ABSTRACT
Pulmonary thromboembolism should not be regarded as a pulmonary disease; rather, it is a complication of underlying blood clots that were already formed in the venous system. With few exceptions, almost all emboli arise within the large deep veins of the pelvis and lower extremities (i.e.. popliteal, femoral, or iliac veins,5 Figure 9-1). Thrombus almost always starts in the veins of the calf and propagates to veins above the knee in 87% of the cases of DVT.5-7 Over 90% of pulmonary emboli arise from thrombi within popliteal, femoral, and iliac veins.5-7 This pathologic process creates a dilemma for clinicians and prehospital providers because most DVTs are clinically silent (i.e., remain undetectable on physical exam). DVTs and pulmonary emboli can only be detected with specific radiological tests.
