Assessment of haemodialysis adequacy by ionic dialysance: intra-patient variability of delivered treatment

Adequate delivered dose of solute removal (as assessed by urea reduction and calculation of Kt/V) is an important determinant of clinical outcome in chronic haemodialysis (HD) patients. The requirement for multiple blood sampling and efforts taken to minimize the effects of rebound on post-treatment samples ensure Kt/V is measured only intermittently. On-line conductivity monitoring (using sodium flux as a surrogate for urea) allows the repeated non-invasive measurement of Kt/V on each HD treatment. We have studied the accuracy of this method of measuring Kt/V, and the variability of treatment dose delivered to individual patients.