What to do for a hemodialysis patient with an arteriovenous (AV) fistula experiencing intense itching after using Thrombophob (heparin) ointment on the fistula site?

Management of Intense Itching After Thrombophob (Heparin) Ointment Application on AV Fistula

Immediately discontinue the Thrombophob ointment and do not reapply it, as this represents a contact dermatitis or allergic reaction to the topical heparin formulation.

Immediate Actions

• Stop the offending agent: Discontinue Thrombophob ointment completely and remove any residual ointment from the skin with gentle soap and water 1
• Assess the fistula integrity: Check for the presence of a thrill (vibration) and bruit (whooshing sound) to ensure the fistula remains patent despite the reaction 2
• Examine for complications: Look for signs of skin breakdown, redness, warmth, swelling, or any compromise to skin integrity that could predispose to infection or rupture 1, 3

Symptomatic Treatment

• Topical corticosteroids: Apply a mild-to-moderate potency topical corticosteroid (e.g., hydrocortisone 1-2.5% or triamcinolone 0.1%) to the affected area to reduce inflammation and pruritus
• Oral antihistamines: Consider diphenhydramine 25-50 mg or cetirizine 10 mg for symptomatic relief of itching
• Cool compresses: Apply cool, moist compresses to soothe the irritated skin 1

Critical Monitoring During Recovery

• Daily fistula assessment: The patient must check the thrill daily by palpating the access site and listening for the bruit 2
• Watch for thrombosis: Loss of thrill or bruit indicates potential thrombosis requiring urgent intervention within 24-48 hours 2, 3
• Monitor skin integrity: Examine for progressive skin thinning, discoloration, or breakdown that could lead to catastrophic rupture and hemorrhage 3, 4

Alternative Approaches to Fistula Maintenance

Do not use topical heparin products in this patient going forward. While one retrospective study suggested topical heparin spray may improve AVF patency 5, this patient has demonstrated a clear adverse reaction that outweighs any theoretical benefit.

• Standard care is sufficient: The American Journal of Kidney Diseases recommends washing the access arm with soap and water before each dialysis session, which is adequate for infection prevention 1, 2
• Proper site preparation: Dialysis staff should disinfect the site with alcohol-based chlorhexidine (>0.5%), 10% povidone iodine for 2-3 minutes, or 70% alcohol before cannulation 1
• Systemic antiplatelet therapy: If thrombosis prevention is a concern, oral antiplatelet agents (aspirin, clopidogrel) are proven to prevent recurrent thrombotic episodes and should be considered instead of topical agents 6

Common Pitfalls to Avoid

• Never continue a topical agent causing allergic reaction: Persistent exposure can lead to severe contact dermatitis, skin breakdown, and increased infection risk at the cannulation site 1
• Do not ignore skin changes: Compromised skin integrity over the fistula is a warning sign of impending rupture, which can cause exsanguination and death 3, 4
• Avoid cannulating through affected skin: Never puncture through areas of dermatitis, as this dramatically increases infection risk and can precipitate access failure 1, 3

When to Escalate Care

• Immediate referral if thrill/bruit lost: This indicates thrombosis requiring urgent thrombectomy or thrombolysis within 24-48 hours to salvage the access 1, 2
• Vascular surgery consultation: If skin integrity is severely compromised or if aneurysmal changes are present, surgical evaluation is needed to prevent rupture 3, 4
• Signs of infection: Redness, warmth, tenderness, swelling, or drainage at the site require immediate evaluation, as access-related infections are a primary cause of morbidity and mortality in dialysis patients 1, 7