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Published on: October 12, 2012
Achieving target antifactor Xa activity with a heparin protocol based on sex, age, height, and weight
Terry K Rosborough1, Michele F Shepherd
1Medical Education Department, Abbott Northwestern Hospital, Minneapolis, Minnesota 55407, USA.
Study Objectives:
To develop and validate an improved unfractionated heparin (UFH) dosage protocol, using antifactor Xa levels as the outcome variable.
Design:
Prospective case series.
Setting:
A 625-bed, adults-only private, tertiary care teaching hospital.
Patients:
Three hundred seventy-two patients receiving UFH for eight different indications were in the protocol derivation group. One hundred ninety-seven patients were in the final validation group. Intervention. Variables that predicted successful UFH treatment were determined by analysis of variance and regression.
Measurements And Main Results:
Sex, age, height, weight, UFH dosage, and antifactor Xa levels were variables. A regression model using sex, age, height, and weight was superior to a weight-only model in predicting UFH dosage. Target-range antifactor Xa levels were achieved with the new protocol in 122 (87%) of 140 patients within 24 hours of start of therapy.
Conclusion:
A UFH dosage protocol based on patient sex, age, height, and weight produced improved initial target antifactor Xa levels compared with a weight-based protocol. The protocol is computerized and easy to apply.
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