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Flashcards in PE/DVT Deck (35):
1

Sources of Emboli?

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

2

Non blod clot emboli sources?

Air
Tumor
Amniotic fluid
Talc
Fat

3

Virchow’s Triad

Stasis
Hypercoagulability
Endothelial injury

4

6 congenital causes of hypercoagulability?

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

5

9 acquired causes of hypercoagulability?
(4 more important)

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

6

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

100
50
11

7

What factors determine the extent of physiologic consequences of PE?

The size of the embolus
Cardiopulmonary status/reserve
Neurohormonal substances

8

Compensation by the circulation (due to PE)?
How does this help?

Vasodilatation of uninvolved vasculature -->
-helps to decrease pulm vasc resistance
-improves V/Q in uninvolved areas
-improves overall oxygenation

9

What are the physiologic consequences of PE?

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

10

What causes increase in pulm vasc resistance in PE?

1. Vascular obstruction
2. Neurohumoral agents (serotonin, Endothelin)

11

What causes impaired gas exchange in PE?

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)

12

What causes alveolar hyperventilation in PE?

reflex stimulation of irritant receptors

13

What are possible causes of decreased pulm compliance in PE?

lung edema, lung hemorrhage or loss of surfactant

14

Gas exchange abnormalities resulting from PE?

hypocapnia
hypoxemia
widened A-a gradient

15

What causes tachypnea associated with PE?

increased minute ventilation

16

What causes hypoxia associated with PE?

V/Q mismatch
shunting (if massive PE)

17

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

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

18

Diagnostic Measures for PE

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

19

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

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

20

Common signs and symptoms in PE

dyspnea
pleuritic CP
tachypnea
tachycardia
loud P2

(increase HR/RR; decrease CO2/O2)

21

Abn lab data in PE?

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

22

EKG findings in PE

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

23

Chest Radiography in PE (8)
(What's most common?)

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

24

Do we need to learn Well's criteria?

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

25

Why is Lung Scan Interpretation combined with Clinical Assessment ?

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

(low + low = excludes)

26

V/Q Scanning - Pitfalls: (4)

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

27

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

Pulmonary angiography

-filling defect
-cutoff sign

28

What can establish or exclude the diagnosis of DVT?

Serial noninvasive studies (ultrasound)

29

Primary diagnostic modality of choice for PE?

helical CT

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

30

Clinical manifestations of DVT

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

31

Diagnostic Measures for DVT

Ascending contrast venography (invasive)
Real-time (B-mode) ultrasonography (US) ***

32

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

Early mobilization

if sedated or sick:
1. TED hose stockings
2. Intermittent external pneumatic compression of the calf and thigh
3. anti-coags

33

How are PE treated?

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

34

Prognosis, if PE treated?

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

35

"triad" associated with fat embolism?

Mental status changes
Thrombocytopenia
Petechiae in the chest and neck