AC FORUM 2025

Presentation Details

SPLTRAK Abstract Submission

Analysis of Xa levels and PTTs during the first 48 hours of anticoagulation with unfractionated heparin infusion

Kaitlyn Loi
Community Regional Medical Center, Fresno, CA, United States

Introduction
For acute venous thromboembolism (VTE), the CHEST guidelines recommend a PTT goal of 1.5 to 2.5 times the control or anti-factor Xa level of 0.3 - 0.7 units/mL. In 2021, our institution added nurse driven Xa nomograms to titrate heparin infusion. The objective of this study is to determine the proportion of patients on heparin infusion for VTE that achieved therapeutic Xa level or PTT within the first 48 hours of initiating heparin infusion.
Methods
This was an IRB-exempt, retrospective analysis of inpatient orders for heparin infusion at a community-based academic teaching hospital. Inclusion criteria were adult patients ordered for heparin infusion for the indication of VTE who received heparin infusion for at least 4 days. Xa levels and PTTs during the first 48 hours of initiating heparin infusion were collected and analyzed.
Results
A total of 40 patients were included. For patients receiving Xa monitoring with boluses, the proportions of patients in therapeutic range were 10% at 6 hours, 70% at 12 hours, 40% at 18 hours, 40% at 24 hours, 50% at 30 hours, 40% at 36 hours, 90% at 42 hours, and 60% at 48 hours. For patients receiving PTT monitoring with boluses, the proportions of patients in therapeutic range were 10% at 6 hours, 20% at 12 hours, 30% at 18 hours, 40% at 24 hours, 50% at 30 hours, 40% at 36 hours, 30% at 42 hours, and 60% at 48 hours.
Conclusion
The majority of patients on PTT monitoring spend most of their first 48 hours on heparin infusion outside of therapeutic range. One hundred percent of patients on Xa monitoring achieve therapeutic Xa for at least one reading by the 24-hour mark after initiating heparin infusion. No patient had all therapeutic values. Fifty percent of patients receiving PTT monitoring with boluses never had a therapeutic PTT within the first 48 hours on heparin infusion.