Renal function - Wikipedia
GFR is Glomerular Filtration Rate and it is a key indicator of renal function. eGFR derived entity based on a patient's serum creatinine level, age, sex and race. Stevens et al1 suggest that the Modification of Diet in Renal Disease (MDRD) Study equation for estimated glomerular filtration rate (GFR) is an acceptable. The kidneys' ability to handle creatinine is called the creatinine clearance rate, which helps to estimate the glomerular filtration rate (GFR) -- the.
Creatinine Clearance (Cockcroft-Gault Equation) - MDCalc
It is not applicable in children. Most laboratories in New Zealand now automatically report eGFR whenever a serum creatinine is requested. This allows the practitioner to assess kidney function without having to estimate creatinine clearance using the Cockcroft-Gault equation.
Provision of the eGFR allows an initial screen for chronic kidney disease and the possibility of early detection.How To Read Kidney Blood Test Result (GFR, Creatinine, Creatinine Clearance Test, Potassium Sodium)
Ethnicity factors have not yet been calculated for other ethnic groups. This gives a convenient method of consistent reporting of eGFR which can be related to renal function and stages of CKD.
An online and downloadable eGFR calculator is available from http: The indications for referral to a nephrologist are: This is especially important in populations at high risk of renal disease in which the MDRD equation has not been validated e.
These are; Acute changes in kidney function e.
Creatinine Clearance Calculator
Paraplegia, amputees and those with very high muscle mass. Age less than 18 years. The use of eGFR has not been validated for the adjustment of drug dosages.
The Cockcroft-Gault equation is still recommended for this. This means there could be significant differences in the two values in people at extremes of body size.
Serum creatinine production is approximated based on lean body weight because muscle tissue not fat is responsible for creatine production. Furthermore, a change in total body mass does not increase the size of the kidney or GFR proportionally.
Equations that do not correct or adjust for obesity risk overestimation of true renal function. In one of the largest study on the topic to date of nearly overweight and obese patients, the following conclusions can be drawn: In the process of conversion, however, the non-normalized value will also overestimate GFR in obese patients.
This equation was not scientifically derived or validated, 15 but is extensively used in medicine. A newer equation, called LBW 19 may be a more promising estimation of lean body weight and has been derived and validated with actual patient data. Intuitively, this practice does not make sense because rounding a serum creatinine of 0.
The literature does not support this practice as it often results in an underestimation of true renal function.
best practice 6, June Renal Update
Rounding Creatinine in Underweight Patients In underweight patients, a low serum creatinine may be more reflective of a decrease in production rather than an increased rate of renal elimination. Similarly to elderly patientsclinicians may be tempted to round creatinine in underweight patients to account for less muscle mass; however, this practice is not supported by the literature.
This correction factor was shown to be more precise and less bias than rounding or making no adjustment.
- Renal function
Medications that Modify Serum Creatinine Because serum creatinine undergoes tubular secretion, any medications that interfere with this process will falsely elevate the patient's serum creatinine; however, this will not impact the patient's true GFR.