Estimation of Absolute Blood Volume Using Online Dialysate Dilution: When and How to Measure?

Absolute blood volume can be calculated from the increase in relative blood volume after an infusion of a well-defined volume bolus of ultrapure dialysate into the extracorporeal circulation. Several working groups have applied this method in research and clinical practice. A critical analysis of differing blood volume data between working groups revealed methodologic problems of the measurement procedure and some important technical aspects. This paper presents a statement to standardize the method.