Estimation of chromium-51 ethylene diamine tetra-acetic acid plasma clearance: a comparative assessment of simplified techniques.
Chromium-51 ethylene diamine tetra-acetic acid (51Cr-EDTA) total plasma clearance was evaluated using a multi-sample method (i.e. 12 blood samples) as the reference compared with several simplified methods which necessitated only one or few blood samples. The following 5 methods were evaluated: terminal slope-intercept method with 3 blood samples, simplified method of Bröchner-Mortensen and 3 single-sample methods (Constable, Christensen and Groth, Tauxe). Linear regression analysis was performed. Standard error of estimate, bias and imprecision of different methods were evaluated. For 51Cr-EDTA total plasma clearance greater than 30 ml.min-1, the results which most approximated the reference source were obtained by the Christensen and Groth method at a sampling time of 300 min (inaccuracy of 4.9%). For clearances between 10 and 30 ml.min-1, single-sample methods failed to give reliable results. Terminal slope-intercept and Bröchner-Mortensen methods were better, with inaccuracies of 17.7% and 16.9%, respectively. Although sampling times at 180, 240 and 300 min are time-consuming for patients, 51Cr-EDTA total plasma clearance can be accurately calculated for values greater than 10 ml.min-1 using the Bröchner-Mortensen method. In patients with clearance greater than 30 ml.min-1, single-sample techniques provide a good alternative to the multi-sample method; the choice of the method to be used depends on the degree of accuracy required.
Picciotto
G
G
Servizio di Medicina Nucleare Ospedaliera, Molinette Hospital, Torino, Italy.
Cacace
G
G
Cesana
P
P
Mosso
R
R
Ropolo
R
R
De Filippi
P G
PG
D000328:Adult; D002860:Chromium Radioisotopes; D004492:Edetic Acid / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D008722:Methods; D008875:Middle Aged
D002860:Chromium Radioisotopes; D004492:Edetic Acid