Enoxaparin Metabolism in Reconstructive Surgery Patients
Condition: Venous Thromboembolism; Deep Venous Thrombosis; Pulmonary Embolus; Reconstructive Surgery
MeSH terms: Pulmonary Embolism; Thrombosis; Thromboembolism; Venous Thromboembolism; Venous Thrombosis
Intervention: Enoxaparin
Intervention description: Enrolled patients will receive real-time monitoring of peak and trough steady state anti-Xa levels. Out-of-range patients will receive real time dose adjustment of Enoxaparin using a clinical protocol developed with our inpatient pharmacists.
Intervention MeSH terms: Enoxaparin
Phase: Phase 2
Study type: Interventional
Primary purpose: Other
Intervention model: Single Group Assignment
Masking: None (Open Label)
Enrollment: 110.0
Sex: All
Minimum age: 18 Years
Healthy volunteers: No

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.
    

Eligibility criteria:

        Inclusion Criteria:

        Inclusion criteria will include:

          -  adult (age ≥18) patients presenting for reconstructive surgery under general
             anesthesia.

          -  expected post-operative stay will be at least three days to allow peak aFXa levels to
             be drawn.

          -  eligible patients will include those having major reconstructive surgery.

        Exclusion Criteria:

        Exclusion criteria will include:

          -  contraindication to use of enoxaparin,

          -  intracranial bleeding/stroke,

          -  hematoma or bleeding disorder,

          -  known heparin-induced thrombocytopenia,

          -  creatinine clearance ≤30mL/min,

          -  serum creatinine >1.6mg/dL, or epidural anesthesia.