Venous Thromboembolism Prophylaxis

Original Date: 07/2025

Recommendations for VTE Prophylaxis:

  • For trauma patients, provide low-molecular weight heparin (LMWH) or unfractionated heparin (UH) and mechanical prophylaxis, preferably with intermittent pneumatic compression (IPC), unless contraindicated.
  • For major trauma patients in whom LMWH and UH are contraindicated, mechanical prophylaxis, preferably with IPC, over no prophylaxis when not contraindicated by lower-extremity injury. Adding pharmacologic prophylaxis with either LMWH or UH when the risk of bleeding diminishes or the contraindication to heparin resolves.

VTE Prophylaxis Drug Dosing:

Enoxaparin
Patient Weight Renal Function Drug Dosing
< 45 kg Crcl > 30 mL/min enoxaparin 20 mg subcutaneous q12 hours
45-89 kg enoxaparin 30 mg subcutaneous q12 hours
90-129 kg enoxaparin 40 mg subcutaneous q12 hours
≥ 130 kg enoxaparin 50 mg subcutaneous q12 hours
Unfractionated Heparin
Patient Weight Renal Function Drug Dosing
< 90 kg Crcl < 30 mL/min heparin 5,000 mg subcutaneous q8 hours
≥ 90 kg heparin 7,500 mg subcutaneous q8 hours

Timing of VTE Chemoprophylaxis:

  • Dosing Schedule
    • Enoxaparin: administer at 0900 and 2100 schedule
    • Heparin: administer at 0600, 1400, and 2200 schedule
      • Nine & Nine is Enoxaparin time! 9:00 and 21:00
      Six, Two, and Ten for the Heparin Win! 6:00, 14:00, 22:00
  • To avoid missed doses, initiate VTE prophylaxis at the earliest time based on the above schedule.
    • Example: Patient arrives in trauma bat at 0600 – start enoxaparin at 0900 after excluding traumatic brain or spine injury requiring emergency operative intervention.

Contraindications to the Immediate Initiation of VTE Chemoprophylaxis:

  • Solid organ injury:
    • Non-operative management of spleen, liver, and kidney injuries (ALL grades)
      • Start VTE prophylaxis within 24 hours of hospital arrival, using the above administration schedule (at the first 0900/2100 following exclusion of TBI or spine injury requiring emergency operation)
      • Patient may still be in emergency department at time of prophylaxis administration.
    • If a patient undergoes angiography or operative repair of a solid organ injury, that injury is considered resolved and VTE chemoprophylaxis can begin immediately if:
      • The angiography shows no extravasation/pseudoaneurysm
      • The extravasation/pseudoanuerysm is successfully embolized
      • The bleeding is controlled surgically
    • VTE chemoprophylaxis should be held for patients with bleeding controlled by temporary measures (e.g. surgical packing) until transfusion requirements abate and coagulopathy resolves (ideally, within 24 hours)
  • Traumatic brain injury:
    • VTE prophylaxis to begin 24 hours after admission (BIG 1 and 2 patients)
    • VTE prophylaxis to begin 24 hours after stable CT Head (BIG 2 and 3 patients)
    • VTE prophylaxis to begin 24 hours after craniotomy
    • Chemoprophylaxis does not need to be held for EVD or ICP placement or removal.
  • Spine fractures and spinal cord injuries:
    • Final spine disposition should occur within 6 hours from consult
      • Will include operative versus non-operative plan and time of operation
    • Non-operative spine injury patients
      • Begin VTE prophylaxis unless other contradiction present
      • If epidural/subdural hematoma present on MRI, begin VTE chemoprophylaxis 24 hours after admission
    • Operative spine injury patients
      • Only hold the dose that would be given in the operating room.
    • After discharge, spinal cord injury patients or spine fractures patients that are immobile should continue VTE chemoprophylaxis with 81 mg aspirin BID for 12 weeks post operatively.
    • Exceptions to this protocol will exist and should be communicated between attending physicians.
  • VTE chemoprophylaxis in trauma patients is NOT routinely held in the following circumstances:
    • Interventional radiology procedures
    • Orthopedic operations (except spine cases)
    • Any other operating room case not discussed above.