PE/DVT

Question 1

Sources of Emboli?

Answer 1

pelvic veins
upper extremity veins
DVT in legs (90%)

Question 2

Non blod clot emboli sources?

Answer 2

Air
Tumor
Amniotic fluid
Talc
Fat

Question 3

Virchow’s Triad

Answer 3

Stasis
Hypercoagulability
Endothelial injury

Question 4

6 congenital causes of hypercoagulability?

Answer 4

Factor V Leiden mutation***
Prothrombin "G" mutation 
Protein C  & Protein S deficiency
Antithrombin III deficiency
Dysfibrinogenemia 
Homocystinemia

Question 5

9 acquired causes of hypercoagulability?

4 more important

Answer 5

estrogen*
pregnancy (hormonal)*
malignancy*
nephrotic syndrome*
thrombocytosis
DIC
HIT
antiphospholipid antibody syndrome
PNH

Question 6

4+ DVT risk factors are associated with a confirmed DVT rate of ___%;
3 risk factors&raquo_space; ___%
0 risk factors&raquo_space; ___%

Answer 6

100
50
11

Question 7

What factors determine the extent of physiologic consequences of PE?

Answer 7

The size of the embolus
Cardiopulmonary status/reserve
Neurohormonal substances

Question 8

Compensation by the circulation (due to PE)?

How does this help?

Answer 8

Vasodilatation of uninvolved vasculature –>

• helps to decrease pulm vasc resistance
• improves V/Q in uninvolved areas
• improves overall oxygenation

Question 9

What are the physiologic consequences of PE?

Answer 9

1. increased pulm vasc resistance
2. impaired gas exchange
3. alveolar hyperventilation
4. increased airway resistance (bronchoconstriction)
5. decreased pulm compliance

Question 10

What causes increase in pulm vasc resistance in PE?

Answer 10

1. Vascular obstruction

2. Neurohumoral agents (serotonin, Endothelin)

Question 11

What causes impaired gas exchange in PE?

Answer 11

1. Increased alv dead space from vasc obstr (V/Q mismatch)
2. Impaired carbon monoxide transfer (low DLCO) due to loss of gas exchange surface
3. Right-to-left shunting (in massive PE)

Question 12

What causes alveolar hyperventilation in PE?

Answer 12

reflex stimulation of irritant receptors

Question 13

What are possible causes of decreased pulm compliance in PE?

Answer 13

lung edema, lung hemorrhage or loss of surfactant

Question 14

Gas exchange abnormalities resulting from PE?

Answer 14

hypocapnia
hypoxemia
widened A-a gradient

Question 15

What causes tachypnea associated with PE?

Answer 15

increased minute ventilation

Question 16

What causes hypoxia associated with PE?

Answer 16

V/Q mismatch

shunting (if massive PE)

Question 17

What are the consequences, in terms of circulation + cardiac symptoms, of PE? (6)

Answer 17

Tachycardia
Decrease in cardiac output
Systemic hypotension
Pulmonary hypertension and cor pulmonale
Pulmonary infarction
Bradycardia (sometimes)

Question 18

Diagnostic Measures for PE

Answer 18

Clinical signs and symptoms
Laboratory data (ABG/BNP/Troponin)
EKG
CXR
V/Q Scan
Pulmonary angiography
Helical CT (CT Pulmonary angiography)

Question 19

What happens to the clot (micro path) following PE? Which is most favorable?

Answer 19

1. Fibrinolyis (most favorable outcome)
2. Organization of clot
3. Partial resolution /compensation via opening of arterial, collateral circ, increased alv ventil

Question 20

Common signs and symptoms in PE

Answer 20

dyspnea
pleuritic CP
tachypnea
tachycardia
loud P2

(increase HR/RR; decrease CO2/O2)

Question 21

Abn lab data in PE?

Answer 21

Widened A-a gradient
Nml or elevated WBC
elevated d-dimer
elevated LDH and bilirubin

Question 22

EKG findings in PE

Answer 22

Nonspecific ST-T abnormalities
Tachycardia
S1Q3T3 – found in a minority of patients***
Atrial arrhythmias

Question 23

Chest Radiography in PE (8)

What’s most common?

Answer 23

Normal CXR (most common)
Cardiomegaly
Hampton’s hump
Westermark’s sign
Sausage sign
Discoid atelectasis 
Elevated diaphragm
Pleural effusion (small when present)

Question 24

Do we need to learn Well’s criteria?

Answer 24

Previous DVT or PE  
Immobil/ Surg with in 4 weeks
Tachy HR > 100  per minute 
Cancer 
Hemoptysis 
Edema/Symp of DVT 
Diagnosis other than PE less likely

Question 25

Why is Lung Scan Interpretation combined with Clinical Assessment ?

Answer 25

high clinical suspicion + high prob V/Q scan = confirms PE

low + low = excludes

Question 26

V/Q Scanning - Pitfalls: (4)

Answer 26

1. 15 sec breath hold to complete test!
2. Better results in patients w/o structural disease
3. 30% observer variability
4. Majority of the scans are indeterminate

Question 27

What is the “gold standard test” for PE? How will a PE look on this test?

Answer 27

Pulmonary angiography

• filling defect
• cutoff sign

Question 28

What can establish or exclude the diagnosis of DVT?

Answer 28

Serial noninvasive studies (ultrasound)

Question 29

Primary diagnostic modality of choice for PE?

Answer 29

helical CT

Note: If a PE is excluded: provides alternate diagnosis in about 70% of patients

Question 30

Clinical manifestations of DVT

Answer 30

Swelling of the leg		
Duskiness
Homan’s sign - 50:50
Palpable deep thrombi
Dilated superficial veins (collaterals)
Tender cord in the femoral triangle

Question 31

Diagnostic Measures for DVT

Answer 31

Ascending contrast venography (invasive)

Real-time (B-mode) ultrasonography (US) ***

Question 32

Prevention of DVT (Prophylaxis)
normal patients?
sedated/sick?

Answer 32

Early mobilization

if sedated or sick:

1. TED hose stockings
2. Intermittent external pneumatic compression of the calf and thigh
3. anti-coags

Question 33

How are PE treated?

Answer 33

1. thrombolysis (tPA)
2. radiological intervention (clot disrupted w catheter or embolectomy)
3. surgical (Pulm embolectomy, thromboendarterectomy)

Question 34

Prognosis, if PE treated?

Answer 34

1. death = uncommon
2. pulm hemodynamics return to nml in 2-8 weeks
3. very fe develop pulm HTN

Question 35

“triad” associated with fat embolism?

Answer 35

Mental status changes
Thrombocytopenia
Petechiae in the chest and neck