What is the management approach for superficial phlebitis?

Management of Superficial Phlebitis

For superficial phlebitis ≥5 cm in length, initiate prophylactic-dose fondaparinux 2.5 mg subcutaneously once daily for 45 days, combined with warm compresses, NSAIDs, limb elevation, and early mobilization. 1, 2, 3

Immediate Actions

• Remove any peripheral intravenous catheter immediately upon recognition of phlebitis signs (heat, sensitivity, redness, palpable venous cord). 2
• Obtain compression ultrasound to confirm diagnosis, measure thrombus length, assess distance from saphenofemoral junction, and exclude concomitant deep vein thrombosis (DVT)—critical because approximately 25% of patients have underlying DVT. 1, 2, 3, 4

Treatment Algorithm Based on Ultrasound Findings

For Thrombus <5 cm or Localized to Injection Site

• Apply warm compresses to the affected area. 2, 3
• Administer NSAIDs for pain control (avoid if platelets <20,000-50,000/mcL). 2, 3
• Elevate the affected limb. 2, 3
• Encourage early ambulation rather than bed rest to reduce DVT risk. 2, 3, 5
• Consider repeat ultrasound in 7-10 days to assess for progression. 3

For Thrombus ≥5 cm in Length

• Initiate fondaparinux 2.5 mg subcutaneously once daily for 45 days (first-line option, reduces progression to DVT from 1.3% to 0.2% and recurrent superficial thrombophlebitis from 1.6% to 0.3%). 1, 2, 3, 4
• Alternative: Rivaroxaban 10 mg orally once daily for 45 days if parenteral anticoagulation is not feasible. 2, 3
• Alternative: Prophylactic-dose low molecular weight heparin (LMWH) for 45 days, though less preferred than fondaparinux. 1, 3, 4
• Continue symptomatic measures (warm compresses, NSAIDs, elevation, early mobilization). 2, 3

For Thrombus Within 3 cm of Saphenofemoral Junction

• Escalate to therapeutic-dose anticoagulation for at least 3 months, treating as DVT-equivalent. 2, 3
• This is not superficial phlebitis requiring prophylactic dosing—this requires full therapeutic anticoagulation. 3

Special Population Considerations

Pregnant Patients

• Use prophylactic-dose LMWH instead of fondaparinux (fondaparinux crosses the placenta). 3, 4
• Continue treatment for the remainder of pregnancy and 6 weeks postpartum. 3, 4

Cancer Patients

• Follow the same anticoagulation recommendations as non-cancer patients. 3
• Cancer patients with superficial phlebitis have similar risks of death and DVT/PE recurrence as those with DVT. 3

Patients with Thrombocytopenia

• Avoid NSAIDs if platelets <20,000-50,000/mcL. 2, 3
• Consider dose modification or withholding anticoagulation if platelets <25,000/mcL. 3

Risk Factors Favoring Anticoagulation

• Thrombus length >5 cm. 1, 2, 3
• Location above the knee. 3
• Proximity to deep venous system (especially <3 cm from saphenofemoral junction). 2, 3
• History of venous thromboembolism or superficial phlebitis. 3
• Active cancer. 1, 3
• Recent surgery. 1, 3
• Severe symptoms. 3

Laboratory Evaluation Before Treatment

• CBC with platelet count. 3
• PT, aPTT. 3
• Liver and kidney function tests (fondaparinux is renally eliminated). 2, 3

Critical Pitfalls to Avoid

• Do not omit ultrasound evaluation—approximately 25% of patients have underlying DVT requiring therapeutic anticoagulation, not prophylactic dosing. 1, 2, 3, 4
• Do not under-treat thrombosis within 3 cm of the saphenofemoral junction—this requires therapeutic anticoagulation for at least 3 months, not prophylactic dosing. 2, 3
• Do not prescribe bed rest—early mobilization reduces DVT risk. 2, 3, 5
• Do not use inadequate treatment duration—evidence-based duration is 45 days for thromboses ≥5 cm, not shorter courses. 1, 3
• Do not treat superficial thrombosis of the cephalic and basilic veins with anticoagulation—these do not require anticoagulant therapy. 1, 4

Monitoring and Follow-Up

• Monitor for extension into the deep venous system, which necessitates immediate escalation to therapeutic anticoagulation. 2, 3
• Consider repeat ultrasound at 7-10 days if initially managed conservatively or if clinical progression occurs. 3
• Approximately 10% of patients develop thromboembolic complications at 3 months despite anticoagulation. 3

Catheter-Related Phlebitis Prevention

• Change peripheral intravenous catheters every 72-96 hours in adults to reduce phlebitis risk. 2
• Do not apply antimicrobial ointments or creams prophylactically to catheter insertion sites. 2