDRD) study (Levey et al 1999).

For creatinine in mg/dL

For creatinine in µmol/L

The constant is 1 for a white male, and is multiplied with 0.742 for females and multiplied with 1.21 for African Americans.

Creatinine levels in µmol/L can be converted to mg/dL by dividing them by 88.4. The 32788 number above is equal to 186×88.41.154.

A more elaborate version of the MDRD equation also includes serum albumin and blood urea nitrogen levels:

Children: Schwartz

In children, the Schwartz formula is used. This employs the serum creatinine, the child's height and a constant to estimate the creatinine clearance.

k - for height in some units and creatine in some other units, the constant is 0.33-0.45 in infants, 0.55 in children or adolescent girls, or 0.70 in adolescent boys.


See also

External links