Prophylactic Anticoagulation for Patients on Bed Rest
For patients on bed rest for about a month, prophylactic anticoagulation with low molecular weight heparin (LMWH) such as enoxaparin 40mg subcutaneously once daily or dalteparin 5,000 U once daily is strongly recommended to prevent venous thromboembolism. 1
Risk Assessment
Prolonged immobilization due to bed rest is a significant risk factor for developing venous thromboembolism (VTE). When evaluating a patient on bed rest, consider these additional risk factors that increase VTE risk:
- Active cancer
- Previous history of VTE
- Advanced age (>60 years)
- Obesity
- Acute medical illness (heart failure, respiratory failure, infection)
- Recent surgery
- Thrombophilia
Recommended Prophylactic Regimens
First-line options:
- LMWH (preferred): 1
- Enoxaparin 40mg subcutaneously once daily
- Dalteparin 5,000 U subcutaneously once daily 2
Alternative options:
- Unfractionated heparin (UFH): 5,000 U subcutaneously every 8 hours 1
- Particularly useful in patients with severe renal impairment (CrCl <30 mL/min)
- Fondaparinux: 2.5mg subcutaneously once daily 1, 3
- Can be considered in patients with heparin allergy
Duration of Prophylaxis
For patients on bed rest for approximately one month, anticoagulant prophylaxis should be continued for the entire duration of immobilization 1. The American College of Chest Physicians guidelines suggest that prophylaxis should continue until full mobility is restored 4.
Mechanical Prophylaxis
In addition to pharmacological prophylaxis, consider adding mechanical methods:
- Intermittent pneumatic compression (IPC) (preferred mechanical method)
- Graduated compression stockings (GCS)
Mechanical methods should be used as the primary prevention strategy only in patients with high bleeding risk or contraindications to pharmacological prophylaxis 1.
Special Considerations
Patients with High Bleeding Risk
If pharmacological prophylaxis is contraindicated due to high bleeding risk:
- Use mechanical prophylaxis with IPC 1
- Consider inferior vena cava (IVC) filter only in patients with acute proximal DVT and absolute contraindication to anticoagulation 4
Patients with Renal Impairment
- For severe renal impairment (CrCl <30 mL/min), use UFH 5,000 U subcutaneously every 8 hours 1
- Low-dose fondaparinux (1.5mg once daily) may be considered but evidence is limited 3
Patients with Cancer
Cancer patients on bed rest are at particularly high risk for VTE and should receive LMWH as the preferred agent 4, 1.
Early Mobilization
While providing prophylactic anticoagulation, it's important to note that early ambulation is preferred over bed rest when possible 4. If the patient's condition allows, implement a progressive mobilization plan rather than strict bed rest to further reduce VTE risk.
Monitoring
- Assess for signs and symptoms of VTE (leg pain, swelling, warmth, redness)
- Monitor for bleeding complications
- Evaluate platelet counts periodically if using heparin products
Common Pitfalls to Avoid
- Inadequate risk assessment: Failing to recognize the high VTE risk associated with prolonged bed rest
- Inappropriate prophylaxis duration: Not continuing prophylaxis for the entire duration of immobilization
- Overlooking contraindications: Not considering bleeding risk before initiating pharmacological prophylaxis
- Relying solely on aspirin: Aspirin alone is not recommended for VTE prophylaxis 1
By following these recommendations, the risk of developing VTE during prolonged bed rest can be significantly reduced, improving patient outcomes and reducing morbidity and mortality associated with this preventable complication.