Pulmonary Embolism Flashcards
Thrombus?
Blood clot
Embolism?
Blood clot (thrombus) or air/other things obstructing blood flow that mobilizes within vessels
Pulmonary embolism?
Thrombus in a pulmonary vessel (within he pulmonary circuit)
What is the mortality rate for PE?
> 30% mortality (if a large vessel is obstructed, death will occur very quickly)
Does pulmonary embolism go away after it is treateD?
Yes, but there is a high rate of recurrence
Etiology of pulmonary embolism
- Majority is d/t DVT
- Fat embolism from fracture
- Air embolism
- Amniotic fluid from ruptured amniotic sac
- saddle embolus
Which veins does a thrombus from a DVT typically occur in?
iliac, femoral, popliteal, great saphenous veins of the leg
Explain how DVT causes a PE
Thrombus within the iliac, femoral, popliteal, great saphenous veins of the leg that embolisms and reaches the pulmonary circuit.
Is a DVT life-threatening?
Not necessarily, it is only a major problem when the clot travels to a vital organ circulation
Explain the route of a thrombus if it were coming from the the lower body.
Into inferior vena cava -> R atrium -> R ventricle -> pulmonary artery -> pulmonary capillaries -> pulmonary vein (cloth gets caught in one of the smaller vessels of the pulmonary circuit)
Explain how a fracture causes pulmonary embolism
Fatty bone marrow is released during orthopaedic surgery or if a bone is fractured in trauma -> fat enters the circulation and moves as an emboli, reaching the pulmonary circuit
How does an Air embolism occur?
From syringe or tubing
How does amniotic fluid from a ruptured amniotic sac cause pulmonary embolism?
Amniotic fluid enters circulation during trauma or delivery through severed blood vessels.
Saddle embolus?
Named after the saddle-like appearance of an embolus created by a thrombus settling at the area where pulmonary vessels bifurcate, attracts platelets, causing the thrombus to increase in size
Explain the pathology of a pulmonary embolism. Assume that the P.E. was caused from a DVT.
DVT -> embolus -> R side of heart -> pulmonary circulation -> thrombus in arterial bed -> decreased perfusion ->. platelets attracted to the site of the thrombus d/t abnormality in vessel -> platelets degranulate to release mediators to attract more platelets but the degranulation also causes brachial and pulmonary artery constriction. There is hemodynamic instability d/t obstruction and further constriction of vessel and the nervous system reflexively causes bronchoconstriction. This results in a ventilation: perfusion imbalance (hypoxemia & systemic hypoxia). Decreased CO & decreased surfactant