What could be causing the persistent tissue firmness in a patient on apixaban (direct oral anticoagulant) after a fall, with initial bruising and swelling that has subsided, and should an ultrasound be performed?

Persistent Tissue Firmness After Trauma in a Patient on Apixaban

The persistent tissue firmness extending beyond the initial injury site most likely represents an organizing hematoma that is evolving from acute to chronic phase, and yes, an ultrasound should be performed to rule out an expanding or organized hematoma that may require intervention. 1

Understanding What Is Happening

Hematoma Evolution in Anticoagulated Patients

• Patients on apixaban are at increased risk for developing larger hematomas following trauma because factor Xa inhibition impairs the coagulation cascade, allowing more extensive bleeding into soft tissues at the time of injury. 2, 3

• The natural history of a hematoma involves initial expansion (first 24-72 hours), followed by organization and gradual resorption over weeks to months. The firmness you're observing represents organized blood clot with fibrin deposition and early fibrotic changes. 1

• The extension of firmness beyond the original impact site is concerning because it suggests either:

  • Delayed expansion of the hematoma that occurred while the patient was still anticoagulated
  • Organization of a larger hematoma than initially appreciated
  • Possible development of a chronic expanding hematoma (rare but serious complication) 1

Why There Is No Pain

• Absence of pain does not exclude a significant hematoma. Once the acute inflammatory phase subsides (typically after 7-14 days), organized hematomas often become painless even as they continue to organize and potentially expand. 1

• The lack of pain may actually indicate the hematoma is organizing rather than actively bleeding, which is consistent with the 3-week timeline since injury. 1

Diagnostic Approach: Should Ultrasound Be Done?

Yes, Ultrasound Is Indicated

An ultrasound should be performed to characterize the hematoma and rule out complications. 1 Specifically, ultrasound will help determine:

• Size and extent of the organized hematoma to establish whether it is stable or expanding 1
• Presence of liquefaction or septations that might indicate need for drainage 1
• Vascular involvement or pseudoaneurysm formation (rare but possible with trauma) 1
• Baseline documentation for comparison if the firmness continues to progress 1

Additional Considerations for Imaging

• If ultrasound shows a large or complex hematoma, CT or MRI may be needed to better define the extent and relationship to deeper structures, particularly if the hematoma is in the paraspinal region where spinal canal involvement could occur. 1

• The American College of Cardiology emphasizes that bleeding at critical sites (including intramuscular bleeding with compartment syndrome risk) requires more aggressive evaluation and management. 4, 1

Management Recommendations

Immediate Actions

• Continue holding apixaban if not already done until the hematoma is fully characterized and you've confirmed it is not expanding. 1, 5

• Check hemoglobin/hematocrit to assess for occult ongoing blood loss, even though the patient appears stable. 5

• Assess for signs of compartment syndrome (though less likely given the painless presentation): check for any sensory changes, motor weakness, or tense compartments. 4, 1

Regarding Apixaban Management

The decision to restart apixaban depends on several factors: 1

• Delay restarting anticoagulation if:

  • The hematoma is expanding on imaging 1
  • Surgical drainage is being considered 1
  • The patient is at high risk of rebleeding (back trauma with potential for recurrent injury) 1
  • The source/extent has not been fully characterized 1

• Consider restarting apixaban within 7 days if:

  • Imaging confirms a stable, non-expanding hematoma 1
  • The patient has high thrombotic risk (e.g., atrial fibrillation with CHA₂DS₂-VASc ≥2, recent VTE) 1
  • No surgical intervention is planned 1

When Drainage Might Be Needed

Surgical or procedural drainage should only be considered after: 1

• Confirming the hematoma is organized and causing complications (mass effect, infection risk, or functional impairment) 1
• Ensuring adequate time has passed for apixaban elimination (24-48 hours after last dose with normal renal function, longer if renal impairment present) 1, 6
• Achieving hemodynamic stability and reversal of coagulopathy if reversal agents were used 1

Common Pitfalls to Avoid

• Do not assume painless = benign. Organized hematomas can be painless yet still require intervention if they are expanding or causing mass effect. 1

• Do not restart apixaban without imaging confirmation that the hematoma is stable, as apixaban has a half-life of approximately 12 hours and restarting prematurely could cause re-expansion. 6

• Do not use reversal agents (andexanet alfa) for stable, non-bleeding hematomas. These are reserved for active, life-threatening bleeding or bleeding at critical sites with hemodynamic compromise. 4, 1, 2

• Remember that apixaban's effect is prolonged in elderly patients and those with renal impairment (half-life extends to 17 hours), so the initial hematoma may have been larger than expected. 4, 6