Enoxaparin Metabolism in Reconstructive Surgery Patients

Summary

Venous thromboembolism (VTE) is a leading cause of death among hospitalized patients, and is an important patient safety issue in plastic surgery. Previous work has shown that enoxaparin prophylaxis can prevent many post-operative VTE events, and current American Society of Plastic Surgeons guidelines support enoxaparin prophylaxis for high-risk patients. Highest risk patients often have cancer or trauma reconstruction. Primary outcomes include 1) peak and trough steady-state aFXa levels in response to standard and escalated doses of enoxaparin and 2) the proportion of patients with appropriate aFXa levels pre and post initiation of a clinical protocol for enoxaparin dose adjustment. The investigators expect that standard dosing will result in inadequate aFXa peak and trough levels, and that the clinical dose adjustment protocol will significantly improve the proportion of in-range aFXa levels. The investigators will also develop a linear regression-based equation to calculate, based on patient-level factors, the required dose of enoxaparin to generate in-range aFXa levels. This research may show that the current "one size fits all" approach to enoxaparin prophylaxis is insufficient. In the trauma and orthopaedic populations, patients with low initial aFXa levels are significantly more likely to develop deep venous thrombosis. Thus, this study has important implications for appropriate enoxaparin dose magnitude and frequency, and may ultimately help to decrease the substantial morbidity and mortality associated with post-operative VTE.

Timeline

Start

2015-03

Primary completion

2016-03

Completion

2016-06

Publications

• Paolini G, Firmani G, Sorotos M, Ninkovic M, Santanelli di Pompeo F. European guidelines on peri-operative venous thromboembolism prophylaxis: first update.: Chapter 8: Plastic surgery. Eur J Anaesthesiol. 2024 Aug 1;41(8):598-603. doi: 10.1097/EJA.0000000000001998. Epub 2024 Jul 10. No abstract available.
• Pannucci CJ, Fleming KI, Varghese TK Jr, Stringham J, Huang LC, Pickron TB, Prazak AM, Bertolaccini C, Momeni A. Low Anti-Factor Xa Level Predicts 90-Day Symptomatic Venous Thromboembolism in Surgical Patients Receiving Enoxaparin Prophylaxis: A Pooled Analysis of Eight Clinical Trials. Ann Surg. 2022 Dec 1;276(6):e682-e690. doi: 10.1097/SLA.0000000000004589. Epub 2020 Oct 19.
• Pannucci CJ, Fleming KI, Agarwal J, Rockwell WB, Prazak AM, Momeni A. The Impact of Once- versus Twice-Daily Enoxaparin Prophylaxis on Risk for Venous Thromboembolism and Clinically Relevant Bleeding. Plast Reconstr Surg. 2018 Jul;142(1):239-249. doi: 10.1097/PRS.0000000000004517.
• Pannucci CJ, Fleming KI. Comparison of face-to-face interaction and the electronic medical record for venous thromboembolism risk stratification using the 2005 Caprini score. J Vasc Surg Venous Lymphat Disord. 2018 May;6(3):304-311. doi: 10.1016/j.jvsv.2017.10.016. Epub 2018 Feb 13.

Drugs

Indications