Background: Hemodialysis (HD) dose is well known to highly correlate with the prognosis of HD patients. However, the standard method, Kt/V requires a blood sample and subsequent calculation using a formula containing a natural logarithm, which might be tedious to some extent. Thus, determining the value might be inconvenient in emergency settings. We deduced that the product of body weight-normalized blood flow rate (Qb/BW) and treatment time (Qbt/10BW) could approximately equal single pool Kt/V. In the present study, we validated the deduction by a study of actual HD patients.
Methods: One hundred two HD inpatient at our hospital were studied. We collected the data from the medical records retrospectively. The correlation between Qbt/10BW and Kt/V was examined by simple regression analysis. The factors that affect the errors in estimating Kt/V were also examined by multivariate analysis.
Results: The comparison between Kt/V and Qbt/10BW indicated a close correlation: regression coefficient=1.070 (0.955-1.185), (R²=0.773, p<0.0001). Multivariate analysis showed that the difference between Kt/V and Qbt/10BW is influenced by Qb, post-HD body weight, and gender.
Conclusion: Although confounding factors exist in the estimation of Kt/V obtained by our new method, the present equation is easy to calculate and is useful especially in emergency settings or for the prescription of HD.