Health Professionals

Phlebitis Pitfalls

Superficial vein thrombophlebitis may occur spontaneously or as a
complication of medical or surgical interventions. Sterile thrombophlebitis
limited to the superficial veins rarely is life threatening, but a thorough
diagnostic evaluation is mandatory because many patients with superficial
phlebitis also have occult deep vein thrombosis (DVT), which carries very high rates of morbidity and mortality.

Phlebitis should be assumed to involve the deep veins until proven otherwise, because superficial vein thrombophlebitis and deep vein thrombophlebitis share the same pathophysiology, pathogenesis, and risk factors.

Superficial thrombophlebitis often progresses through perforating veins to involve the adjacent deep veins. In the case of spontaneous thrombophlebitis, a superficial phlebitis at one location may be accompanied by occult deep vein thrombosis in noncontiguous veins in the same leg or even in the contralateral leg. This occurs because hypercoagulable states tend to produce thrombosis simultaneously at multiple sites in both the superficial and deep venous systems. A surprising number of patients with clinically apparent superficial phlebitis subsequently die from a pulmonary embolism (PE). Autopsy studies in these patients have demonstrated that the site of deep vein thrombosis often is not contiguous with the site of superficial phlebitis.

Clinical examination alone cannot distinguish purely superficial
thrombophlebitis from phlebitis that has both superficial and deep vein
components. Duplex ultrasound identifies deep vein thrombosis in
approximately 30% of patients with obvious superficial thrombophlebitis who have no clinical evidence of deep system involvement, and continued surveillance reveals occult deep vein extension in 45% of cases. In hospitalised patients with superficial phlebitis, 10% eventually have a recognized diagnosis of PE, and 20% of those PEs are fatal. Every effort should be made to prevent superficial phlebitis from progressing to involve the deep veins, because damage to deep vein valves leads to chronic deep venous insufficiency (postphlebitic syndrome) as well as to recurrent PE and a risk of death.

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Lab Tests

• D-dimer
  A positive D-dimer is an indication for further investigation, but a negative D-dimer is not sensitive enough to change the course of evaluation or treatment for patients with suspected SVT, DVT or PE.
  
  
• Thrombophilia screen
  Several common hypercoagulable states can be identified through laboratory studies. Activated protein C resistance (most often due to factor V Leiden),Protein C deficiency, Protein S deficiency, Antithrombin III deficiency, Antiphospholipid antibodies,Lupus anticoagulant These tests should be ordered for every patient with phlebitis. They can have an impact on the short-term and long-term treatment plan and the frequency of follow-up examinations.
  
  
• Ultrasound
  Duplex ultrasound is the initial diagnostic study of choice for most patients with signs and symptoms of phlebitis. Duplex examination should not be limited to just one leg.
  
  Unfortunately, duplex ultrasound is not perfectly sensitive and after DVT has been excluded by ultrasound examination, patients should be monitored carefully with serial examinations until the phlebitis is resolved. Disease that initially involves only the superficial veins may progress over time to involve the deep system.
  
  
• V/Q scan
  Because ultrasound can miss DVT, all patients with superficial
  phlebitis who also have chest symptoms (such as pain, shortness of breath, or cough) should have a chest x-ray and ventilation-perfusion (V/Q) scan or high-resolution contrast CT scan of the chest, even if a duplex examination fails to reveal deep vein thrombosis.

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Treatment
Superficial phlebitis not involving the greater saphenous vein above the knee, without known risk factors and with no prior thromboembolic history: NSAID gradient compression stocking, increased ambulation,and early repeat examination.

Patients who have a prior history of deep thrombophlebitis, or known
irreversible risk factors for venous thrombosis, or with decreased mobility:
Outpatient treatment with full-dose anticoagulation using subcutaneous
low-molecular-weight heparin (LMWH). NSAID, gradient compression stocking,increased ambulation, and early repeat examination are also essential.

The most aggressive treatment is necessary for patients with superficial
phlebitis involving the greater saphenous vein above the knee, because greater saphenous phlebitis often ascends to pass through the saphenofemoral junction at the groin and into the deep venous system:
These patients are treated as outpatients with full-dose anticoagulation using subcutaneous LMWH. NSAID, graduated compression stocking,increased ambulation, and early repeat examination are also essential.

In the past, surgical interruption of the saphenofemoral junction
was recommended for patients with greater saphenous phlebitis approaching the saphenofemoral junction. Local transcatheter fibrinolysis provides an important alternative to this surgical approach.

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Important points to remember
Attempting to diagnose superficial thrombophlebitis and rule out DVT
on clinical grounds that are known to be unreliable-a duplex ultrasound scan is mandatory

Patients should be warned that superficial phlebitis can progress
to the deep veins and that any change in symptoms warrants immediate re-evaluation

DVT below the knee must be taken as seriously as more proximal DVT.

Always suspect a PE when a patient has chest symptoms in the
presence of leg symptoms (even when duplex scan of leg is normal).

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Resource: emedicine