Mod 2-5 Pulmonary Embolism

Question 1

Pulmonary embolism is a potentially ________ condition.

Answer 1

fatal

Question 2

What is the most common pathologic process involving the lungs of hospital patients?

Answer 2

Pulmonary embolism

Question 3

Pulmonary embolism is the ____ most common cause of death in hospitalized patients. How many annually?

Answer 3

third; 650,000

Question 4

Approximately what percentage of patients have died in the hospital had pulmonary embolism? Of those, what percentage had missed diagnosis?

Answer 4

60%; 70%

Question 5

What is the definition of an embolus?

Answer 5

intravascular mass that may be composed of air, fat or solid material that is carried by the blood to a site other than its origin.

Question 6

Over ___% of emboli begin as a thrombus.

Answer 6

98%

Question 7

What is a thrombus?

Answer 7

A blood clot that becomes an embolus when it moves through the circulation.

Question 8

What does an emboli of arterial origin usually affect?

Answer 8

The legs or brain or other organ in the body and usually causes an infarction (tissue death).

Question 9

What does an emboli of venous origin usually affect?

Answer 9

Lungs and may or may not cause pulmonary infarction.

Question 10

Where does most emboli arise from?

Answer 10

Deep veins of a lower extremity site (calf or thigh) where blood platelets have attached to a venous valve.

Question 11

What four things encourage the development of deep vein thrombosis in the lower extremity?

Answer 11

1) Venous stasis from bed rest or during a major operation.
2) Injury to the inner lining of a vein.
3) Hyperclotting state
4) Previous embolus

Question 12

Why are elderly patients particularly subject to pulmonary embolus?

Answer 12

1) Reduced activity levels caused by a number of reason such as conditions that require extended amounts of bedrest or surgery creating predisposition to embolus.
2) Some cancer cells may produce agents that increase the formation of clots.
3) They have experienced a MI or a stroke and have had a previous clot which predisposes another clot.

Question 13

What percentage of PE’s arise in the deep vein of the legs?

Answer 13

95%

Question 14

As a clot detaches itself from a venous site, where does it pass through?

Answer 14

Passes through inferior vena cava, right atrium, right ventricle, main pulmonary artery, right or left lung until it can no longer go further.

Question 15

What percentage of clots are of such a large size that they will occlude the pulmonary artery itself or lodge where ether artery bifurcates?

Answer 15

5%

Question 16

Describe the vast majority of emboli.

Answer 16

Small and accompanying symptoms are very hard to diagnose.

Question 17

What sites may be affected by PE?

Answer 17

• Major pulmonary artery or site of bifurcation artery (5%/)

- More distal arterial sites (up to 80%)

Question 18

Symptoms of PE are easily diagnosed from clinical symptoms and are specific. T/F?

Answer 18

False

*Not easily diagnosed and symptoms are often vague and non-specific.

Question 19

Clinical manifestations are absent or inconclusive in about ___% of patients.

Answer 19

80%

Question 20

What is the classical clinical appearance of PE?

Answer 20

Cough with hemoptysis (blood), dyspnea and pleuritic chest pain.
*Hemoptysis occurs only in the minority of patients.

Question 21

What percentage of patients display classic clinical manifestations of PE?

Answer 21

20%

Question 22

Why is it that older patients may not have chest pain?

Answer 22

Because of altered pain sensation or it may be mistaken for pain of angina.

Question 23

Cough is present in less than ___% of patients.

Answer 23

50%

*But is non-specific and attributed to any number of chest problems from TB to respiratory allergies.

Question 24

What are some clinical signs of PE?

Answer 24

Palpitations, increased heart rate, wheezing, cyanosis, elevated temperature.

Question 25

What percentage of chest radiographs of those with PE are read as normal?

Answer 25

15%

Question 26

What are some examples of radiographic evidence that may support a clinical suspicion of PE?

Answer 26

1) Focal oligemia (deficiency of blood in the body or any organ and lucency or involved lung portion)
2) Enlargement of ipsilateral main pulmonary artery caused by distention created by the thrombus.
3) PE with infarction appears as consolidation. (Hamptoms Hump is highly characteristic, but uncommon. Usually at base of the lung in the costophernic sulcus. May simulate pneumonia or atelectasis).
4) Small pleural effusion

Question 27

What is focal oligemia?

Answer 27

A deficiency in the amount of blood in the body or any organ and lucency of involved portion of the lung.

Question 28

Where is Hamptom’s Hump seen? What does it simulate?

Answer 28

At the base of the lung in the costophrenic sulcus. Simulates pneumonia or atelectasis.

Question 29

After a chest x-ray, what exam would follow to screen for a PE?

Answer 29

Lung perfusion scan in nuclear medicine.

Question 30

What is a problem with lung scans in nuc med? And what is done to fix this?

Answer 30

There are false positive findings. High resolution CT or arteriography may be used to provide conclusive evidence.

Question 31

After a lung scan in nuclear medicine, what exam is done to provide conclusive evidence?

Answer 31

A high resolution CT or arteriography.

*Both can provide conclusive evidence of the presence or absence of a clot.

Question 32

What can provide conclusive evidence of the presence or absence of a clot?

Answer 32

Computed tomography of the chest or pulmonary angiography.

Question 33

What affects does PE have on radiographic technique?

Answer 33

None

*Patient may be anxious, SOB