STANDARDIZED HEMODIALYSIS PRESCRIPTIONS PROMOTE INADEQUATE TREATMENT IN PATIENTS WITH LARGE BODY-MASS

Background: Although a relation between the adequacy of hemodialysis a nd mortality has been established, hemodialysis prescription is rarely individualized precisely in adults with end-stage renal disease in th e United States. Objective: To test whether persons who receive standa rdized hemodialysis prescriptions have an increased risk for inadequat e hemodialysis with increasing body mass. Design: Cross-sectional stud y. Setting: Four ambulatory hemodialysis facilities in Brooklyn, New Y ork. Patients: 214 patients receiving hemodialysis. Patients were sort ed by body weight into quartiles (groups 1 through 4, in ascending ord er). Measurements: Urea reduction ratio (percentage reduction in blood urea nitrogen concentration after a hemodialysis session), prescribed length of hemodialysis, and body weight quartile at the start of the study. Urea reduction ratio was measured at the start of the study and at weeks 4, 8, and 12, and a mean value was calculated for each patie nt. Inadequate hemodialysis was defined by a urea reduction ratio of 6 5% or less. Results: Women had a higher mean urea reduction ratio (72% +/- 6%)than men (67.6% +/- 7%) (P < 0.001). The urea reduction ratio was inversely related to body weight (r = -0.47; P = 0.001). It was gr eater in group 1 (74% +/- 5.2%) than in group 2 (70% +/- 5.7%), group 3 (68% +/- 5.8%), or group 4 (66% +/- 8.4%) (P < 0.05). Logistic regre ssion done with a urea reduction ratio of 65% or less as the outcome V ariable showed that the odds of receiving inadequate hemodialysis were increased 3.5-fold in men(95% CI, 1.53-fold to 8-fold; P = 0.003), 10 -fold in group 3 (CI, 2.1-fold to 50.3-fold; P = 0.003), and 13-fold i n group 4 (CI, 2.6-fold to 61.6-fold; P = 0.001). Conclusions: Standar dized hemodialysis prescriptions result in inadequate hemodialysis in many patients who weigh more than 68.2 kg.