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VTE Prophylaxis

Division of Acute Care Surgery
Revised: January 2025

I. Purpose

Prevent pulmonary embolism (PE) and deep vein thrombosis (DVT) in trauma patients.

II. Risk Factors

High Risk
- Age > 60
- GCS < 9 > 4 hrs
- PMH of VTE
- Lower extremity fracture
- Multiple spinal fractures
- Pregnancy

Very High Risk
- SCI with paralysis
- ≥2 complex lower extremity fractures
- Major pelvic fracture
- ≥3 long bone fractures (≥1 in LE)
- Age ≥ 75 + any high-risk factor
- Abdominal/LE venous repair/ligation

III. VTE Prophylaxis Protocol

A. All Trauma Patients

  • Apply bilateral SCDs unless contraindicated

B. Enoxaparin Dosing (q12h)

Weight (kg) Dose Anti-Xa Required
< 50 30 mg Yes
50–89 30 mg No
90–129 40 mg Yes
130–179 60 mg Yes
≥ 180 80 mg Yes

C. Other Considerations

  • BMI ≥ 40 → SQ heparin 7500 units q8h if no epidural or block
  • Do not hold for elevated INR due to liver dysfunction
  • Hold only for spine/neurosurgical OR or if attending requests

IV. Exceptions

A. TBI – Based on Brain Injury Guidelines (BIG)

BIG Category Description Start VTE ppx
BIG 1 Minor bleeds, stable repeat CTH 24 hrs
BIG 2 Moderate bleeds 48 hrs
BIG 3 Severe bleeds, worsening on repeat CTH 72 hrs
  • MMA embolization → hold morning of procedure
  • Intraspinal hematoma → start within 48 hrs
  • Spine surgery → hold AM of surgery, resume 24 hrs post-op
  • Enoxaparin preferred with ICP monitor/EVD

V. Epidural/Block/Lumbar Drain

  • Hold enoxaparin 12 hrs pre-placement and 4 hrs post-removal
  • Use heparin 5000 units q8h + SCDs while catheter is in place

VI. Renal Impairment

  • CrCl < 30 or significant ↑ in SCr → use SQ heparin
  • RRT → heparin preferred

VII. Anti-Xa Monitoring

  • Indications: weight <50 or ≥90 kg; all very high-risk patients
  • Draw peak 4 hrs after 3rd enoxaparin dose
  • Goal: 0.2–0.4 IU/mL

Dose adjustment:

  • Below goal → ↑ to next syringe size
  • Above goal:
  • ↓ to next size or 30–40 mg q24h
  • If still high → switch to heparin q8h
  • Non-standard doses → monitor Anti-Xa weekly
  • If at goal on weight-based dosing → no further monitoring

VIII. Surveillance

  • Very high-risk: Duplex LE US 72 hrs post-admission, then weekly × 4 weeks
  • Then every 2 weeks thereafter

IX. IVC Filter

Refer to IVC Filter PMG

Consider prophylactic filter if:

  • SCI with paralysis
  • IVC/iliac/femoral repair or ligation
  • Severe pelvic + LE long bone fracture
  • AIS head ≥3 + anticoagulation contraindication
  • Anticoag failure or complication

X. Post-Discharge VTE Prophylaxis

A. 30 Days:

  • Very high-risk (e.g. SCI)
  • Operative LE fracture
  • Femoral head fracture
  • Non-ambulatory (>30 ft)

B. 90 Days:

  • Spinal cord injury

XI. References

Essential literature includes EAST PMG (2002), multiple trauma studies validating weight-based enoxaparin dosing, safety in TBI/spine patients, and recent AAST/ACS protocols for post-discharge prophylaxis.
Full citations available upon request.

XII. Authors

  • Bradley Dennis, MD
  • Jill Streams, MD
  • Jennifer Beavers, PharmD, BCPS
  • Jennifer Emerson, PharmD
  • Chelsea Tasaka, PharmD, BCCCP