title: Mannitol clearance for the determination of glomerular filtration rate-a validation against clearance of51Cr-EDTA.
abstract: We studied the agreement between plasma clearance of mannitol and the reference method, plasma clearance of51Cr-EDTA in outpatients with normal to moderately impaired renal function. Forty-one patients with a serum creatinine <200 μmol l-1entered the study.51Cr-EDTA clearance was measured with the standard bolus injection technique and glomerular filtration rate (GFR) was calculated by the single-sample method described by Jacobsson. Mannitol, 0·25 g kg-1body weight (150 mg ml-1), was infused for 4-14 min and blood samples taken at 1-, 2-, 3- and 4-h (n = 24) or 2-, 3-, 3·5- and 4-h after infusion (n = 17). Mannitol in serum was measured by an enzymatic method. Plasma clearance for mannitol and its apparent volume of distribution (Vd) were calculated according to Brøchner-Mortensen. Mean plasma clearance (±SD) for51Cr-EDTA was 59·7 ± 18·8 ml min-1. The mean plasma clearance for mannitol ranged between 57·0 ± 20·1 and 61·1 ± 16·7 ml min-1and Vd was 21·3 ± 6·2% per kg b.w. The between-method bias ranged between -0·23 and 2·73 ml min-1, the percentage error between 26·7 and 39·5% and the limits of agreement between -14·3/17·2 and -25·3/19·9 ml min-1. The best agreement was seen when three- or four-sample measurements of plasma mannitol were obtained and when sampling started 60 min after injection. Furthermore, accuracy of plasma clearance determinations was 88-96% (P30) and 41-63% (P10) and was highest when three- or four-sample measurements of plasma mannitol were obtained, including the first hour after the bolus dose. We conclude that there is a good agreement between plasma clearances of mannitol and51Cr-EDTA for the assessment of GFR.
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, Institute of Clinical Sciences, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden.
authors.forename: Katalin
authors.initials: K
authors.lastname: Kiss
authors.affiliation: Faculty of Medicine, Institute of Pathophysiology, Semmelweis University, Budapest, Hungary.
authors.forename: Miklós
authors.initials: M
authors.lastname: Molnár
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, Institute of Clinical Sciences, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden.
authors.forename: Sören
authors.initials: S
authors.lastname: Söndergaard
authors.affiliation: Faculty of Medicine, Institute of Internal Medicine, Semmelweis University, Budapest, Hungary.
authors.forename: Gyula
authors.initials: G
authors.lastname: Molnár
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, Institute of Clinical Sciences, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden.
authors.forename: Sven-Erik
authors.initials: SE
authors.lastname: Ricksten
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002860:Chromium Radioisotopes / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics; D003404:Creatinine / Q000097:blood; D004492:Edetic Acid / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007262:Infusions, Intravenous; D007668:Kidney / Q000503:physiopathology*; D007674:Kidney Diseases / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D008353:Mannitol / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics; D008875:Middle Aged; D008954:Models, Biological; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics; D015203:Reproducibility of Results
chemical_list: D002860:Chromium Radioisotopes; D019275:Radiopharmaceuticals; D008353:Mannitol; D004492:Edetic Acid; D003404:Creatinine
keywords: 51Cr-EDTA; glomerular filtration rate; mannitol; plasma clearance; volume of distribution