Pulmonary Embolism Lecture Powerpoint

Question 1

Pulmonary embolism definition

Answer 1

Obstruction of pulmonary artery or one of its branches caused by a thrombus (clot, air, sickled cells, fat, tumor, infection, etc.)

Question 2

3 patterns of PE presentation and 2 severities of PE

Answer 2

• Acute immediately after obstruction
• subacute days or weeks after initial event
• Chronic with signs and symptoms of pulmonary hypertension over years
• Massive (high risk, unstable, characterized by the degree of hemodynamic compromise rather than size of obstruction)
• Submassive (intermediate risk, stable)

Question 3

Saddle PE

Answer 3

Occurs when an embolism lodges at bifurcation of main pulmonary trunk artery, relatively rare occurring phenomenon that if occludes blood flow to both pulmonary arteries can be life threatening

Question 4

PE is the ____ most common cause of unexpected death in most age groups, and the ___ most common cause of CV death in the US. Approx ___% of patients whom acute PE is diagnosed die within the first 60 min. ___% of patients in med ICU are at risk for DVT, and ___% of asymptomatic patients after coronary bypass graft are

Answer 4

1st or 2nd, 3rd, 10, 33, 50

Question 5

Lobar PE

Answer 5

Defined as a PE occurring either unilaterally or bilaterally in a pulmonary artery branch to a certain lobe of lung

Question 6

Patients who survive an acute PE are at high risk for 3 conditions

Answer 6

• recurrent PE
• pulmonary hypertension
• Chronic cor pulmonale (right sided heart failure in 70% of patients)

Question 7

3 components of virchow’s triad

Answer 7

• Hypercoagulable state (cancers, coagulopathy, estrogen therapy)
• Venous stasis (prolonged immobility)
• Injury/inflammation to vessel wall (fracture, surgery)

Question 8

More common places for PE to arise from in the body (4)

Answer 8

• thigh (common)
• calf (argued not to need as severe treatment)
• right heart (right ventricular thrombus is very bad)
• upper limbs (axillary or subclavian veins)

Question 9

Common symptoms of pulmonary embolism (5)

Answer 9

• Dyspnea at rest or upon exertion
• pleuritic chest pain
• cough
• calf pain or swelling (only about half)
• tachypnea

Question 10

Patients who do not present with 2 of these 3 major symptoms are unlikely to have a PE because 97% of patients with PE have some combo of these symptoms (the classic big 3 symptoms of DVT)

Answer 10

• dyspnea
• pleuritic chest pain
• tachypnea

Question 11

Massive PE classification

Answer 11

-sees a systolic BP <90mmHg or systolic blood pressure drop >40mmHg for baseline of >15 min, has high mortality rate within first hour of care

Question 12

Submassive PE classification

Answer 12

-Sees a systolic BP >90, very commonly seen (96% of PE) mortality less than 5%

Question 13

Gold standard for diagnosis of DVT as well as most common one used

Answer 13

Contrast venography, doppler ultrasonography (less sensitive below knees)

Question 14

Post phlebitic syndrome

Answer 14

A condition that manifests as leg pain, edema, stasis pigmentation, induration and ulceration that frequently resembles PE despite usually occurring usually within 2 years after DVT, can be minimized by use of compression stockings

Question 15

Labs for PE diagnosis (6)

Answer 15

• D dimer (good at ruling out PE but not in)
• EKG (right heart strain, right bundle branch block)
• Troponin I levels (indicates poor prognosis)
• ABG
• CBC
• BMP/CMP (need to get GFR for possible contrast administration)

Question 16

Imaging studies for PE diagnosis (3) and which is the most beneficial?

Answer 16

• CXR (rule out other causes)
• CT pulmonary angiography (most beneficial)
• VQ scan (choice for pregnant women who can’t get CT)

Question 17

Westermark sign

Answer 17

Seen on a chest x ray where there is dilation of pulmonary vessels proximal to embolism along with collapse of distal vessels with sharp cutoff

Question 18

Modified Well’s criteria for PE

Answer 18

Checklist to determine risk of PE using scoring system

Question 19

If patient has allergy to contrast and cannot undergo CT when evaluating PE, then the next best test is…

Answer 19

….VQ scan

Question 20

PE treatment (5)

Answer 20

• Initially assess hemodynamic stability and stabilize patient
• anticoagulation
• fibrolytic agents (for hemodynamically unstable patients to improve acute cor pulmonale
• vena cava filters
• Embolectomy

Question 21

Heparin requires monitoring of…

Answer 21

…PTT at a value of 1.5-2x control (60-70 sec –>120-140 sec) (remember aPTT is more sensitive and should be 30-40 sec)

Question 22

LMWH can be given ____ at a DVT prophylaxis dosage or post PE treatment for patients and _____ require PTT monitoring

Answer 22

SubQ, does not

Question 23

Only 2 direct oral anticoagulants used for monotherapy for stabilized PE

Answer 23

-Rivaroxaban (Xarelto) and apixaban (eliquis)

Question 24

Rivaroxaban and apixaban have ___ doses and ____ doses

Answer 24

loading, maintenance

Question 25

Common medicolegal pitfalls (3)

Answer 25

• dismissing complaints of unexplained SOB
• failure to recognize seriousness of DVT in below a knee
• Dismissing unexplained chest pain as musculoskeletal without adequate workup

Question 26

Pathway of the left and right pulmonary arteries

Answer 26

Left: travels anterior to the aorta forming the ligamentum arteriosum with it at its descending portion then hits the left bronchus
Right: Wraps under the aorta and then posteriorally horizontally across the mediastinum behind the superior vena cava before hitting the right bronchus

Question 27

CT Pulmonary angiography steps

Answer 27

• Inject contrast into pulmonary artery branch after percutaneous catheterization via femoral vein
• Rapid CT imaging (typically spiral/helical) of pulmonary vasculature follows

Question 28

Conventional vs spiral/helical CT

Answer 28

Conventional takes slices, the spiral/helical continuously taking slices so less is missed in the interspaces between slices.