Comparison of the efficacy of the weight-based heparin dosing nomogram and standard method.

ABSTRACT

Nowadays, heparin is extensively used in patients with various medical diseases without standardized dose adjustment. Previous studies revealed that delayed therapeutic level achievement led to suboptimal outcome. Objective: To determine the most effective method of heparin dose adjustment and factors affecting appropriate heparin dose. Methods: All patients requiring heparin treatment were monitored for APTT ratio in phase 1 (conventional method), then randomized into Standard and Weight-based method in phase 2 with the same manner of APTT ratio monitoring. Results: Student t-test for primary outcome favored the Standard dosing heparin nomogram in comparison with conventional method at 18 h ( p-value = .0006) and 24 h ( p-value = .03) and the Weight-based nomogram at 18 h ( p-value = .02). At 24 h, 21 of 28 patients ( 75%) of the Standard nomogram group achieved the therapeutic range, comparing with 14 of 28 patients (50%) in the Weight-based nomogram group and 15 of 39 patients ( 38%) in conventional group. Only age and body weight may affect the appropriate heparin dose. Conclusion: The Standard heparin nomogram was more effective and practical in heparin dose adjustment. Factors affecting appropriate heparin dose were age and body weight.