Improved dialyzer reuse after use of a population pharmacodynamic model todetermine heparin doses

Anticoagulation with heparin is performed to prevent clotting during dialys is, However, heparin doses are usually determined empirically, and dialyzer clotting is a common reason for discarding reused dialyzers, We hypothesiz ed that using a population pharmacodynamic model to determine individual he parin doses would improve dialyzer reuse rates. A previously published mode l was used to determine the loading dose and infusion rate of heparin neede d to increase the intradialytic whole-blood clotting time to 150% of the pr edialysis value. The effectiveness of the model was assessed by comparing d ialyzer reuse rates and delivered Kt/V-urea before and after implementation of the model in 22 chronic hemodialysis patients. As an additional control , a similar group of 22 patients were followed up during the same period wi thout adjustment of their heparin doses. Implementation of the model result ed in no change in the average loading dose (2,382 +/- 628 versus 2,425 +/- 908 IU; P = not significant) or average infusion rate (1,398 +/- 367 versu s 1,393 +/- 532 IU/h; P = not significant) of heparin, However, individual patients required changes in loading dose or infusion rate. Dialyzer reuse rates increased significantly over time in the treatment group but remained unchanged in the control group (P < 0.003), Kt/V-urea remained unchanged t hroughout the study period in both patient groups, From these data, we conc lude that the use of a heparin model can improve dialyzer reuse rates witho ut compromising the delivered dose of dialysis, (C) 2000 by the National Ki dney Foundation, Inc.