Hemodialysis Adequacy: A Comparative Multicenter Study Between OCM and Calculated Kt/V from Two Centers in the Gulf

Introduction: 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. This requires both prescription of an adequate dose of HD and regular assessment that the delivered treatments are also adequate. On line conductivity monitoring Kt/V OCM online clearance measurement (OCM) (OCM) -using sodium flux as a surrogate for urea- allows the repeated non-invasive measurement of Kt/V on each HD treatment. Methods: We prospectively studied 131 (63 males, 68 females) established chronic HD patients over 8 weeks period (1048 treatments). A pre and post dialyzer measurement of the conductivity is performed by two mutually independent temperature-compensated conductivity cells equipped with Fresenius 4008 S ® dialysis machines. Urea reduction was measured (once a week) by a single pool calculation using immediate post treatment sampling. No changes were made to any of the dialysis prescriptions over the study period. Values of calculated Kt/V (conventional method with Daugirdas’ formula) Kt/V Dau and simultaneously obtained online Kt/V OCM were compared. Results: There was a statistically significant difference between calculated Kt/V DAU and Kt/V OCM over the study period. The mean calculated Kt/V DAU was 1.459 ± 0.31, and mean OCM was 1.139 ± 0.14 (p = 0.000), yet there was moderate correlation between calculated Kt/V DAU and Kt/V OCM (r 2