What is the appropriate management for bruising or apparent clotting after an intravenous iron infusion?

Management of Bruising and Apparent Clotting After IV Iron Infusion

Bruising after IV iron infusion is most commonly due to extravasation (leakage of iron into surrounding tissue) at the infusion site, which causes persistent skin discoloration and should be managed by stopping the infusion immediately if still ongoing, applying supportive care, and reassuring the patient that while the discoloration may be persistent, it is not dangerous. 1, 2

Immediate Assessment

When a patient presents with bruising or apparent clotting after IV iron:

• Stop any ongoing infusion immediately if the bruising is noticed during administration 1
• Examine the IV site carefully for signs of extravasation including swelling, discoloration, pain, or coolness around the insertion site 1, 2
• Assess for systemic symptoms that would indicate an infusion reaction rather than local extravasation, including flushing, myalgias, arthralgias, back pain, chest pressure, shortness of breath, or hypotension 1

Understanding the Mechanism

Skin staining (discoloration) occurs when IV iron leaks outside the vein (paravenous leakage/extravasation) and deposits in surrounding tissue. 1 This is a mechanical complication, not an allergic or clotting disorder. The iron particles cause persistent brown or dark discoloration that can last months to years. 2

True clotting complications are not a recognized adverse effect of IV iron administration based on current evidence. 1

Management Algorithm

If Extravasation is Confirmed:

• Immediately discontinue the infusion if still in progress 1
• Do NOT attempt to aspirate the extravasated iron from the tissue
• Apply supportive care to the affected area 2
• Document the event including the iron formulation used, volume extravasated, and location 1
• Counsel the patient that skin discoloration may be persistent but is not medically dangerous 1, 2
• Consider dermatology referral if the patient is distressed by cosmetic appearance, though treatment options are limited 2

If Systemic Infusion Reaction is Present:

If the patient has symptoms beyond local bruising (flushing, myalgias, hypotension, respiratory symptoms):

• Stop the infusion and switch IV line to normal saline to keep vein open 1, 3
• Monitor vital signs for at least 15 minutes 1, 4
• For mild reactions (myalgias, arthralgias, flushing): observe and consider IV hydrocortisone 200 mg if symptoms persist beyond 15 minutes 1
• For moderate reactions (tachycardia, mild hypotension, nausea): administer ondansetron 4-8 mg IV for nausea, IV fluids for mild hypotension, and consider hydrocortisone 1
• Avoid diphenhydramine and vasopressors, as these can paradoxically worsen minor reactions into serious adverse events 1, 4

Prevention of Future Extravasation

• Ensure proper IV line placement before starting infusion 1
• Use appropriate catheter size and secure it well 1
• Monitor the infusion site closely during the first 10 minutes and throughout administration 3
• Start at slower infusion rates (50% of standard rate initially) if the patient has had a previous reaction 1, 4

Key Clinical Pitfalls to Avoid

Do not treat local extravasation as an allergic reaction. Extravasation is a mechanical complication requiring only supportive care and patient education, not antihistamines or corticosteroids. 1, 2

Do not administer first-generation antihistamines (diphenhydramine) or vasopressors for minor infusion reactions, as these medications can convert minor reactions into hemodynamically significant serious adverse events including exacerbation of hypotension, tachycardia, and shock. 1, 4

Do not assume the patient cannot receive IV iron in the future. If extravasation occurred, future infusions can be given safely with meticulous IV line placement. 1 If a systemic infusion reaction occurred, the patient can often be rechallenged with the same formulation at a slower rate, or switched to an alternative iron formulation. 1, 5

Reassurance About Safety

Severe hypersensitivity reactions to modern IV iron formulations are exceedingly rare, occurring in less than 1 in 200,000 to 1 in 250,000 administrations. 1, 6, 7 Most reactions are due to complement activation-related pseudo-allergy (CARPA), not true IgE-mediated anaphylaxis, and are self-limited. 1, 7