Deep Venous Thrombosis 1. DVT most commonly manifests as pain and swelling. The physical exam may reveal tenderness, a difference in leg circumference, redness, and a positive Homan's sign. None of these signs or symptoms is specific, and DVT may also be completely asymp tomatic. Venography is an invasive procedure, and the contrast material can cause chemical phlebitis.
Venography is useful when the results of other studies are equivocal.
When clinical findings are inconsistent with Doppler studies, venography is necessary. Impedance plethysmography is an alternative technique for DVT diagnosis. Venous return in the lower extremity is occluded by in flation of a thigh cuff, and then the cuff is released, resulting in a decrease in calf blood volume. B. Pulmonary Embolism 1. Pulmonary embolism most frequently presents with dyspnea and tachypnea.