| Popis: |
In 22 patients (age 19 to 73 years) the authors examined the glomerular filtration by assessing the renal clearance of 51Cr-EDTA in addition to the plasmatic method with several blood samples, methods with a smaller number of blood samples and external assessment of the radioactivity, or else by estimation of the creatinine clearance by biochemical methods. They used as the reference method assessment of the renal plasma clearance of 51Cr-EDTA by means of a one-compartment model from the radioactivity of blood samples collected during the 60th, 120th and 180th minute. It was revealed that for the normal value of glomerular filtration (GF = 1.8 ml/s) and for its reduced value (GF = 0.5 ml/s), as compared with the reference method RP, the highest external and internal accuracy, i.e. the best agreement with the reference method and the closest interval estimates, are obtained by the single sample method RE (blood sample during the 120th minute), supplemented by three external assessments of radioactivity during the 50th-70th, 110th-130th and 170th-190th minute. The regression relationship of these methods is expressed by the following equations: RE = -8.9 + 1.06 . RP; RP = 8.47 + 0.94 . RE. The biochemical methods were, as compared with the radionuclide ones, less accurate. Their accuracy declined in the order from the calculated creatinine clearance according to Cockcroft and Gault via the inverse value of the serum creatinine concentration towards the 24-hour creatinine clearance. |
