Pulmonary Embolism Flashcards
What is a blood clot that forms and remains in a vein called?
A thrombus
What is a blood clot that becomes dislodged and travels to another part of the body?
Embolus
What can happen if an embolus significantly disrupts pulmonary blood flow?
Pulmonary infarction develops and causes atelectasis, consolidation and tissue necrosis
Although the precise mechanism is not known, how does an embolism cause bronchoconstriction?
The embolism causes the release of cellular mediators such as seratonin, histamine, and prostaglandins from platelets
What is a saddle embolus?
A fatal condition in which a large embolus is lodged in the bifurcation of the pulmonary artery
What are the pathologic and structural changes of the lungs associated with pulmonary embolism?
Blockage of the pulmonary vascular system, pulmonary infarction, alveolar atelectasis, alveolar consolidation, bronchial smooth muscle constriction
Approximately, how many cases of pulmonary embolism is reported each year in the US?
650,000
About how many Americans die annually from Pulmonary Embolism?
50,000
What are some possible sources of pulmonary embolism?
Fat, air, amniotic fluid, bone marrow, tumor fragments
Where do most pulmonary blood clots originate or break from?
Sites of Deep Venous Thrombosus (DVT); lower parts of the body
What is Virchow’s triad?
Three primary factors associated with the formation of DVT; venous stasis, hypercoagulation, and injury to the endothelial cells that line the vessels
What are some diagnostic procedures used to diagnose a suspected pulmonary embolism?
Chest X-Ray Film, Spiral (Helical) Computed Tomography Scan, Electrocardiogram, Ventilation-Perfusion Scan, and Pulmonary Angiogram
Which diagnostic procedure can be used to rule out conditions that mimic PE?
Chest x ray film
Which diagnostic procedure can provide a three-dimensional image of any abnormalities with a high degree of accuracy?
Spiral (helical) computed tomography scan
Which diagnostic procedure is is excellent for ruling out pericarditis and myocardial infarction?
Electrocardiogram
Which diagnostic procedure often raises more questions than it answers?
Ventilation-perfusion scan
Which diagnostic procedure is extremely accurate for diagnosis of PE, but is invasive, time consuming and requires a high degree of skill to administer?
Pulmonary angiogram
Inactivity, CHF, varicose veins, and thrombophlebitis are examples of what type of risk factors for PE?
Venous stasis
What are some common surgical procedures associated with PE?
Hip, pelvic, knee, and certain obstetric or gynecologic procedures
Bone fractures, extensive injury to soft tissue, postoperative or postpartum states, extensive honor abdominal operations, and phlegmasia alba dolens puerperarum are examples of what kind of risk factors associated with PE?
Trauma
What are some hypercoagulation disorders commonly associated with PE?
Oral contraceptives, polycythemia, and multiple myeloma
What are some tests used to detect venous thromboembolism (VTE)?
D-diner blood test, duplex venous ultrasonography, extremity venography, magnetic resonance imaging, magnetic resonance angiography, and blood tests
Which test is used to check for an increased level of the protein fibrinogen?
D-diner blood test
What values for results in the d-dimer blood test are considered positive?
D-dimer values higher than 500 ng/mL
Which test uses high-frequency sound waves to detect blood clots in the thigh veins?
Duplex venous ultrasonography
Which test is used to differentiate between blood, thromboemboli, and tumor emboli in patients with malignancy?
Magnetic resonance angiography
Why are fast-acting anticoagulants used as general management of PE?
They are given to prevent existing blood clots from growing and to prevent the formation of new ones
Enoxaparin, dalteparin, and tinzaparin are examples of what kind of drug?
Low-molecular-weight heparin
What other drug is typically given following fast-acting anticoagulants such as heparin?
Warfarin (Coumadin, panwarfarin)
What do fibrinolytic agents (or thrombokytic agents) do?
Dissolve blood clots
Streptokinase, urokinase, alteplase and reteplase medications examples of?
Thrombolytic agents
What are some preventative measures suggested for patients at high risk of thromboembolic diseases?
Walking, exercise while seated, drink fluids, and graduated compression stockings
How may vasoconstriction be induced in PE?
Humoral agents and alveolar hypoxia
How does the release of humoral agents cause vasoconstriction?
These agents induce smooth muscle constriction of the tracheobronchial tree and the pulmonary vascular system, reducing cross-sectional area
How does alveolar hypoxia cause vasoconstriction in PE?
Humoral agents causes bronchoconstriction, and V/Q ratio and the PaO2 decline. Pulmonary Vasoconstriction is the compensatory mechanism.
