The most common cause of embolism is ?

RRB Nsg. Superintendent-21 July 2019 (Shift-2nd)

Pathology & Genetics

Easy

Appeared in: RRB Nsg. Superintendent-21 July 2019 (Shift-2nd)

Explanation

An embolus is a detached intravascular mass that travels through the bloodstream and obstructs a vessel.
Emboli originating from a thrombus (blood clot) are specifically called thromboemboli.
Thromboembolism is the most frequent type, accounting for over 90% of all cases of embolism.
The most common source of these emboli is deep vein thrombosis (DVT) in the deep veins of the lower legs, which can travel to the lungs causing a pulmonary embolism.

Option B: Air embolism is a rare event. It requires a significant amount of air (e.g., 100-150 mL) to enter the circulation to cause a fatal outcome, which is much less common than the formation of a thrombus.
Option C: Atheroembolism, caused by the rupture of atherosclerotic plaques, is a recognized cause of embolism but is significantly less common than thromboembolism.
Option D: Embolism from bone fragments is extremely rare. More commonly, severe trauma to long bones can cause fat and bone marrow embolism, but this is still far less frequent than thromboembolism.

Visual 1: Diagram - Illustrating the formation of a thrombus in a deep vein of the leg, a piece breaking off to become an embolus, and its journey to the lungs to cause a pulmonary embolism.
Visual 2: Infographic - Comparing the different types of emboli (thrombus, fat, air, atheromatous) with their common sources and clinical significance.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Etiology and Types of Embolism as background academic context rather than a clinical decision trigger.
Nurses play a crucial role in preventing thromboembolism by assessing for Deep Vein Thrombosis (DVT) in at-risk patients, such as those who are post-operative, immobile, or have a history of clotting disorders.
Key nursing interventions include encouraging early ambulation, applying compression stockings or sequential compression devices (SCDs), and administering anticoagulant medications as prescribed.
What if? - If a patient has a known patent foramen ovale (a hole between the heart's atria), a venous embolus from a DVT could cross into the arterial circulation (a paradoxical embolism) and cause a stroke instead of a pulmonary embolism, changing the clinical presentation entirely.

How to Approach the Question

This is a factual recall question that asks for the 'most common' cause of a condition.
First, define the key term: 'Embolism' is a blockage in a blood vessel caused by a traveling mass (embolus).
Next, review the options, which are all potential types of emboli.
Recall or deduce the relative frequency of each type. A thrombus (blood clot) is a very common pathological finding, especially in veins (DVT), which is a major risk factor for embolism.
Compare this with the other options, which are associated with more specific and less frequent events (e.g., major trauma for bone/fat, diving for air, advanced atherosclerosis for debris).
Conclude that a thrombus is the most prevalent source of emboli, making it the correct answer.

Concept Tested & Keywords

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