Accuracy of modification of diet for renal disease and cockcroft-gault equations as compared to the radioisotope double sample method: a study in patients with acute renal failure

We intended to assess the accuracy of re-expressed Modification of Diet for Renal Disease [MDRD] and Cockcroft-Gault [CG] equations to estimate glomerular filtration rate [GFR] in chronic kidney disease in two different etiologies of acute renal failure [ARF]: acute tubular necrosis [ATN] and acute glomerulonephritis [AGN]. Patients admitted for ARF or the patients complicated with ARF during the course of their hospitalization were enrolled to the study [n=21; 14 females and 7 males; 11 ATN and 12 AGN]. When the plasma creatinine reached a steady state [DPSM] using [99m]Tc-DTPA. GFR was also estimated by MDRD [GFRMDRD] and CG [GFRCG] equations. The patients aged 44.8 +/- 19.5 years and weighted 67.8 +/- 10.7kg. GFRDPSM [32.9 +/- 14.7 ml/min] was statistically different from the GFRMDRD [11.6 +/- 8.2 ml/min; pCG was lower than GFRDPSM in patients with either ATN [16.5 +/- 12.5ml/min and pDPSM and GFRMDRD [r=0.34; p=0.13] but GFRDPSM and GFRCG values were correlated [r=0.48; p=0.03]. Out of subjects with GFRDPSM >30, 92.3% had GFRMDRDCG Our results indicate that MDRD and CG equations were substantially inaccurate in patients with ARF. More precise methods of GFR evaluation is recommended in these patients