What are the recommendations for Deep Vein Thrombosis (DVT) prophylaxis in pre-operative patients?

DVT Prophylaxis in Pre-Operative Patients

All patients undergoing major surgery should receive pharmacologic thromboprophylaxis with either low-molecular-weight heparin (LMWH) or low-dose unfractionated heparin (LDUH) unless contraindicated by active bleeding or high bleeding risk. 1, 2

Risk Stratification and Prophylaxis Selection

Low-Risk Patients

• Minor procedures <30 minutes or fully mobile patients without additional risk factors: Early ambulation only is sufficient 2

Moderate-Risk Patients (VTE risk <3%)

• General surgical patients and mobile patients with additional risk factors: LDUH 5,000 units subcutaneously every 12 hours starting after surgery 1, 2
• Alternative: LMWH (enoxaparin 40 mg subcutaneously once daily) 2

High-Risk Patients (VTE risk 3-6%)

• Major abdominal/pelvic surgery or limited mobility with additional risk factors: LDUH 5,000 units subcutaneously every 8 hours starting after surgery 1, 2
• Preferred alternative: LMWH (enoxaparin 40 mg subcutaneously once daily) 1, 2

Very High-Risk Patients (VTE risk >6%)

• Cancer patients or major orthopedic surgery: LMWH (enoxaparin 40 mg subcutaneously once daily) PLUS intermittent pneumatic compression devices (IPCD) 1, 2
• Major orthopedic surgery alternatives: Fondaparinux 2.5 mg subcutaneously once daily, apixaban, dabigatran, or rivaroxaban 1

Timing of Initiation

Critical timing consideration: Initiate pharmacologic prophylaxis preoperatively or as early as possible postoperatively, but no earlier than 6-8 hours after surgery to minimize major bleeding risk 1, 2, 3

• For major orthopedic surgery: First dose must be given 6-8 hours after surgery once hemostasis is established 1, 3
• For general/abdominal surgery: Commence preoperatively or immediately postoperatively 1, 2

Duration of Prophylaxis

Standard Duration

• Minimum 7-10 days postoperatively or until full ambulation is achieved 1, 2
• Major orthopedic surgery: Minimum 10-14 days 1

Extended Duration

• Major orthopedic surgery (hip/knee replacement, hip fracture): Extend prophylaxis up to 35 days from day of surgery 1
• Cancer patients undergoing major abdominal/pelvic surgery: Extend prophylaxis up to 4 weeks (28 days) 1, 2
• Hip fracture surgery specifically: Total of 32 days (perioperative plus extended prophylaxis) 1

Mechanical Prophylaxis

Add mechanical prophylaxis to pharmacologic methods in very high-risk patients 1, 2

• Intermittent pneumatic compression devices (IPCD): Preferred mechanical method, should achieve 18 hours of daily compliance 1
• Graduated compression stockings: Effective adjunct but less preferred than IPCD 1, 2
• Use mechanical prophylaxis alone when pharmacologic methods are contraindicated due to active bleeding or high bleeding risk 1, 2

High Bleeding Risk Patients

For patients with increased bleeding risk or contraindications to pharmacologic prophylaxis: Use IPCD or no prophylaxis rather than pharmacologic treatment 1

Absolute Contraindications to Pharmacologic Prophylaxis

• Active bleeding 1, 2
• Severe thrombocytopenia (platelets <50,000/μL) 4
• Recent neurosurgery or active intracranial bleeding 4

Management Strategy

• Initiate mechanical prophylaxis (IPCD) immediately 1
• Transition to pharmacologic prophylaxis once bleeding risk diminishes 1, 2

Special Populations

Cancer Patients

• LMWH is the preferred agent over LDUH or fondaparinux 1, 2
• Extended prophylaxis (4 weeks) is recommended for major abdominal/pelvic cancer surgery 1, 2
• Dual prophylaxis (LMWH + IPCD) for highest-risk cancer patients 1, 2

Renal Insufficiency

• Avoid LMWH if creatinine clearance <30 mL/min 4, 2
• Use LDUH instead or dose-adjusted LMWH with anti-factor Xa monitoring 4, 2
• Fondaparinux low-dose (1.5 mg once daily) may be considered but lacks robust evidence 5

Elderly Patients (>65 years)

• Enoxaparin 30 mg subcutaneously every 12 hours as initial dose 4
• May require lower doses of heparin compared to younger patients 6

Patients Declining Injections

• Use oral agents: Apixaban or dabigatran (first-line), rivaroxaban or adjusted-dose warfarin (second-line) 1

Specific Surgical Categories

Major Orthopedic Surgery (Hip/Knee Replacement, Hip Fracture)

• First-line: LMWH (enoxaparin 40 mg once daily or 30 mg twice daily), fondaparinux 2.5 mg once daily, apixaban, dabigatran, or rivaroxaban 1
• Duration: 10-14 days minimum, extend to 35 days 1
• Add IPCD for dual prophylaxis during hospital stay 1

Abdominal/Pelvic Surgery

• Standard risk: LDUH 5,000 units every 8-12 hours or LMWH (enoxaparin 40 mg once daily) 1, 2
• Cancer patients: LMWH with extended prophylaxis (4 weeks) 1, 2
• Duration: Minimum 7-10 days 1, 2

Cardiac Surgery

• Most patients are moderate risk: LDUH or LMWH recommended 1
• Early mobilization and antiplatelet therapy mitigate some VTE risk 1

Common Pitfalls to Avoid

• Do NOT administer first dose <6 hours after major orthopedic surgery - significantly increases major bleeding risk 1, 3
• Do NOT use IVC filters for primary prevention - no evidence of benefit and documented harms including insertion site thrombosis, IVC occlusion, and filter migration 1
• Do NOT perform routine screening ultrasound before discharge - not cost-effective and does not improve outcomes 1
• Do NOT use mechanical prophylaxis alone in very high-risk patients unless pharmacologic methods are absolutely contraindicated 1
• Do NOT forget extended prophylaxis for major orthopedic surgery and cancer surgery patients - substantial reduction in VTE events 1