Evaluation of Hemodialysis Adequacy: Correlation between Kt/Vurea and Other Methods

Objective: Uremic toxins must be adequately cleared to reduce mortality and morbidity in chronic hemodialysis patients. The second-generation Daugirdas formula (D) is recommended for measurement of hemodialysis adequacy according to the guidelines specified by Kidney Disease Outcomes Quality Initiative (KDOQI) in guidelines. We aimed to compare the Kt/V ratio obtained by D (D Kt/V) to the urea reduction ratio (URR) and the Online Clearance Monitor (OCM®). Materials and Methods: Our research is across-sectional study on 48 patients who are on maintenance hemodialysis (HD). A total of 1990 HD sessions were performed 3 times a week for 4 hours each day for 3 months. Ionic dialysate was measured by OCM module of the Fresenius 4008 C machine. In the same HD session, URR and Kt/V ratio were calculated using a single-pool Daugirdas formula. Results: This study included 48 (Male: 24, Female: 24) adult chronic HD patients. Mean age of the patients was 54.5±18.1 years (16-81 years). Mean Kt/V value was found be higher when calculated using D formula (1.54±0.36) than what was measured by ionic dialysate (1.37±0.32) (p<0.0001). Comparison between D Kt/V and URR showed a statistically relevant significance (p<0.0001, r=0.92). Mean ultrafiltration (UF) was 1521±1054 milliliters per session. When D Kt/V was calculated without UF, the mean Kt/V value measured by ionic dialysate was not different from D Kt/V without considering UF (1.43±0.32) (p=0.101). In spite of the fact that URR was positively correlated with two formulas, the relationship between D Kt/V and URR was statistically more significant. Conclusion: In our study, Kt/V calculated with D formula was higher than Kt/V measured by OCM. If the Daugirdas formula was calculated without considering UF, the Kt/V found by both methods was similar. Even though the URR correlated with two formulas, the relationship between D Kt/V and URR was statistically more significant. OMC is a practical tool that can help us to assess hemodialysis adequacy. Cite this article as: Baloğlu İ, Selçuk NY, Evran H, Tonbul HZ, Türkmen K. Evaluation of Hemodialysis Adequacy: Correlation between Kt/Vurea and Other Methods. Turk J Nephrol 2019; 28(3): 193-6.