What is the recommended prophylaxis for Deep Vein Thrombosis (DVT)?

DVT Prophylaxis: Evidence-Based Recommendations

All hospitalized patients should receive risk-stratified VTE prophylaxis using pharmacological agents (LMWH, UFH, or fondaparinux) or mechanical methods (intermittent pneumatic compression devices or graduated compression stockings) based on their thrombotic and bleeding risk, with early ambulation as a universal baseline measure. 1

Risk Assessment Framework

Every hospitalized patient requires assessment of both thrombotic and bleeding risk before initiating prophylaxis. 2

• Surgical patients: Use the Caprini score to stratify VTE risk, which incorporates patient age, procedure type, malignancy, prior VTE history, and mobility status 2
• Medical patients: The Padua Prediction Score helps identify high-risk medical patients who benefit most from pharmacologic thromboprophylaxis 1
• Trauma patients: Age >60-65 years, traumatic brain injury, chest injury with AIS >3, mechanical ventilation, major surgery, and prior VTE history are independent predictors requiring prophylaxis 1

Prophylaxis Strategies by Patient Population

Acutely Ill Medical Patients

Pharmacological prophylaxis with LMWH, low-dose UFH (twice or thrice daily), or fondaparinux should be administered throughout hospitalization for at-risk medical patients. 1

• Enoxaparin: 40 mg subcutaneously once daily 1
• Dalteparin: 5000 IU subcutaneously once daily 1
• Fondaparinux: 2.5 mg subcutaneously once daily 1, 3
• Unfractionated heparin: 5000 units subcutaneously twice or thrice daily 1

For patients at high bleeding risk, use mechanical thromboprophylaxis with graduated compression stockings and/or intermittent pneumatic compression devices instead of pharmacological agents. 1

Surgical Patients (Non-Orthopedic)

Prophylaxis intensity must match the surgical risk level, with pharmacological methods preferred for moderate-to-high risk patients. 1

• Low-risk patients (Caprini 1-2): Early ambulation plus either mechanical or pharmacological prophylaxis 2
• Moderate-risk patients (Caprini 3-4): Pharmacological prophylaxis alone or combined with mechanical methods 2
• High-risk patients (Caprini ≥5): Pharmacological prophylaxis combined with mechanical prophylaxis 2

Standard dosing regimens:

• Enoxaparin: 40 mg subcutaneously once daily, starting 2-12 hours preoperatively 1, 4
• Dalteparin: 2500 IU once daily for low-risk; 5000 IU once daily for high-risk patients 1
• Fondaparinux: 2.5 mg subcutaneously once daily, initiated 6-8 hours post-surgery after hemostasis is established 1, 3

Orthopedic Surgery Patients

For hip or knee arthroplasty, initiate prophylaxis post-operatively and continue for 10-14 days minimum, with extended prophylaxis up to 35 days for hip procedures. 1

• Enoxaparin: 30 mg subcutaneously twice daily starting 12 hours before or after surgery 1
• Rivaroxaban: 10 mg once daily starting 6-10 hours post-surgery is noninferior to LMWH 1
• Hip fracture surgery: Extended prophylaxis for up to 24 additional days (total 32 days) is recommended 1, 3

LMWH is preferable over unfractionated heparin due to higher effectiveness in preventing DVT. 1

Cancer Patients

All hospitalized cancer patients with major medical illness or reduced mobility should receive prophylactic anticoagulation unless contraindicated by bleeding risk. 1

• Surgical cancer patients: Begin prophylaxis preoperatively when appropriate and continue for at least 7-10 days 1
• Major cancer surgery: Extended prophylaxis for up to 4 weeks is recommended for high-risk patients (restricted mobility, obesity, prior VTE) 1, 4
• LMWH is the preferred agent for cancer patients undergoing major surgery with history of DVT 1

Patients admitted solely for chemotherapy or minor procedures do not require routine prophylaxis. 1

Trauma Patients

Pharmacological prophylaxis with LMWH is more effective than UFH (RR 0.68) and should be initiated once bleeding risk is controlled. 1

• High-risk trauma patients: Combine mechanical and pharmacological prophylaxis (RR 0.34 for DVT) 1
• Contraindications requiring delay: Active bleeding, coagulopathy, hemodynamic instability, solid organ injury, traumatic brain injury, or spinal trauma 1
• Use mechanical prophylaxis alone (IPC, elastic stockings, early mobilization) until stabilization allows pharmacological agents 1

Factor Xa inhibitors may be considered as alternatives to LMWH, though they show higher PE rates (2% vs -3.5%) and are less effective for PE prevention. 1

Pediatric Patients (Age ≥13 Years)

Mechanical prophylaxis with intermittent pneumatic compression devices or antiembolism stockings is recommended for at-risk children aged ≥13 years. 1

• Pharmacological prophylaxis: Reserved for children ≥13 years with multiple thrombotic risk factors and no bleeding risk 1
• LMWH is preferred over UFH for pediatric patients requiring anticoagulation 1

Duration of Prophylaxis

Standard prophylaxis duration is 5-9 days for most surgical patients, with extended prophylaxis indicated for specific high-risk scenarios. 1, 3

• General surgery: Continue until patient is fully ambulatory or hospital discharge 1, 2
• Major cancer surgery: Extend to 4 weeks post-operatively 1, 4
• Hip fracture surgery: Total duration up to 32 days (peri-operative plus extended prophylaxis) 1, 3
• Medical patients: Continue throughout hospitalization 1

Special Populations and Dose Adjustments

Renal Impairment

• Fondaparinux: Reduce to 1.5 mg once daily for CrCl 30-50 mL/min 1
• Enoxaparin: Reduce to 30 mg once daily for CrCl <30 mL/min 4

Obesity

• Patients >150 kg: Consider increasing enoxaparin to 40 mg subcutaneously every 12 hours 4

Patients with Prior DVT History

A history of provoked DVT increases post-operative VTE risk six-fold, placing patients in high or very high-risk category. 4

• Use highest prophylactic dose of LMWH (enoxaparin 40 mg once daily) 4
• Combine pharmacological and mechanical prophylaxis for maximum protection 4
• Extend prophylaxis to 4 weeks after major abdominal or pelvic surgery 4

Critical Pitfalls to Avoid

Despite high-quality evidence demonstrating safety and efficacy, only 58.5% of at-risk surgical patients and 39.5% of at-risk medical patients receive appropriate VTE prophylaxis. 1

• Never administer fondaparinux earlier than 6 hours post-surgery, as this significantly increases major bleeding risk 3
• Do not use pharmacological prophylaxis as monotherapy in very high-risk patients when mechanical methods can be safely added 4
• Avoid overuse of pharmacological prophylaxis in low-risk procedures (e.g., TURP has only 0.3-0.5% VTE incidence), as this unnecessarily increases bleeding risk 5
• Do not overlook patient-specific risk factors that may elevate a seemingly low-risk procedure to moderate or high risk 5
• Failure to provide extended prophylaxis after major cancer surgery or hip fracture surgery misses a critical window of elevated VTE risk 1, 4
• Do not adjust LMWH dosing without considering renal function or extreme body weight, as this leads to under- or over-anticoagulation 4

Mechanical Prophylaxis Considerations

Graduated compression stockings (30-40 mm Hg knee-high) worn for 2 years reduce postthrombotic syndrome risk by 50%. 1

• Mechanical methods alone are effective in reducing DVT (RR 0.55) but have not been shown to prevent fatal PE 1
• Reserve mechanical-only prophylaxis for patients with absolute contraindications to pharmacological agents (neurosurgery, active bleeding) 1, 6
• Combine mechanical and pharmacological methods in very high-risk patients for additive benefit 1, 6