Abstract
Parenteral anticoagulation is a cornerstone in the management of venous and arterial
thrombosis. Unfractionated heparin has a wide dose/response relationship, requiring
frequent and troublesome laboratorial follow-up. Because of all these factors, low–molecular-weight
heparin use has been increasing. Inadequate dosage has been pointed out as a potential
problem because the use of subjectively estimated weight instead of real measured
weight is common practice in the emergency department (ED). To evaluate the impact
of inadequate weight estimation on enoxaparin dosage, we investigated the adequacy
of anticoagulation of patients in a tertiary ED where subjective weight estimation
is common practice. We obtained the estimated, informed, and measured weight of 28
patients in need of parenteral anticoagulation. Basal and steady-state (after the
second subcutaneous shot of enoxaparin) anti-Xa activity was obtained as a measure
of adequate anticoagulation. The patients were divided into 2 groups according the
anticoagulation adequacy. From the 28 patients enrolled, 75% (group 1, n = 21) received
at least 0.9 mg/kg per dose BID and 25% (group 2, n = 7) received less than 0.9 mg/kg
per dose BID of enoxaparin. Only 4 (14.3%) of all patients had anti-Xa activity less
than the inferior limit of the therapeutic range (<0.5 UI/mL), all of them from group
2. In conclusion, when weight estimation was used to determine the enoxaparin dosage,
25% of the patients were inadequately anticoagulated (anti-Xa activity <0.5 UI/mL)
during the initial crucial phase of treatment.
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Article Info
Publication History
Published online: April 05, 2010
Accepted:
January 11,
2010
Received in revised form:
January 11,
2010
Received:
November 21,
2009
Footnotes
☆The authors have no disclosure to make.
Identification
Copyright
© 2011 Elsevier Inc. Published by Elsevier Inc. All rights reserved.
