Continuous infusions of unfractionated heparin (UFH) are still commonly used in the initial treatment of venous thromboembolism (VTE). As a result of UFH's high‐risk profile and common usage, weight‐based UFH nomograms were developed more than 2 decades ago to standardize its dosing. Since that time, there has been scant literature on improving UFH administration. A multidisciplinary team designed an intervention to improve the quality and safety of continuous UFH infusions in hospitalized patients. The aims were to reduce the time to initial therapeutic aPTT values and to increase the overall time patients spent in therapeutic range without increasing time supratherapeutic.


The intervention involved 4 core changes to our existing UFH administration practices: (1) establish a dedicated UFH order set for treatment of VTE incorporating boluses and dosage adjustments, (2) built‐in online weight‐based dosing calculator, (3) new aPTT(AC) that prompts a priority lab draw and lab processing, and (4) nursing dual sign‐off on dosage adjustments To determine baseline performance and measure the impact of our intervention, we extracted data from our electronic medical record on adult patients who were on continuous‐infusion UFH for VTE from January 2010 through October 2012. Patients on therapy for <24 hours and patients with less than 2 PTT values were excluded from the analysis. After exclusions were applied, 4819 patients in the preintervention group and 4524 patients in the postintervention group were analyzed.


Postintervention, the proportion of patients who were therapeutic within 24 hours increased 15.5% (69.7%–79.5%, P < 0.0001) and median time to therapeutic aPTT decreased by 15.8% (13.3–11.2 hours, P < 0.0001; Fig. 1). In addition, postintervention, the proportion of time spent inside the therapeutic range increased from 42.1% to 47.6% (P < 0.0001). There was no difference in percentage of time supratherapeutic between the 2 groups. Safety analysis revealed no statistical difference in rates of major bleeding with the new UFH nomogram upgrade.


This safety initiative demonstrates a significant improvement in the safe and effective use of continuous UFH infusion in the treatment of VTE. Through creative utilization of technology and improved process of care we have brought high reliability to this high‐risk medication. To our knowledge, this is the largest cohort of patients evaluated for safe VTE treatment with a UFH nomogram. Although our evaluation looked at a single center, these interventions could be implemented in other hospital systems with EHR and CPOE capabilities.

Figure 1.Kaplan–Meier failure plot showing proportion of patients achieving therapeutic aPTT value over time in hours.