Mod10: Orthopedic surgery - Thromboembolic Event DVT & PE

Question 1

_{Orthopedic surgery - Thromboembolic Event - DVT & PE}

Which different substances could cause a PE?

Answer 1

Fat - Air (VAE) - Blod clot - Aminiotic fluid - CO2

Question 2

_{Orthopedic surgery - Thromboembolic Event - DVT & PE}

Pathogenesis of DVT & PE:

Answer 2

Venous stasis

Hypercoagulable state

Vascular damage

_{DVT and PE can cause morbidity and mortality following orthopedic operations on the pelvis and LEs - but know that DVTs and PEs can occur after any surgery and during any hospitalization}

Question 3

_{Orthopedic surgery - DVT & PE - Pathogenesis}

How does venous stasis leads to Venous thrombosis?

Answer 3

Venous thrombosis associated with

Venous stasis - Hypercoagulable states - Vascular damage

Surgery leads to all of three of these

Question 4

_{Orthopedic surgery - DVT & PE - Pathogenesis}

Venous stasis is associated with which conditions:

Answer 4

pregnancy,

abdominal tumors,

varicose veins, or

conditions with vascular damage, such as vasculitis

Question 5

_{Orthopedic surgery - DVT & PE - Pathogenesis}

Conditions that create a hypercoagulable state:

Answer 5

inflammatory conditions (for example sepsis), CAD, DM, malignancy, nephritic syndrome, prolonged bedrest, and localized and systemic inflammatory responses to surgery

Question 6

_{Orthopedic surgery - DVT & PE - Pathogenesis}

Patients with which CV conditions are at increased risk for arterial thrombosis?

Answer 6

artificial heart valves, a fib, certain valvular heart conditions

Question 7

_{Orthopedic surgery - DVT & PE - Pathogenesis}

Factors associated with DVT and PE:

Answer 7

(see picture from M&M)

Others not listed might include:

hx of previous DVT,

oral contraceptive use,

severe infection,

previous miscarriage,

pregnancy, CAD

(by Barash)

Question 8

_{Orthopedic surgery - DVT & PE}

Greatest risk for DVT occurs with which surgeries?

Answer 8

hip surgeries,

knee arthroplasties, and

any other major operation

Question 9

_{Orthopedic surgery - DVT & PE}

Incidence of DVT in patients undergoing at risk surgeries who do not receive any sort of prophylaxis

Answer 9

40-80%

Question 10

_{Orthopedic surgery - DVT & PE}

The incidence of clinically significant PEs can be as high as

Answer 10

20%, as reported by some studies

Question 11

_{Orthopedic surgery - DVT & PE}

The incidence of fatal PEs is between

Answer 11

1 and 3%

Question 12

_{Orthopedic surgery - Thromboembolic Event - Pulmonary Embolus}

Concern with Pulmonary emboli:

Answer 12

Pulmonary emboli obstruct blood vessels, increasing overall resistance to blood flow thru the pulmonary vascular system

Question 13

_{Orthopedic surgery - Thromboembolic Event - Pulmonary Embolus}

Common forms and sources of emboli:

Answer 13

Common forms of emboli are blood clots, such as from a DVT

Other sources or forms of emboli are amniotic fluid, air, CO2 and fat, as we discussed earlier

Question 14

_{Orthopedic surgery - Thromboembolic Event - Pulmonary Embolus}

Clinical Manifestations or symptoms:

Answer 14

Dyspnea

Tachypnea

Chest pain

Hemoptysis

^{(implies lung infarction)}

Symptoms usually absent or mild AND nonspecific unless massive embolism has occurred

Question 15

_{Orthopedic surgery - Thromboembolic Event - Pulmonary Embolus}

Pulmonary signs of PE include:

Answer 15

Audible wheezing with auscultation

ABG will show mild hypoxemia with respiratory alkalosis (alkalosis secondary to hyperventilation)

Question 16

_{Orthopedic surgery - Thromboembolic Event - Pulmonary Embolus}

Cardiac signs of PE:

Answer 16

Tachycardia

Wide fixed splitting of the S2 heart sound

Hypotension with elevated CVP => indicates RV failure

Question 17

_{Orthopedic surgery - Thromboembolic Event - Pulmonary Embolus}

CXR findings with a PE:

Answer 17

CXR may be normal, or

Show an area of focal oligemia (reduction in blood flow)

Such area will appear as a radiolucency (transparent to radiation or x-rays; recall that radiolucent structures appear more black, where as radiopaque materials appear as white)

In the CXR attached, look in R lung base, you can see it appears blacker than the rest of the lungs, which appear to have a bit more opacity than the focal area with oligemia): this will be seen distal to the PE

Others possible findings on CXR include wedge-shaped density with an infarct, atelectasis with an elevated diaphragm, asymmetrically enlarged proximal pulmonary artery with acute pulmonary HTN

Question 18

_{Orthopedic surgery - Thromboembolic Event - Pulmonary Embolus}

Diagnosis of PE:

Answer 18

Gold standard for Dx is pulmonary angiography but this is invasive and difficult to perform

Spiral CT is preferred method for initial images in stable patients with suspected PE

If CTA not available, V/Q scanning can be performed

Question 19

_{Orthopedic surgery - Thromboembolic Event - Pulmonary Embolus}

How do PE present under Anesthesia?

Answer 19

Significant PEs rarely occur during anesthesia AND They are difficult to diagnose under anesthesia

Usually presents as sudden CV collapse, hypoxemia or bronchospasm

You will also see Decreased in EtCO2, but this is not specific

Question 20

_{Orthopedic surgery - Thromboembolic Event - Pulmonary Embolus}

Management of intra-op PE:

Answer 20

Ensure adequate O2 & ventilation

Hemodynamic support

Anticoagulation and thrombolytic therapies

IVC filter

Pulmonary embolectomy

Question 21

_{Orthopedic surgery - Pulmonary Embolus - Management of intra-op PE}

Ensure adequate O2 & ventilation; how?

Answer 21

100% O2

Establish airway

Monitor ABG

^{Management as far as supportive measures is going to be similar to what we have already discussed with VAEs – ensure oxygenation, ventilation and hemodynamic support.}

^{What will be different if it is a blood clot will be the specific measures to manage a clot, versus the measures taken to manage an embolus of another form}

Question 22

_{Orthopedic surgery - Pulmonary Embolus - Management of intra-op PE}

Anticoagulation and thrombolytic therapies:

Answer 22

With blood clots systemic anticoagulation will be initiated to prevent the formation of any new clots. This will also prevent the extension of existing clots

Heparin

^{Heparin therapy provided in order to maintain the PTT at about two times the normal level}

Warfarin

^{For patients to go home on an oral warfarin regimen, they will need to be on both heparin and warfarin at the same time for about 4-5 days}

^{The INR should be therapeutic for two consecutive measurements, at least 24 hours apart – before stopping the heparin}

Thrombolytic therapy

^{Thrombolytic therapy, such as with TPA or streptokinase, should be started in patients with massive thrombotic PEs or circulatory collapse}

Question 23

_{Orthopedic surgery - Pulmonary Embolus - Management of intra-op PE}

Contraindications to Thrombolytic therapy:

Answer 23

Contraindications for anticoagulation and thrombolytic therapies include recent surgery and active bleeding

In these patients, an IVC filter may be placed to prevent recurrence

Question 24

_{Orthopedic surgery - Pulmonary Embolus - Management of intra-op PE}

Appropriate Tx option for patients who have a massive PE and in whom thrombolytic therapy is contraindicated:

Answer 24

Removing the clot surgically via

Pulmonary embolectomy

Question 25

_{Orthopedic surgery - Pulmonary Embolus}

Antithrombotic Prophylaxis

^{Best treatment for PE is:}

Answer 25

PREVENTION

Question 26

_{Orthopedic surgery - Pulmonary Embolus}

Antithrombotic Prophylaxis

^{Besides prevention, what else is recommended?}

Answer 26

Anticoagulants

Antiplatelets

Dextran therapy

Early ambulation

Intermittent pneumatic compression devices

High elastic stockings

Question 27

_{Orthopedic surgery - Pulmonary Embolus}

Anticoagulants use for Antithrombotic Prophylaxis:

Answer 27

Heparin

^{(for example: unfractionated heparin 5000 units SQ q 12 started pre-op or immediately postop)}

Enoxaparin/Lovenox

^{(Lovenox) or other related compounds}

Warfarin/Coumadin

^{Oral anticoagulation (warfarin)}

Fondaparinux/Arixtra

Direct thrombin inhibitors

Question 28

_{Orthopedic surgery - Pulmonary Embolus}

Antiplatelets use for Antithrombotic Prophylaxis

Answer 28

ASA

ADP receptor antagonists

^{(clopidogrel/Plavix, ticlopidine/Ticlid)}

Glycoprotein IIb/IIIa antagonists

^{(abciximab/Reapro, eptifibatide/Integrilin, tirofiban/Aggrastat)}

Dipyridamole/Persatine

Question 29

_{Orthopedic surgery - Pulmonary Embolus - Antithrombotic Prophylaxis}

Early ambulation

^{How can we facilitated this?}

Answer 29

We can help with this by making sure out patient’s pain is under control

You want your patients to wake up comfortably!

It will help set the stage for a smooth post op period

Question 30

_{Orthopedic surgery - Pulmonary Embolus - Antithrombotic Prophylaxis}

Compression devices and stockings

^{benefits in preventing PE:}

Answer 30

May decrease risk of venous thrombosis in lower extremities but…

Do nothing for clot formation in heart or pelvis