Deep vein thrombosis: serial impedance plethysmography is useful in ruling out DVT.

Clinical bottom line (level 1b)

  1. A third of patients with suspected deep vein thrombosis had it.
  2. Impedance plethysmography performed at 1, 5 and 10 days after initial presentation with suspected DVT may help diagnose (LR+27) or rule it out (LR-0) .
Huisman et al: New England Journal of Medicine 1986; 314 (13): 823-828
Expires May 2004

The study

Setting: university hospital, Holland

426 patients (aged range 19 to 95 years; mean 62, 50% male) clinically suspected acute deep vein thrombosis, referred by their GPs

Excluded if
  • on anticoagulation
  • not available for 10 days study period



    • Independent blinded reference standard, applied in all patients from a consecutive appropriate spectrum.
    Reference standard:
    • venogram or follow-up for three to six months
    Diagnostic test: impedance plethysmography performed at 1, 5 and 10 days after initial presentation

    The evidence

    pre-test probability of deep vein thrombosis: 95%, (95% CI: 25% to 34%)

    differential diagnosis number of patients prevalence
    (95% CI)
    unknown 87 25%
    (20% to 29%)
    twisting injury to leg 38 11%
    (7.6% to 14%)
    cellulitis 31 8.9%
    (5.9% to 12%)
    muscle tear/strain 24 6.9%
    (4.2% to 9.5%)
    superficial phlebitis 17 4.9%
    (2.6% to 7.1%)
    Baker's cyst 7 2.0%
    (0.50% to 3.5%)
    other 38 11%
    (7.6% to 14%)


    diagnostic test deep vein thrombosis no deep vein thrombosis LR+
    (95% CI)    		 post-test probability LR-
    (95% CI)    		 post-test probability
    impedance plethysmography 126 11 27
    (15 to 49)     		92% 0.0
    (0.0 to 0.024)     		0%
    total 137 289

    Citation

    1. Huisman MV, Buller HR, Ten Cate JW, et al: Serial impedance plethysmography for suspected deep venous thrombosis in outpatients. The Amsterdam General Practitioner Study. New England Journal of Medicine 1986; 314 (13): 823-828
    Contributor: Chris Ball and Clare Wotton, May 2000
    Reviewer:

    Clinical Question.
    Patient suspected acute DVT
    Intervention or Exposure impedance plethysmography
    Comparison venogram
    Outcome diagnosis