Pulmonary Embolus Flashcards Preview

Gen Med Unit 6 > Pulmonary Embolus > Flashcards

Flashcards in Pulmonary Embolus Deck (24):
1

Define pulmonary embolus

1. Obstruction of pulmonary arterial bed by a dislodged thrombus or heart valve vegetation
2. Serious and potentially fatal condition

2

Where do PE's usually arise from?

1. Arise from:
A. Thrombus in venous circulation
B. Thrombus from right side of heart
2. >90% originate from clots in deep veins of lower extremities
3. Approx. 50-70% of symptomatic PE’s have LE DVT when diagnosed

3

Where else can PEs arise from?

1. Air embolus from central lines
2. Amniotic fluid from active labor
3. Fat embolus from femur fracture

4

what is Virchow's Triad? What are its components?

3 categories of factors that are thought to contribute to thrombosis:
A. Hypercoagulability
B. Hemodynamic changes (stasis, turbulence)
C. Endothelial injury/dysfunction

5

What risk factors are asst. with pulmonary embolism?

1. Surgical procedure
A. Ortho, pelvic, abdominal
2. Cancer
3. Oral contraceptives
4. Pregnancy
5. Bedrest (prolonged nonactivity)
6. Prior Hx DVT or PE

6

What causes a thrombus to dislodge?

1. Trauma
2. Intravascular pressure changes
3.Change in peripheral blood flow

7

What is the pathophys of PE?

1. Starts with (Virchow’s Triad):
Vascular wall damage
or Venostasis or Hypercoaguability
2. Thrombus dislodges

3. Embolus →right side of heart → pulmonary artery

4. Embolus occludes pulmonary arterial vessel

8

What happens when an embolus occludes the pulmonary arterial vessel?

1. Prevents alveoli from producing sufficient surfactant
2. Alveoli collapse
3. Atelectasis develops

9

What are the symptoms of PE?

1. Nonspecific
2. Pleuritic chest pain
3. Dyspnea
4. Apprehension
5. Cough
6. Hemoptysis

10

What are the signs of PE?

1. Tachycardia
2. Tachypnea
3. Rales
4. Low grade fever
5. ↓ PaO2
6. Loud S2
7. +/- LE edema
8. S3 or S4 gallop

11

What are the ABG results in PE?

Resp alkalosis secondary to hyperventilation

12

What are the EKG results in PE?

1. Sinus tachycardia
2. Non specific ST-T wave abnormalities
3. S1Q3T3
A. Seen in < 20% patients

13

What is the D-dimer test?

degradation product of fibrin

14

What are the D-dimer results in PE?

1. ↑ in presence of thrombus
2. Sensitivity 95-97%, specificity 45%
3. Can be used as a screen to R/O thrombosis
4. > 250 ng/mL D-Dimer Units (DDU)
5. > 0.5 mcg/mL Fibrinogen Equivalent Units (FEU)

15

What are the CXR results in PE?

1. May be normal (most commonly) or show non-specific abnormalities
A. Atelectasis
B. Prominent PA
C. Elevated hemidiaphragm
D. May show Hampton's hump

16

What is a ventilation/perfusion scan and when is it indicated?

1. Demonstrates perfusion defect with normal ventilation
2. Done if contraindication to CT contrast dye or CT not available

17

What is the initial test for identifying a PE?

Spiral CT, noninvasive

18

What is the definitive test for PE?

1. Pulmonary CT angiogram
A. Rarely used unless non-invasive testing leaves uncertainty of diagnosis

19

What are the treatment goals in PE?

1. Maintain adequate cardiovascular & pulm function during resolution of obstruction

2. Prevent recurrence of emboli

20

What are the anticoagulation treatment options for PE?

Recurrent PE requires life long anticoagulation

1. LMW heparin
A. Enoxaparin (Lovenox) SQ q 12h x 5+ days
B. Fondaparinux (Arixtra) SQ qd x 5+ days
C. Rivaroxaban (Xarelto) PO bid x 21 days
D. Dalteparin (Fragmin) SQ qd-bid x 5+ days
AND
2. Start warfarin (Coumadin) 2-10 mg qd
A. Maintain INR 2.0-3.0 (goal 2.5)

21

What are SpO2 goals for PE treatment?

Oxygen therapy to maintain SaO2 > 90%

22

What is Inferior IVC Filter? When is it indicated?

1. Indicated in patients who are at high risk of recurrence or when anticoagulants are a major contraindication
2. Filters blood returning to heart & lungs

23

What are the anticoagulation guidelines for PE?

1. 3 mo of anticoagulation after first episode provoked by surgery or a transient nonsurgical risk factor
2. 6-12 mo for unprovoked episode w/low to moderate risk of bleeding (3 mo if high risk of bleeding)

24

How is PE prevented in high risk pts?

1. For high risk patients:
A. Early ambulation
Intermittent pneumatic compression stockings
B. Low molecular weight heparin or low dose heparin