What tests should be ordered for a patient with a postoperative femoral hematoma?

Diagnostic Tests for Postoperative Femoral Hematoma

For a patient with a postoperative femoral hematoma, a complete blood count (CBC) with platelet count, coagulation studies (PT/INR, aPTT), and imaging with ultrasound or CT should be ordered as the initial diagnostic tests. 1

Initial Laboratory Tests

• Complete Blood Count (CBC): Essential to assess hemoglobin/hematocrit levels to determine the extent of blood loss and need for transfusion. A drop in hemoglobin of 2-3 g/dL is often seen with significant bleeding and may indicate need for transfusion. 1

• Platelet Count: Critical as thrombocytopenia (platelets <100 × 10^9/L) is significantly associated with increased risk of hematoma formation and bleeding complications. 2

• Coagulation Studies: Standard tests should include:

  • Prothrombin Time (PT)/International Normalized Ratio (INR)
  • Activated Partial Thromboplastin Time (aPTT)
  • Fibrinogen level 1

Imaging Studies

• Ultrasound: First-line imaging modality for evaluating femoral hematomas. Provides real-time assessment of hematoma size, location, and potential active bleeding. 1, 3

• CT Scan: Indicated when ultrasound findings are equivocal or when deeper extension of the hematoma is suspected (retroperitoneal extension). Provides better anatomical detail and can identify active extravasation. 1

Advanced Hemostatic Testing

• Viscoelastic Testing: If available, thromboelastography (TEG) or rotational thromboelastometry (ROTEM) should be considered, especially if coagulopathy is suspected. These tests provide a more comprehensive assessment of clot formation, strength, and breakdown. 1

• Fibrinogen Levels: Should be assessed before administration of cryoprecipitate if excessive bleeding continues. 1

Clinical Considerations

• Timing of Tests: Laboratory tests should be obtained as soon as the hematoma is identified, ideally before any intervention. 1

• Medication Review: Document any anticoagulant or antiplatelet medications the patient may be taking, as these significantly impact management. 1

• Serial Monitoring: Repeat hemoglobin/hematocrit measurements every 4-6 hours initially to monitor for ongoing bleeding. 1

Special Considerations

• For patients on oral anticoagulants, specific tests may be needed:

  • For vitamin K antagonists: INR is sufficient
  • For direct oral anticoagulants (DOACs): Specialized tests like dilute thrombin time or anti-Xa assays may be needed if available 1

• In patients with known bleeding disorders or suspected coagulopathy, additional tests such as factor assays or platelet function tests may be warranted. 1

Common Pitfalls to Avoid

• Delaying imaging: Do not delay appropriate imaging studies while waiting for laboratory results if the hematoma appears to be expanding or the patient is hemodynamically unstable. 1

• Overlooking retroperitoneal extension: Femoral hematomas can extend into the retroperitoneal space, causing significant hidden blood loss. CT imaging is crucial if this is suspected. 1

• Neglecting platelet function: Standard platelet counts do not assess platelet function, which may be impaired in patients on antiplatelet medications. Consider platelet function testing in these patients. 1

• Relying solely on PT/aPTT: These tests may not detect all coagulation abnormalities, particularly in the immediate postoperative period when hypercoagulability and subsequent fibrinolysis can occur. 4, 5