Evaluation of intravenous unfractionated heparin dosing protocol for treatment of venous thromboembolism without maximum caps for bolus doses

Abstract

Specific Aims: To determine if a weight-based unfractionated heparin (UFH) dosing regimen without a maximum cap in bolus, in patients with a BMI ? 25 is associated with shorter time to reach therapeutic levels and continue to reach supratherapeutic levels. Subjects: Adults hospitalized at one of three Banner University Medical Center hospitals for greater than 24 hours receiving weight based UFH for venous thromboembolism treatment. Methods: Data extracted from patient charts admitted from October 1, 2017 - December 31, 2018 were inputted into a secure electronic data collection program, Redcap. The data collected included demographics, UFH dosing, and anti-Xa levels. Main Results: The data collected included 200 patients (56% males; mean age = 61.52; SD = 15.66), with 67 (34%) in Group 1 with a BMI ? 24.9 and 133 (66%) in Group 2 with a BMI ? 25. Overall, the mean time to achieve an initial therapeutic anti-Xa level was found to not be significantly different between groups (p = 0.24). The mean percentage of patients in each group who had sustained therapeutic levels were n = 50 (74.63%) in Group 1 and n = 100 (75.19%) in Group 2 was also not significantly different (p = 1.00), but supratherapeutic levels were reached significantly more often in the higher BMI group (group 1 n = 67; group 2 n = 133; p = 0.03). Conclusions: A weight based UFH dosing regimen without a maximum cap in bolus appears to have no difference in time to reach an initial therapeutic anti-Xa level or sustained levels, but supratherapeutic levels occurred more often in those with a BMI ? 25.