Thromboprophylasis in Trauma Pts

Thomas J Moore MD

Richard Thomas MD

Atlanta Trauma Symposium

April 26, 2013

No Conflicts

Introduction

Introduction

• Venous thromboembolic (VTE) disease is associated with significant morbidity and mortality

• Acute PE is responsible for more than 150,000 deaths per year

• Symptomatic PE: 2-10% of pelvic fx pts, fatal 0.5%-2%

• Most preventable cause (3rd most frequent cause) of in-hospital mortality among trauma patients

• Increased risk of developing VTE in patients undergoing major orthopedic procedures involving: – Pelvis – Hip – Knee – Multiple trauma involving lower

extremity fractures – Spinal cord injury Tornetta JAAOS 2012

Pathogenesis of VTE disease • Virchow’s Triad

– Endothelial injury

– Venous stasis

– Hypercoagulable state

• Endothelial injury alone can induce thrombosis

– Examples:

• Kinking of veins during total hip and knee surgery

• Use of a tourniquet

• Limb positioning during surgery

• Poor mobility after surgery leads to stasis, which leads to platelet adhesion to endothelium

• Mechanism by which hypercoagulable state leads to clot formation is poorly understood

Risk Factors • Inherited thrombophilia

• Bed rest or immobility for more than 5 days

• Malignancy

• Estrogen or hormone replacement therapy

• History of MI or stroke

• Obesity

• History of smoking

• Prior VTE

Increased risk of VTE Associated with Inherited Thrombophilia

• The balance between procoagulant and anticoagulant systems disturbed by overactive coagulopathic factors or underactive antithrombotic factors

• ~ 15% of pts <45 yrs with idiopathic DVT’s have deficiency of protein C, protein S or antithrombin III

• Recommend LMWH in asymptomatic pts with known heritary thrombophilia with major trauma

• ? Routine testing for pts with clinically significant DVT with trauma unless family history or recurrent DVT’s

• Factor V Leiden mutation

• Heterozygous………………………………..7X

• Homozygous………………………………….80X

• Prothrombin G20210A………………………..2.8%

• Antithrombin III deficiency…………………..5-20X

• Protein C deficiency………………………………2-10X

• Protein S deficiency……………………………….2-10X

• Hyperhomocysteinemia………………………….2.5X

• Elevated factor VII…………………………………..5X

• Elevated factor XI……………………………..........2.2X

Grabowski JAAOS 2013

Thromboembolic Prophylaxis

99% : VTE prophylaxis necessary

VTE Prophylaxis in Orthopaedic Trauma Patients

• The American College of Chest Physicians (ACCP) and American Academy of Orthopedic Surgeons (AAOS) have designed comprehensive Thromboprophylasis guidelines

• Little recommendations for trauma patients and more specifically orthopaedic trauma patients

American College of Chest Physicians Evidence-based Guidelines for Venous Thromboembolic

Prophylaxis: the Guideline Wars Are Over • ACCP Guidelines (2012) and the AAOS Guidelines (2011) provide safety

and efficacy recommendations for VTE prophylaxis

• For pts undergoing “major orthopaedic surgery”: dual prophylaxis with an antithrombotic agent and an intermittent pneumatic compression device (IPCD) during hospital stay and Thromboprophylasis for up to 35 days as outpatient (up from 10-14 days)

• In pts undergoing “major orthopaedic surgery” and with risk of bleeding: an IPCD or no prophylaxis rather than pharmacologic treatment

• In pts undergoing “major orthopaedic surgery” with contraindications to to both pharmacologic and IPCD prophylasis: no IVC filter

• Moderate-quality evidence to support the use of low-dose ASA for VTE prophylasis compared to no prophylasis

Lieberman JAAOS 2012

HIERARCHY OF EVIDENCE

• Level 1…………………… Randomized Trials

• Level 2……………… Prospective Cohort Studies

• Level 3……………. Case Control Studies

• Level 4…………. Retrospective Case Series

• Level 5………… Expert Opinion

Less Bias

Meta-analysis

Basic Science

Economic Clinical Relevance

Meta-analysis

1. Enoxaprin vs “new” agents (fondaparinux, dabigatran, apixaban, rivaoxabin) : relative equivalence in DVT and PE prophylasis but difference in bleeding complications and cost Ann Vasc Surg 2913

2. LMWH vs “other” anticoagulents (unfractionated heparin, Vit K antagonists, Factor Xa inhibitors, direct thrombin inhibitors): additional benefits with LMWH with less harm Pharmotherapy 2012

3. Pharmacologic agents plus IPCD vs IPCD alone: no difference in DVT or PE rates Pharmacotherapy 2013

Pharmacologic Prophylaxis • Rivaroxaban (Xarelto)

– First oral selective Xa inhibitor

– Approved for DVT prophylaxis in patients undergoing total knee and hip arthroplasty surgery

– Taken once daily

– Relatively low cost

– No monitoring needed

– Shown to reduce the risk of VTEs after total knee and hip surgery

– May be associated with increased wound bleeding complications

Jameson JBJS 2012

• 304 patients with hip and pelvic fractures randomized to SCDs or no treatment

• Followed by Doppler, duplex scans, and VQ scans • 11% incidence of VTE in control group • 0.4% incidence of VTE in experimental group • In patients with hip fracture:

– 12% incidence in control group vs. 4% in experimental group

• No difference in patients with a pelvis fracture

Indications, Complications, and Management of IVC Filters: the Experience of 952 Pts in a

Level 1 Trauma Center

• Only 8.5% filters removed, despite the use of “removeable” filters

• 74 clinically significant venous thrombotic events occurred post filter placement, including 25 PE’s

• “The use IVC filters for prophylasis for VTE in trauma pts results in suboptimal outcomes due to high rates of venous thromboembolism and potential complications” Sarosiek JAMA 2013

Conclusions

Legal and Economic Considerations

1. Geographic variability in use of IVC filters: higher use in states with significantly higher paid malpractice claims per 100K and significantly higher liability insurance premiums (Meltzer Surgery 2013)

2. 2nd highest malpractice payout for fatal PE without prophylasis in 2009 Mag Mutual

3. Pay for Performance criteria in pilot study hip fx’s in California: $ surgical fee penalty for absence of DVT Prophylasis

Inpatient Enoxaparin and Outpatient ASA Chemoprophylaxis Regimen after THR and TKR

• 500 pts

• Inpatient enoxaparin (ave 2.75days) followed by outpatient ASA (28 days)

• VTE rate 0.6% (1 DVT, 2 PE)

• Bleeding (requiring Tx) 1.8%

• Compared favorably with control group Rx’ed with 14 days enoxaparin followed by 14 days ASA

Hamilton, Bradbury, Roberson J Arthroplasty 2012

Recommendations for Thromboprophylasis in Major Trauma

1. Peri-operative: pharmacologic (Lovenox) with IPCD

2. Outpatient Rx: ASA 325mg daily for 28 days

3. If significant risk of bleeding (ie liver contusion, epidural head bleed) no pharmacologic antithrombotic Rx, IPCD if possible

4. No indication for IVC filter placement for prophylaxis

5. No indication for radiographic imaging to r/o DVT at discharge from initial hospitization