Heparin elimination and hemostasis in hemodialysis

The heparin concentrations at the end of dialysis and the post-dialysis hemostasis were studied in 16 patients in a chronic hemodialysis program. In 8 of the patients, the heparin half-life values after dialysis were determined as well. The heparin doses were calculated as 90 IU/kg body-weight, administered in a standardized way. The heparin concentrations and the half-life values varied between 0.12-0.94 IU/ml and 29-114 minutes respectively, indicating that the heparin administration must be individually modelled. The hemostasis, measured by the arterial pressure times, was positively correlated to the heparin concentrations. Heparin levels less than 0.3 IU/ml were regularly associated with pressure times less than 10 minutes and no remaining heparin activity two hours after dialysis. In order to minimize the risk of both bleeding and clotting complications at the end of and after dialysis, a heparin concentration of approximately 0.25 IU/ml should be aimed for.