From the Guidelines
If you have concerns for deep vein thrombosis (DVT) or pulmonary embolism (PE) but cannot get imaging immediately, you should not delay anticoagulation if your clinical suspicion is high, as suggested by the most recent guidelines 1. For patients with high clinical probability of DVT/PE, empiric anticoagulation should be started while awaiting definitive diagnosis.
Key Considerations
- Typically, low molecular weight heparin (such as enoxaparin 1 mg/kg twice daily or 1.5 mg/kg once daily) or direct oral anticoagulants (such as rivaroxaban 15 mg twice daily for 21 days, then 20 mg daily) can be initiated.
- If using warfarin, bridge with heparin or LMWH until the INR is therapeutic (2-3).
- For patients with moderate risk, consider using validated clinical prediction tools like Wells score to guide your decision.
- The risk of bleeding from short-term anticoagulation is generally lower than the risk of untreated thromboembolism in high-risk patients, as noted in the guidelines 1.
Bleeding Risk Assessment
However, carefully assess bleeding risk before starting therapy, especially in patients with recent surgery, active bleeding, or severe thrombocytopenia.
Next Steps
Once imaging becomes available, anticoagulation can be discontinued if results are negative and no other indications exist.
Clinical Judgment
It's essential to use clinical judgment and consider the individual patient's risk factors and clinical presentation when making decisions about empiric anticoagulation, as emphasized in the guidelines 1.
From the Research
Anticoagulation in Suspected DVT or PE
- In cases where imaging for suspected Deep Vein Thrombosis (DVT) or Pulmonary Embolism (PE) is delayed, the decision to initiate anticoagulation should be based on clinical evaluation and risk assessment 2.
- Clinical evaluation using tools like the Wells' score can guide the decision to prophylactically anticoagulate patients with suspected DVT, even if imaging is delayed 2.
- Studies have shown that direct oral anticoagulants (DOACs) are at least as effective and safe as conventional therapy for the treatment and long-term prevention of venous thrombo-embolism (VTE) 3.
- The use of DOACs, such as apixaban, rivaroxaban, and edoxaban, has been evaluated in several studies, and they have been found to be effective in preventing recurrent VTE, including DVT and PE 4, 5, 6.
Delaying Anticoagulation
- Delaying anticoagulation until imaging can be performed may not be necessary in patients with a high clinical suspicion of DVT or PE, as prophylactic anticoagulation can be initiated based on clinical evaluation 2.
- However, the decision to delay anticoagulation should be made on a case-by-case basis, taking into account the individual patient's risk factors and clinical presentation.
- It is essential to note that delaying anticoagulation may increase the risk of complications, such as pulmonary embolism, in patients with suspected DVT or PE 2.
Evidence Summary
- The available evidence suggests that DOACs are effective and safe for the treatment and long-term prevention of VTE, including DVT and PE 4, 5, 6, 3.
- Clinical evaluation and risk assessment should guide the decision to initiate anticoagulation in patients with suspected DVT or PE, even if imaging is delayed 2.