Risk factors of pulm embolism
**Core Concept**
Pulmonary embolism (PE) is a life-threatening condition where a blood clot dislodges from the deep veins of the legs and travels to the lungs, causing blockage of one or more pulmonary arteries. The risk factors for PE can be categorized into modifiable and non-modifiable factors, which play a crucial role in the development and progression of the disease.
**Why the Correct Answer is Right**
The correct answer is related to the Virchow's triad, which is a fundamental concept in understanding the pathophysiology of PE. Virchow's triad consists of three primary factors that contribute to the development of thrombosis: blood flow alterations, blood composition changes, and endothelial injury. In the context of PE, blood flow alterations and endothelial injury are significant risk factors. Blood flow alterations can occur due to immobility, surgery, or trauma, which can cause stasis of blood and lead to clot formation. Endothelial injury can result from various conditions, such as cancer, infection, or inflammation, which can damage the endothelial lining of blood vessels and increase the risk of clot formation.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because obesity is a risk factor for PE, but it is not the primary factor being considered in the context of Virchow's triad.
**Option B:** This option is incorrect because smoking is a risk factor for many cardiovascular diseases, but it is not a direct risk factor for PE in the context of Virchow's triad.
**Option C:** This option is incorrect because diabetes mellitus is a risk factor for many cardiovascular diseases, but it is not a direct risk factor for PE in the context of Virchow's triad.
**Clinical Pearl / High-Yield Fact**
It is essential to remember that the risk of PE is increased in patients with a history of recent surgery, trauma, or immobility, as these conditions can cause blood flow alterations and endothelial injury, leading to clot formation. A mnemonic to remember the risk factors for PE is "DASH": DVT (deep vein thrombosis), Age, Surgery, and Hospitalization.
**Correct Answer:** C.