A comparison of methods for the measurement of hemodialysis access recirculation and access blood flow rate

Abstract

Three methods for the measurement of hemodialysis access recirculation (AR) and access blood flow (Qa) rate were compared. These methods are ultrasound dilution (Transonic Hemodialysis Monitor), hematocrit dilution (Crit-Line Monitor), and differential conductivity (Hemodynamic Monitor). Patients were cannulated in a standard fashion and dialysis commenced with lines in normal configuration. Results indicate that ultrasonic dilution and differential conductivity are equal in terms of accuracy and repeatability of measurements. Results from hematocrit dilution correlated well, but tended to underestimate AR and overestimate Qa, and was less reproducible.