Table 2.
Recommendations on thromboprophylaxis in international guidelines
| Outpatient | In hospital | Intensive care unit | Post-discharge | |
|---|---|---|---|---|
| National Institutes of Health (February, 2021)58 | Not advised unless clear (other) indication | Routine dosed thromboprophylaxis; no routine antiplatelet therapy | Routine dosed thromboprophylaxis; no routine antiplatelet therapy | Extended thromboprophylaxis considered in patients at low risk for bleeding and high risk for venous thromboembolism, as per protocol for patients without COVID-19 |
| International Society on Thrombosis and Haemostasis (May, 2020)51, 52 | Not mentioned | Routine dosed thromboprophylaxis in the absence of contraindications | Routine dosed thromboprophylaxis; increased dose considered in high-risk patients | No routine prophylaxis; anticoagulant thromboprophylaxis (low-molecular-weight heparin or direct oral anticoagulants) considered in high-risk patients* with low risk of bleeding |
| Anticoagulation forum interim clinical guidance (July, 2020)53 | Not mentioned | Routine dosed thromboprophylaxis in the absence of contraindications | Increased intensity thromboprophylaxis | No routine prophylaxis; anticoagulant thromboprophylaxis considered in high-risk patients with low risk of bleeding |
| The American College of Chest Physicians (CHEST) guideline and expert panel report (June, 2020)59 | Not mentioned | Routine dosed thromboprophylaxis in the absence of contraindications | Routine dosed thromboprophylaxis | No routine prophylaxis; anticoagulant thromboprophylaxis considered in high-risk patients with low risk of bleeding |
| International Society on Thrombosis and Haemostasis (August, 2020)54 | All patients should be evaluated regularly, D-dimers should be measured and if >1500 ng/mL, low-molecular-weight heparin prophylaxis should be considered | Routine dosed thromboprophylaxis; increased intensity thromboprophylaxis should be considered in patients with additional risk factors† | Increased intensity thromboprophylaxis should be considered | Thromboprophylaxis is reasonable in patients with persistent immobility, high inflammatory activity or additional risk-factors, or both† |
| American Society of Hematology guidelines (February, 2021)60 | Not mentioned | Routine dosed thromboprophylaxis in the absence of contraindications | Routine dosed thromboprophylaxis; increased intensity thromboprophylaxis considered in high-risk patients with low bleeding risk | Not mentioned |
| National Institute for Health and Care Excellence guidelines (November, 2020)61 | Assess the risk of venous thromboembolism and bleeding; consider pharmacological prophylaxis if the risk of venous thromboembolism outweighs the risk of bleeding | Routine dosed thromboprophylaxis in the absence of contraindications | Increased intensity thromboprophylaxis should be considered | Assess the risk of venous thromboembolism and bleeding; consider pharmacological prophylaxis if the risk of venous thromboembolism outweighs the risk of bleeding |
| WHO guidance (January, 2021)62 | No routine thromboprophylaxis | Routine dosed thromboprophylaxis | Routine dosed thromboprophylaxis | No routine thromboprophylaxis |
| National Institute for Health and Care Excellence guideline (March, 2021)55 | Not mentioned | Therapeutic dose thromboprophylaxis should be considered unless contraindications | Increased intensity thromboprophylaxis should be considered | Not mentioned |
Potential agents for thromboprophylaxis in an in-hospital setting include low-molecular-weight heparin and unfractionated heparin; intermediate dosing is commonly interpreted as twice the standard thromboprophylaxis dose.
*
Includes advanced age, stay in the ICU, cancer, previous history of venous thromboembolism, thrombophilia, severe immobility, an elevated D-dimer (>2 times the upper normal limit).
†
Body-mass index of more than 30 kg/m2, history of venous thromboembolism, known thrombophilia, active cancer, or rapidly increasing D-dimer concentrations.