From the Research
This patient likely has a deep vein thrombosis (DVT) despite ASA prophylaxis following total knee arthroplasty, and immediate management should include obtaining a lower extremity ultrasound to confirm DVT, discontinuing ASA, and starting therapeutic anticoagulation with either low molecular weight heparin (enoxaparin 1mg/kg twice daily or 1.5mg/kg once daily) or direct oral anticoagulant (apixaban 10mg twice daily for 7 days, then 5mg twice daily) as suggested by 1. The nausea and vomiting require antiemetic therapy such as ondansetron 4mg every 8 hours as needed, and consideration of IV anticoagulation if oral medication cannot be tolerated. The mild anemia should be monitored with serial hemoglobin checks and may require iron supplementation (ferrous sulfate 325mg daily). Pain management should continue with scheduled acetaminophen 1000mg every 6 hours and appropriate opioids while avoiding NSAIDs during anticoagulation. Some studies suggest that aspirin may prevent DVT in mechanically ventilated ICU patients 2, but in this case, ASA alone provides inadequate prophylaxis in patients who develop DVT symptoms. Additionally, there is no difference between low- and regular-dose aspirin for VTE prophylaxis after THA 3. However, the most recent and highest quality study 1 suggests that pharmacological prophylaxis is recommended if the risk of VTE outweighs the risk of bleeding, and this approach is necessary because the combination of post-operative symptoms (pain, swelling, nausea, vomiting, anemia) suggests both thrombotic complications and potential gastrointestinal effects that require comprehensive management. Key considerations include:
- Discontinuing ASA and starting therapeutic anticoagulation
- Managing nausea and vomiting with antiemetic therapy
- Monitoring and managing mild anemia
- Continuing pain management with acetaminophen and opioids while avoiding NSAIDs during anticoagulation.