[A kinetic model for heparin dosing in patients on chronic hemodialysis]

The quality of anticoagulation was evaluated in 5 patients receiving heparin during chronic hemodialysis. 50 kinetic studies were performed using 2 monitoring tests, TTPK and TCK. Basal and intradialysis measurements were used to estimate sensitivity and the elimination constant according to formulae described by Milthorpe. Mean basal TTPK time was 27.3 sec and TCK time was 211 sec. Mean initial intradialysis TTPK time was 107.5 sec and after correction applying the kinetic model it was 62 sec. Intradialysis TCK time varied from 806 to 683 sec after correction. At the end of the study, mean intradialysis TTPK time was 61 sec not significantly different from the target time of 55 sec. TCK time, however, was significantly greater than target (684 vs 434 sec).