P. Prandoni et al., USE OF AN ALGORITHM FOR ADMINISTERING SUBCUTANEOUS HEPARIN IN THE TREATMENT OF DEEP VENOUS THROMBOSIS, Annals of internal medicine, 129(4), 1998, pp. 299-302
Background: Despite the widespread use of subcutaneous heparin in the
initial treatment of deep venous thrombosis, there are no guidelines f
or achieving adequate anticoagulation with this drug. Objective: To im
plement a weight-based algorithm for the administration of subcutaneou
s unfractionated heparin after an intravenous loading dose. Design: Pr
ospective cohort study. Setting: University hospital. Participants: 70
outpatients with proximal venous thrombosis. Intervention: An intrave
nous bolus of heparin followed by a subcutaneous injection of heparin
in doses adjusted for body weight. Subsequent adjustments of the subcu
taneous heparin dose were scheduled twice daily according to the algor
ithm; the activated partial thromboplastin time (aPTT) was measured in
the mid-interval (target range, 50 to 90 seconds). Results: The thera
peutic threshold aPTT (greater than or equal to 50 seconds) was achiev
ed in 61 patients (87%) within 24 hours and in 69 patients (99%) withi
n 48 hours. In 7 patients (10%), a supratherapeutic aPTT lasted more t
han 12 hours. No major bleeding episodes or cases of heparin-induced t
hrombocytopenia were seen. Three patients (4.3% [95% CI, 0.9 % to 12.0
%]) had recurrent thromboembolism during 3 months of follow-up. Concl
usion: The administration of subcutaneous heparin according to a weigh
t-based algorithm allows the rapid achievement of effective and safe a
nticoagulation in patients with deep venous thrombosis.