Assessment and Management of Phlebitis
Initial Diagnostic Evaluation
For any patient presenting with phlebitis, immediately obtain compression ultrasound to distinguish superficial venous thrombosis (SVT) from deep vein thrombosis (DVT), as approximately 25% of SVT cases have concurrent DVT. 1, 2, 3
Key Clinical Features to Assess
- Location and extent: Measure thrombus length and assess whether it involves superficial veins (saphenous system) versus deep veins (femoral, popliteal), and determine distance from the saphenofemoral junction 2, 3
- Presence of systemic signs: Check for fever ≥38.0°C, which mandates blood cultures to rule out septic phlebitis 3, 4
- Catheter association: Identify if phlebitis is related to peripheral IV, PICC line, or central venous catheter 1, 2
- Risk factors for progression: Document history of prior VTE, active cancer, recent surgery, immobilization, or varicose veins 2, 5, 6
Mandatory Laboratory Workup
- Complete blood count with platelet count 2, 3
- PT/aPTT 2, 3
- Liver and kidney function tests 2, 3
- Blood cultures if fever or sepsis signs present 3, 4
Treatment Algorithm Based on Type and Location
Superficial Venous Thrombosis (SVT) ≥5 cm or Above the Knee
Initiate fondaparinux 2.5 mg subcutaneously once daily for 45 days as first-line therapy, which reduces progression to DVT from 1.3% to 0.2% and recurrent SVT from 1.6% to 0.3%. 2, 7
- Alternative option: Rivaroxaban 10 mg orally once daily for 45 days if parenteral anticoagulation is not feasible 2, 7
- Less preferred alternative: Prophylactic-dose low molecular weight heparin (LMWH) for 45 days 2
SVT Within 3 cm of Saphenofemoral Junction
Treat as DVT-equivalent with therapeutic-dose anticoagulation for at least 3 months due to high risk of proximal extension. 2, 7
- Therapeutic DOAC options include:
SVT <5 cm in Length or Below the Knee
- Perform repeat ultrasound in 7-10 days to assess for progression 2
- Initiate anticoagulation if progression is documented 2
Catheter-Associated Phlebitis
Remove the peripheral catheter immediately if it is no longer needed. 1, 2
- For PICC-associated phlebitis, catheter removal is optional if anticoagulation is provided and symptoms improve 2
- If catheter-related chemical/mechanical phlebitis without thrombosis, conservative management with catheter removal and symptomatic treatment suffices—do not anticoagulate 3
Septic Phlebitis
Initiate prompt removal of the intravenous device, empiric antibiotics covering Staphylococcus aureus (41% of cases) and Group A streptococcus (20% of cases), heat application, and limb elevation. 4
- If clinical deterioration occurs or septicemia persists after 24 hours despite conservative therapy, perform operative excision of the involved vein 4
- Eighty percent of causative organisms are gram-positive bacteria 4
Adjunctive Non-Anticoagulant Therapies
All patients with phlebitis should receive:
- Graduated compression stockings (30-40 mm Hg) to reduce post-thrombotic symptoms 2
- Warm compresses applied locally to the affected area 2
- NSAIDs for pain and inflammation control, avoiding use if platelet count <20,000-50,000/mcL or severe platelet dysfunction present 2, 3
- Early ambulation rather than bed rest to reduce DVT risk 2
- Limb elevation while at rest 2
Special Population Considerations
Pregnant Patients
Use prophylactic-dose LMWH throughout the remainder of pregnancy and for at least 6 weeks postpartum, as fondaparinux crosses the placenta and DOACs lack safety data in pregnancy. 2
- Avoid vitamin K antagonists (warfarin) due to embryopathy risk between 6-12 weeks' gestation 2
Cancer Patients
Apply the same anticoagulation regimen as for non-cancer patients, as cancer patients with SVT have comparable mortality and DVT/PE recurrence risks to those with overt DVT. 2
Patients with Renal Impairment
Assess renal function before prescribing fondaparinux (renally cleared); consider unfractionated heparin if significant renal dysfunction exists. 2
Patients with Thrombocytopenia
Avoid aspirin and NSAIDs if platelet count <20,000-50,000/mcL, and consider dose modification or withholding anticoagulation if platelets <25,000/mcL. 1, 2
Monitoring and Follow-Up
- Repeat ultrasound in 7-10 days if initially managed conservatively, if symptoms worsen, or if clinical concern for progression exists 2
- Monitor for extension into the deep venous system, which necessitates immediate escalation to therapeutic anticoagulation 2, 7
- Approximately 10% of patients with SVT develop thromboembolic complications at 3-month follow-up despite anticoagulation 2
Critical Pitfalls to Avoid
- Failing to perform ultrasound in all suspected SVT cases to exclude concurrent DVT (present in ~25% of cases) 2, 3
- Treating thrombophlebitis within 3 cm of the saphenofemoral junction with only prophylactic doses instead of therapeutic anticoagulation 2, 7
- Using treatment duration shorter than the evidence-based 45 days for SVT ≥5 cm 2
- Prescribing bed rest rather than encouraging early ambulation, which increases DVT risk 2
- Treating infusion thrombophlebitis with anticoagulation when catheter removal and conservative measures suffice 3
- Misclassifying the peroneal vein as superficial when it is actually part of the deep venous system requiring full therapeutic anticoagulation 7
Prevention Strategies for Catheter-Related Phlebitis
For patients requiring parenteral nutrition or prolonged IV therapy:
- Use midline catheters when peripheral therapy is expected for more than 6 days 1
- Choose the smallest gauge catheter possible (ideally, catheter diameter should be one-third or less of vein diameter) 1
- Prefer polyurethane or silicone catheters over Teflon cannulas 1
- Ensure appropriate osmolarity of infused solutions and pH between 5 and 9 1
- Replace short peripheral venous catheters every 72-96 hours in adults to reduce phlebitis risk 1
- Evaluate catheter insertion site daily by palpation through dressing to detect tenderness 1