Evaluation of Hemodialysis Adequacy: Correlation between $Kt/V_{urea}$ and Other Methods

Özet

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 tothe guidelines specified by Kidney Disease Outcomes Quality Initiative (KDOQI) in guidelines. We aimed to compare theKt/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 measuredby 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±18.1years (16-81 years). Mean Kt/V value was found be higher when calculated using D formula (1.54±0.36) than what wasmeasured by ionic dialysate (1.37±0.32) (p<0.0001). Comparison between D Kt/V and URR showed a statistically relevantsignificance (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 DKt/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 formulawas calculated without considering UF, the Kt/V found by both methods was similar. Even though the URR correlated withtwo formulas, the relationship between D Kt/V and URR was statistically more significant. OMC is a practical tool that canhelp us to assess hemodialysis adequacy.