■ Score≥2 indicates a high pretest riskfor DVT.
■ D-dimer
■ Fibrin breakdown product
■ Indicates presence of a clot (somewhere) within past 72 hours
■ Elevated levels may be seen in sepsis, pregnancy, trauma, MI, liver
disease, cancer (and more).
■ ELISA (quantitative) is more accurate than latex agglutination (qualitative).
■ Duplex ultrasound=study of choice
■ Ultrasound with color Doppler flow evaluation
■ Highly sensitive for proximal DVT of leg, but
■ May not identify calf vein or iliac vein thrombosis
■ Venography:Gold standard, but rarely used (invasive, radiation, cost)
■ MRI
■ Highly sensitive for DVT
■ Useful for DVT in iliac vein or vena cava where ultrasound cannot be used
■ A clinical diagnosis is established using a combination of the above modal-
ities (see Table 2.29).TREATMENT
■ Immediate anticoagulation with LMW heparin
■ Requires dose adjustment in renal failure
■ Does not prevent investigation for hypercoagulable state
■ If heparin contraindicated (eg, heparin-induced thrombocytopenia),
use thrombin inhibitor, such as lepirudin or danoparoid.
■ Long-term anticoagulation:Warfarin, first dose in the ED
■ Thrombolysisisnotmore effective than heparin for preventing PE, but
■ May accelerate clot lysis and reduce complications of venous insuffi-
ciencyin massive thrombosis
■ Contraindications: As with myocardial infarction
■ IVF filter indications include:
■ Contraindication to or complication of anticoagulation (bleeding, heparin-
induced thrombocytopenia)
■ Propagation of DVT despite adequate anticoagulation with warfarin
and heparin
■ Presence of free-floating nonadherent iliofemoral thrombus >5 cm
■ Massive clot burden
■ Many possible clinical scenarios exist in the treatment of DVT (see Table 2.30).CARDIOVASCULAR EMERGENCIES
TABLE 2.29. Clinical Evaluation for Deep Venous ThrombosisLow or moderate pretest risk
If D-dimer normal →no DVT present.
If D-dimer elevated →obtain extremity ultrasound to exclude DVT.High pretest risk
Obtain extremity ultrasound to exclude DVT.
If ultrasound negative but D-dimer elevated →plan repeat ultrasound in 5—7 days.
If ultrasound and D-dimer both negative →no DVT present.Suspected pelvic vein or vena caval thrombosis
Obtain CT with contrast or MR venography.LMW heparin requires dose
adjustment in renal failure.Thrombolysis is notmore
effective than heparin for
preventing PE in DVT.D-dimer measured by ELISA is
more accurate than the latex
agglutination method.