Evaluation of an Unfractioned Heparin Pharmacy Dosing Protocol for the Treatment of Venous Thromboembolism in Nonobese, Obese, and Severely Obese Patients

Authors

Chad A. Knoderer, Butler UniversityFollow
Lindsey M. Hosch
Emily Y. Breedlove
Lauren E. Scono

Document Type

Article

Publication Date

Spring 5-16-2017

Publication Title

Annals of Pharmacotherapy

DOI

http://dx.doi.org/10.1177/1060028017709819

Abstract

Background: Despite large interpatient variability in dose response, heparin is utilized for treatment of venous thromboembolism (VTE). Current data on the optimal heparin dosing in obese patients are conflicting. Objective: The objective was to evaluate the time and dose required to achieve a therapeutic activated partial thromboplastin time (aPTT) in nonobese, obese, and severely obese patients using a pharmacist-directed heparin dosing protocol. Methods: This was a retrospective cohort study in a single-center community hospital inpatient setting. Adult patients receiving heparin for VTE treatment from July 1, 2013, to July 31, 2015, were evaluated. Patients were categorized into 3 groups: nonobese (BMI < 30 kg/m²), obese (BMI = 30-39.9 kg/m²), and severely obese (BMI ≥ 40 kg/m²). Data on height, weight, initial bolus dose, initial infusion rate, time to therapeutic aPTT, and therapeutic infusion rate were collected. Dosing body weight (DBW) was utilized for patients 20% over their ideal body weight (IBW). The primary outcome was time to therapeutic aPTT. Results: Analysis included 298 patients. Median times to therapeutic aPTT (hours:minutes) in the nonobese, obese, and severely obese were 15:00 (interquartile range [IQR] = 8:05-23:21), 15:40 (IQR = 9:22-25:10), and 15:22 (IQR = 7.54-23:40), respectively (P = 0.506). There was no difference in bleeding among the nonobese (14%), obese (13.9%), or severely obese groups (7.9%; P = 0.453). No adverse thrombotic events occurred during hospitalization. Conclusion: Using a DBW for heparin dosing in patients 20% over their IBW resulted in similar times to therapeutic aPTT and adverse events in the nonobese, obese, and severely obese.

Rights

This is a post-print version of an article originally published in Annals of Pharmacotherapy,2017, Volume 51, Issue5.

The version of record is available through: SAGE.

Recommended Citation

Knoderer, Chad A.; Hosch, Lindsey M.; Breedlove, Emily Y.; and Scono, Lauren E., "Evaluation of an Unfractioned Heparin Pharmacy Dosing Protocol for the Treatment of Venous Thromboembolism in Nonobese, Obese, and Severely Obese Patients" (2017). Scholarship and Professional Work – COPHS. 241.
https://digitalcommons.butler.edu/cophs_papers/241