EFFECT OF A SLIDING SCALE PROTOCOL FOR HEPARIN ON THE ABILITY TO MAINTAIN WHOLE-BLOOD ACTIVATED PARTIAL THROMBOPLASTIN TIMES WITHIN A DESIRED RANGE IN HEMODIALYSIS-PATIENTS

A prospective, randomized and open study was conducted to evaluate the ability of an individualized heparin dosing protocol to achieve and m aintain whole blood activated partial thromboplastin times (WBAPPT) wi thin a predetermined range in hemodialysis patients. Thirty-one hemodi alysis outpatients who received a total of 99 dialyses were studied. S ystemic heparinization was achieved with a loading dose and a continuo us infusion. WBAPPT, used as a monitoring parameter for heparin therap y, was measured at 5 minutes and 1, 2, 3 and 3 1/2 hours after the sta rt of heparinization. An initial heparin loading dose of 50 u/kg dry w eight was used, with a continuous infusion of 15 u/kg/h and a sliding scale to adjust infusion rates to target WBAPPT in the goal range of 1 50-190 seconds. Individual heparin loading doses for subsequent treatm ent sessions were titrated to achieve the lowest dose which would stil l result in clear dialyzers at the end of hemodialysis. There was a hi gh degree of interindividual variability in heparin requirements. A lo ading dose of 20-25 u/kg placed the majority (72.4%) of the patients w ithin the 150-190 seconds range at the 5 min WBAPPT measurement. The s liding scale method was effective in keeping about 60% of the WBAPPT w ithin the desired range throughout the rest of the hemodialysis sessio n. As the loading or total doses were increased, the incidence of clea r dialyzers increased. In conclusion, this heparin protocol is effecti ve for individualizing heparin doses to achieve therapeutic WBAPPT in hemodialysis patients.