title: Evaluation of a new method for measuring vascular access recirculation.
abstract: Together with Nikkiso in Shizuoka, Japan, we developed a new method for measuring the rate of vascular access recirculation by the blood volume monitor. This measurement is performed via a method of dilution that employs a marker produced by rapid ultrafiltration using a dialysis machine. In this paper, we evaluate the reliability and safety of this machine, in vitro and in vivo. The safety of this method was evaluated by investigating hemolysis after rapid ultrafiltration. The measurement of free hemoglobin, potassium and haptoglobin in the circulating blood were performed before and after rapid ultrafiltration. No data was found to indicate hemolysis in vivo, detected by an increase in potassium or a decrease in haptoglobin. Evaluation of reliability in an experimental system was also performed on an in vitro recirculation system at a rate of 0, 10, 25, 50, and 70%. Almost all of the measured rates were within ± 10% of the theoretical rate. We performed 20 hemodialysis experiments with vascular access recirculation applying this monitor and simultaneous urea and creatinine dilution methods, which were the recommended standard measurements for vascular recirculation. In 53 measurements of standard vascular shunts with no postural change, differences of the results between the monitor and both dilution methods were only 4.0% and 3.2%, respectively. Regression analysis showed a significant and positive correlation between them (P < 0.0001). We conclude that this new method for measuring vascular access recirculation is applicable in terms of both accuracy and ease of operation.
authors.affiliation: Division of Nephrology, Department of Integrated Medicine, Saitama Medical Center, Jichi Medical University, Saitama, Japan.
authors.forename: Izumi
authors.initials: I
authors.lastname: Yoshida
authors.forename: Susumu
authors.initials: S
authors.lastname: Ookawara
authors.forename: Katsunobu
authors.initials: K
authors.lastname: Ando
authors.forename: Takayuki
authors.initials: T
authors.lastname: Uchida
authors.forename: Atsushi
authors.initials: A
authors.lastname: Horiguchi
authors.forename: Itsuro
authors.initials: I
authors.lastname: Nakajima
authors.forename: Takanori
authors.initials: T
authors.lastname: Komada
authors.forename: Honami
authors.initials: H
authors.lastname: Mori
authors.forename: Kaoru
authors.initials: K
authors.lastname: Tabei
mesh_terms: D001775:Blood Circulation; D001811:Blood Volume Determination / Q000009:adverse effects / Q000379:methods*; D003404:Creatinine / Q000378:metabolism; D005260:Female; D006242:Haptoglobins / Q000378:metabolism; D017583:Hemodiafiltration / Q000379:methods*; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007201:Indicator Dilution Techniques; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000097:blood; D012044:Regression Analysis; D006435:Renal Dialysis / Q000379:methods*; D015203:Reproducibility of Results; D014508:Urea / Q000378:metabolism
chemical_list: D006242:Haptoglobins; D006454:Hemoglobins; D014508:Urea; D003404:Creatinine; D011188:Potassium