# Diagnosis

Diagnosis

The most common presentation of  a DVT is pain and swelling, especially in the calf, usually in one leg; however, bilateral DVTs are common, occurring in up to 30%. When the swelling ) . - - 

Figure 62.31
An organised thrombus.

is bilateral, DVT must be di ff erentiated from other causes of systemic oedema, such as hypoproteinaemia, renal failure and heart failure. Some patients have no symptoms of  thrombosis and may first present with signs of  a pulmonary embolus, e.g. pleuritic chest pain, haemoptysis and shortness of breath. Patients may also develop shortness of  breath from chronic pulmonary hypertension. Sometimes the leg appears cellulitic and very occasionally it may be white or cyanosed: phlegmasia alba dolens and phlegmasia cerulea dolens ( Figure 62.32 indicates venous pressures that are so high they are impeding tissue perfusion. Patients who present with venous gangrene ( Figure 62.33 ) often have an underlying neoplasm. Clinical examination for DVT is unreliable. Physical signs may also be absent. Mild pitting oedema of  the ankle, dilated surface veins, a sti ff calf  and tenderness over the course of  the deep veins should be sought. Leg pain occurs in about 50% of patients with DVT but is non-specific. Homans’ sign – resistance John Homans , 1877–1957, Professor of  Clinical Surgery , Harvard University Medical School, Boston, MA, USA, a founding member of  the Society f Surgery . Philip Wells , contemporary , physician, University of  Ottawa, Ottawa, ON, Canada. specific and should not be elicited. Tenderness occurs in 75% of patients but is also found in 50% of  patients without objectively confirmed DVT . The pain and tenderness associa ted with DVT does not usually correlate with the size, location or extent of the thrombus. Clinical signs and symptoms of pulmonary embolus occur in about 10% of  patients with confirmed DVT . A low-grade pyrexia may be present, especially in a patient who is having repeated pulmonary embolus. Patients may have signs of  cyanosis, dyspnoea, raised neck veins , a fixed split sec - ond heart sound and a pleural rub if  they have pulmonary emboli causing right heart strain, although these signs may be subtle or absent. 

Figure 62.32
Phlegmasia cerulea dolens.
Figure 62.33
A foot with venous gangrene. The gangrene is symmet
rical, involving all of the toes. There is no clear-cut edge and there is
marked oedema of the foot.