VTE Prophylaxis Resident Quick Guide

Scope: Adult trauma/orthopedic admissions (>=15 years). Operational aim: start mechanical + chemoprophylaxis early once hemostasis is secure.

Immediate Admission Actions

• Apply mechanical prophylaxis (SCDs) unless contraindicated.
• Use standard administration windows:
  • Enoxaparin at 09:00 and 21:00.
  • UFH at 06:00, 14:00, and 22:00.
• Start chemoprophylaxis once hemostasis is secure (goal <=24-48h in most patients).
• Reassess holds daily; avoid unexamined prolonged holds.

First-Line Strategy

• LMWH (enoxaparin) weight-based is default.
• UFH if severe renal dysfunction or specific contraindication to LMWH.

Weight-Based Dosing (Current Protocol)

*High-risk reduction applies to BIG 3 TBI, post-craniotomy, or complete SCI (AIS A) during first 72 hours.

Exceptions

• Age >65 or weight <50 kg: start 30 mg q12h.
• CrCl 15-29: LMWH 30 mg daily with anti-Xa preferred over UFH.

Timing by Injury (Use Most Conservative If Multiple Injuries)

• Pelvic/long-bone fracture post-op: <=24h post-op.
• Hip fracture operative: 6-12h post-op.
• Spine surgery instrumented: 24-48h post-op.
• Spine fracture non-op stable: 24-48h.
• SCI (with or without surgery): <=48h.
• TBI BIG 1-2 (stable): <=24h.
• TBI BIG 3/post-craniotomy: 24-72h after stable CT.
• Solid organ NOM grade I-III: <=24h.
• Solid organ NOM grade IV-V: <=48h once hemostasis confirmed.
• Post-SAE/AE: approximately 48h.

Polytrauma rule: use latest needed timing among injury patterns, but do not extend beyond 48h without explicit bleeding-risk rationale and attending-level documentation.

Anti-Xa Monitoring

Not routine for all patients. Check peak anti-Xa (4h after 3rd dose) for:

• BMI >=40 or weight >100 kg (mandatory if >130 kg).
• ICU patients with multiple VTE risk factors.
• CrCl 15-29 on LMWH.
• TBI/SCI reduced-dose pathway.

Target: 0.2-0.4 IU/mL. If <0.2, increase LMWH by 10 mg and recheck.

Peri-Neuraxial / CSF Drain Practical Rules

• Hold LMWH >=12h before neuraxial placement.
• Avoid LMWH while neuraxial catheter is indwelling.
• Restart LMWH >=4h after catheter removal.
• Bridge with UFH + SCDs while catheter remains in place.
• If EVD/ICP drain present, UFH-first strategy is preferred.

Discharge Planning

Confirm plan in discharge summary and medication reconciliation.

IVC Filter Rule

• Avoid prophylactic IVC filters.
• Temporary filter only for acute VTE + temporary absolute contraindication to anticoagulation.

Hard Stops

• Do not hold prophylaxis >48h without clear bleeding-risk documentation.
• Do not miss scheduled doses without documented reason.
• Do not ignore VTE prophylaxis at transition points (OR, ICU transfer, discharge).
• Do not use aspirin/DOAC pathways for polytrauma, SCI, or TBI by default.

PIPS Trigger Events

• Any inpatient DVT/PE event.
• Chemoprophylaxis hold >48h without documented bleeding risk.
• Weight >100 kg receiving less than 40 mg BID without anti-Xa strategy.
• High-risk patient discharged without extended prophylaxis plan.

Daily Rounds Check

• Mechanical prophylaxis in place?
• Chemoprophylaxis active or hold reason documented?
• Last dose given on time?
• Is the current dose aligned with weight/renal protocol?
• New contraindication today?
• Discharge prophylaxis plan needed?

Source Basis

Condensed from current institutional VTE prophylaxis guideline (revision dated February 9, 2026).