Kt/V and hemodialysis morbidity revisited

Analysis of the National Cooperative Dialysis Study (NCDS) showed that dialysis morbidity was related to Kt/V. Recently, various formulae have been shown to be accurate for easier calculation of Kt/V. We calculated Kt/V in an outpatient unit utilizing Kt/V = -In (R - 0.03 - UF/W) in 51 patients. Kt/V was less than 0.8 in 16 patients (Group A), 0.8-1.0 in 20 (Group B), and greater than 1.0 in 15 (Group C). There was no difference in hematocrit (Hct), BUN, creatinine, serum phosphorus, and albumin. Ratio of men to women was 11/5, 15/5, and 4/11; mean age was 54, 63, and 58 years; mean body weight 177, 144, and 122 lb in Groups A, B, and C, respectively. Dialysis-related hospital admissions were similar (p greater than 0.05). These data suggest patients with higher body weights, and men, frequently had a Kt/V less than 0.8. Kt/V that did not influence biochemical parameters or hospitalizations in this population. This indicates that Kt/V may not be a good predictor of morbidity, and/or some heavier patients may do fairly well even with a Kt/V less than 0.8. The search for a better index of dialysis adequacy should be continued.