105 - Glomerular filtration rate measurement: from equations to report consensus
Autore/i: D. Giavarina
Rivista: RIMeL - IJLaM, Vol. 5, N. 3-S1, 2009 (MAF Servizi srl ed.)
Pagina/e: 105
In the clinical assessment of kidney function a simple measure of solute concentration or solute excretion or urine output does not describe the real “function” of the organ, since urinary flow, body size and solute concentration in blood could be very different between individuals. The Glomerular Filtration Rate (GFR), i.e. flow rate of filtered fluid through the kidney, is considered the best overall index of kidney function both in health and disease. The GFR cannot be measured easily in clinical practice. It takes an integration of many parameters, in a balance between capillary and interstitial hydrostatic and oncotic pressure. In practice, it is not possible to directly identify the needed values for this equation. The “clearance” of an ideal molecule, fully filtered by the glomerular membrane, without reabsorpion or secretion by renal tubuli, could be a way to compare renal function among different individuals. But the “ideal” marker does not exist and many exogenous molecules currently used are expensive, complex or lead to error of 5-20% in different measurements. Since seventies, a number of formulas have been devised to estimate GFR values on the basis of serum creatinine levels….