VTE Prophylaxis

Venous thromboembolism (VTE) includes deep vein thrombosis (DVT) and pulmonary embolism (PE). Prophylaxis reduces the chance that a clot will form; it does not treat an established clot and does not make VTE impossible. Hospitalization concentrates the three forces that promote thrombosis: venous stasis, endothelial injury, and hypercoagulability. Bed rest slows calf-muscle venous return. Surgery and vascular devices injure the endothelium. Cancer, pregnancy, the postpartum state, estrogen therapy, prior VTE, obesity, older age, and inherited thrombophilia increase the tendency of blood to clot. A patient may therefore have little risk from one factor alone but substantial risk when several occur together. Hospital-associated VTE is a major preventable harm. More than one-third of VTE cases diagnosed annually in the United States are associated with a recent hospitalization, and most of those events are not recognized until after discharge. Prophylaxis is therefore a time-limited reduction in risk during a vulnerable period, not a guarantee that the patient will remain protected at home. The decision is not “anticoagulate every admission.” The decision is whether this patient’s current thrombotic risk outweighs the harm of...