ÎUse one of the following initial tests:
• A highly sensitive D-dimer OR • Proximal CUS OR • Whole-leg US, rather than ▶ no testing (1-B for all comparisons) or ▶ venography (1-B for all comparisons). Whole-leg US may be preferred in patients unable to return for serial testing and those with severe symptoms consistent with calf DVT.
ÎConsider initial use of a highly sensitive D-dimer rather than US (2-C).
The choice between a highly sensitive D-dimer test or US as the initial test will depend on local availability, access to testing, costs of testing, and the probability of obtaining a negative D-dimer result if DVT is not present.
ÎIf the highly sensitive D-dimer is negative, no further testing is preferred over further investigation with proximal CUS or whole-leg US or venography (1-B for all comparisons).
ÎIf the highly sensitive D-dimer is positive, use proximal CUS or whole- leg US rather than no testing (1-B for all comparisons) or venography (1-B for all comparisons).
ÎIf proximal CUS is chosen as the initial test and is negative,
• repeat proximal CUS in 1 week or • test with a moderate or highly sensitive D-dimer assay rather than omit further testing (1-C) or venography (2-B).
ÎIn patients with a negative proximal CUS but a positive D-dimer, repeat proximal CUS in 1 week rather than omit further testing (1-B) or venography (2-B).
ÎIn patients with negative serial proximal CUS or a negative single proximal CUS and negative moderate or highly sensitive D-dimer, no further testing is preferred over further testing with whole-leg US or venography (1-B for all comparisons).
ÎIf whole-leg US is negative, no further testing is preferred over repeat US in 1 week or D-dimer testing or venography (1-B for all comparisons).
ÎIf proximal CUS is positive, treat for DVT rather than confirm with venography (1-B).
ÎIf isolated distal DVT is detected on whole-leg US, use serial testing to rule out proximal extension rather than proceeding to treatment (2-C).
▶ Patients with severe symptoms and risk factors for extension are more likely to benefit from treatment rather than repeat US. (See Kearon C. et al. CHEST 2012; 141(2)(Suppl):e418S–e494S.)
▶ Patients who place a high value on avoiding the inconvenience of repeat testing and a low value on avoiding treatment of false positive results are more likely to choose treatment over repeat US.
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