The determination of Kt/V by ionic dialysance is a technique that has extended its use in hemodialysis clinics. The clinical guidelines have reflected the need to validate this method as a determinant of the dose of dialysis.

Determine in daily practice, the influence of hemodialysis characteristics and medication on Kt/V results by ionic dialysance (Kt/V OCM) and compare them with Kt/V measures by serum urea (Kt/V Daugirdas).

Cross-sectional and observational study. Participants: 127 patients on chronic hemodialysis. Measurements: Descriptive variables, study variables (Kt/VOCM, Kt/VDaugidas), and the variables that modified the effect (patient temperature, serum sodium, vascular access, recirculation, blood flow, hemodialysis technique, dialyzer, acid concentrate, conductivity, dialyzate flow).

The mean of Kt/V Daugirdas was 1.84 and the Kt/VOCM mean 1.65; Pearson's was CC r=0.54; P<0.001 and Lin CCC=0.48. In the linear regression, the variables related to hemodialysis technique showed no statistical association with the measurement obtained by Kt/VOCM. Monosodium phosphate and 20% sodium chloride dispensing were associated with a higher Kt/VOCM.

The different technical aspects noted during HD sessions do not influence Kt/V OCM outcomes. Kt/V determined by ionic dialysance isn’t similar to that determined by serum urea. When assessing dialysis doses measured by dialysance, consider that it is not the same as determined with serum urea, but it provides an approximation to estimate dialysis doses in real time. It is necessary to consider if drugs or supplements have been administered that can modify it when interpreting the results.