![]() ![]() Timed urine collections are notoriously unreliable, inconvenient, and add to the expense of the investigation.In practice, there are limitations to this formal measurement of creatinine clearance using the 24-hour urine test, as follows: This allows the calculation of a creatinine clearance (u − Cr × V/s − Cr). The traditional way to account for differences in creatinine production is to measure the amount of creatinine in the urine by collecting 24-hour urine samples. As well, 40% of people with reduced GFR have been found to have normal serum creatinine concentrations. In order to define all these variables, the adult ranges for serum creatinine tend to be overly liberal. ![]() In the critical region where normal kidney function passes into CKD a large change in the GFR is represented by a relatively small change in the serum creatinine. The relationship between serum creatinine and glomerular function (expressed as the glomerular filtration rate) is logarithmic. The time-honored analysis of serum creatinine is efficient to perform and fulfills most of the desired physiological criteria. Actual measurement of the glomerular filtration rate (GFR) using administered inulin, radioactive 125I-iothalamate, or 99mTc-DPTA is very accurate and suitable for research and special studies, but all of the methods involved are invasive, highly expensive, and time-consuming. Serum cystatin C provides a better estimate of glomerular function, but is currently at least 10 times more costly to analyze. Serum urea is easy to analyze, but results are influenced greatly by hydration and protein intake. The eGFR has been selected as the essential marker for the new BC chronic kidney disease (CKD) clinical practice guidelines.Īn ideal routine test of glomerular function would inexpensively measure an endogenous substance that is continually and consistently released into the circulation and is removed exclusively by glomerular filtration. Because kidney disease evolves without notable signs or symptoms, a simple, reliable, objective test is required for case finding and categorizing severity. British Columbia is the first multilab jurisdiction in the world to routinely analyze serum creatinine values using an equation that provides an estimate of the glomerular filtration rate (eGFR), and the first to initiate a broad-based creatinine testing standardization program. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |