Renal Functional Reserve and Renal Recovery after Acute Kidney Injury

Renal functional reserve (RFR) represents the capacity of the kidney to increase glomerular filtration rate (GFR) in response to certain physiological or pathological stimuli or conditions. Once baseline GFR is determined, RFR can be assessed clinically after an oral protein load or intravenous amino acid infusion. In clinical practice, baseline GFR displays variable levels due to diet or other factors. RFR is the difference between peak ‘stress’ GFR induced by the test (p.o. or i.v.) and the baseline GFR. In clinical scenarios where hyperfiltration is present (high baseline GFR due to pregnancy, hypertension or diabetic nephropathy, in solitary kidney or kidney donors), RFR may be fully or partially used to achieve normal or supranormal renal function. Since commonly used renal function markers, such as GFR, may remain within normal ranges until 50% of nephrons are lost or in patients with a single remnant kidney, the RFR test may represent a sensitive and early way to assess the functional decline in the kidney. RFR assessment may become an important tool to evaluate the ability of the kidney to recover completely or partially after a kidney attack. In case of healing Published online: September 24, 2014 Prof. Claudio Ronco Department of Nephrology and IRRIV San Bortolo Hospital IT–36100 Vicenza (Italy) E-Mail cronco @ goldnet.it © 2014 S. Karger AG, Basel 1660–2110/14/1274–0094$39.50/0 www.karger.com/nec Targeting Recovery from Acute Kidney Injury: Round Table Conference at the 19th International Conference on Continuous Renal Replacement Therapies (Manchester Grand Hyatt, San Diego, Calif., USA, March 2–3, 2014). D ow nl oa de d by : 54 .7 0. 40 .1 1 11 /2 5/ 20 17 7 :3 0: 35 A M