What are the recommended scoring tools and prophylaxis regimes for inpatients at risk of Deep Vein Thrombosis (DVT)?

DVT Risk Assessment and Prophylaxis in Hospitalized Medical Patients

Recommended Scoring Tools

For general medical inpatients, use either the Padua Prediction Score or the IMPROVE VTE score to stratify thromboembolism risk, with the Padua score being the most extensively validated tool. 1, 2

Padua Prediction Score (Preferred for Medical Inpatients)

• High risk: Score ≥4 points - VTE incidence 11% without prophylaxis, reduced to 2.2% with prophylaxis (HR 0.13) 1, 2
• Low risk: Score 0-3 points - VTE incidence 0.3% 1
• The Padua score identifies 39.7% of medical patients as high-risk and has been externally validated 1, 3

Key Padua risk factors include:

• Active cancer (+3 points)
• Previous VTE (+3 points)
• Reduced mobility (+3 points)
• Known thrombophilic condition (+3 points)
• Recent trauma/surgery (+2 points)
• Age ≥70 years (+1 point)
• Heart/respiratory failure (+1 point each)
• Acute MI or stroke (+1 point each)
• Acute infection/rheumatologic disorder (+1 point each)
• Obesity (BMI ≥30) (+1 point)
• Ongoing hormonal treatment (+1 point) 1, 3

IMPROVE VTE Score (Alternative Validated Tool)

• High risk: Score ≥4 points - 5.7% VTE rate 1, 2
• Moderate risk: Score 2-3 points - 1.5% VTE rate 1
• Low risk: Score 0-1 points - 0.5% VTE rate 1
• Prophylaxis indicated for score ≥2 2, 4

Caprini Score (Primarily for Surgical Patients)

• For nonorthopedic surgery patients, the Caprini score stratifies risk into: very low (0 points; 0.5%), low (1-2 points; 1.5%), moderate (3-4 points; 3%), and high (≥5 points; 6%) 1
• While validated in surgical populations, the Caprini score can identify 84.3% of VTE cases in medical inpatients versus only 49.1% with Padua 5
• A Caprini score ≥11 identifies extremely high-risk patients requiring more aggressive prophylaxis 6

Bleeding Risk Assessment

Always assess bleeding risk using the IMPROVE Bleeding Risk Assessment Model before initiating pharmacologic prophylaxis: 1, 2

• Low bleeding risk: Score <7 - 0.4% major bleeding, 1.5% any bleeding 1, 2
• High bleeding risk: Score ≥7 - 4.1% major bleeding, 7.9% any bleeding 1, 2

Acceptable Prophylaxis Regimens

For Acutely Ill General Medical Patients

First-line pharmacologic options (choose one): 1

• Enoxaparin 40 mg subcutaneous once daily (preferred by ASH over DOACs) 1, 7
• Dalteparin 5000 IU subcutaneous once daily 1
• Fondaparinux 2.5 mg subcutaneous once daily (reduce to 1.5 mg if CrCl 30-50 mL/min) 1, 8
• Unfractionated heparin 5000 units subcutaneous three times daily (particularly for cancer patients) 1

Clinical Decision Algorithm

Step 1: Calculate VTE risk score

• Use Padua or IMPROVE score for all hospitalized medical patients 1, 2, 4

Step 2: Calculate bleeding risk

• Use IMPROVE bleeding score 1, 2

Step 3: Make prophylaxis decision based on combined risk:

• High VTE risk (Padua ≥4 or IMPROVE ≥2) + Low bleeding risk (<7): Initiate pharmacologic prophylaxis with LMWH or UFH 2, 4
• High VTE risk + High bleeding risk (≥7): Use mechanical prophylaxis (intermittent pneumatic compression devices) instead of pharmacologic methods 2, 4
• Low VTE risk (Padua 0-3 or IMPROVE 0-1): No routine prophylaxis needed 1, 2

Step 4: Duration

• Continue prophylaxis throughout hospitalization 4
• Do not extend prophylaxis beyond hospital discharge for general medical patients 4

For Surgical Patients (Nonorthopedic)

Moderate-to-high VTE risk without significant bleeding risk: 1

• LMWH or low-dose UFH combined with mechanical prophylaxis (intermittent pneumatic compression) 1
• Continue for 10-14 days, consider extending up to 35 days for high-risk patients 1

High bleeding risk:

• Mechanical prophylaxis alone until bleeding risk decreases, then add pharmacologic prophylaxis 1

For Orthopedic Surgery Patients

Multiple acceptable options include: 1

• Enoxaparin 30 mg subcutaneous twice daily starting 12 hours before or after surgery 1
• Rivaroxaban 10 mg once daily (noninferior to LMWH) starting 6-10 hours after surgery 1
• Continue for 10-14 days, consider extending up to 35 days 1

Special Population: Cancer Patients

• All hospitalized cancer patients should receive thromboprophylaxis unless contraindications exist 1
• Cancer patients undergoing surgery should receive 4 weeks of LMWH 1
• For outpatient cancer patients, use the Khorana scoring system to identify those requiring prophylaxis 1
• Unfractionated heparin 5000 units subcutaneous three times daily is specifically recommended for hospitalized cancer patients 1

Critical Pitfalls to Avoid

Do NOT use universal VTE prophylaxis regardless of risk - this approach has minimal impact on reducing VTE and leads to overprophylaxis of low-risk patients with unnecessary bleeding complications 1, 2

Do NOT use graduated compression stockings as primary prophylaxis - they are not effective as sole VTE prevention and should not be relied upon, particularly in cancer patients 1, 2

Do NOT overlook bleeding risk assessment - pharmacologic prophylaxis increases bleeding events (RR 1.34, absolute increase 9 events per 1000 persons) despite reducing PE 2

Do NOT use warfarin for VTE prophylaxis in acutely ill medical patients 1

Do NOT continue prophylaxis after hospital discharge in general medical patients, as the risk-benefit ratio becomes unfavorable 4

Contraindications to pharmacologic prophylaxis include:

• Active bleeding 4
• Platelet count <50,000/mcL 4
• Severe renal impairment (adjust dosing or avoid certain agents) 1, 8