Week 6

Question 1

Where do lower extremity DVT’s most commonly originate?

Answer 1

calf veins at the valve leaflets

may extend proximally into calf and thigh

Question 2

What are the signs and symptoms of lower extremity DVT?

Answer 2

lower extremity swelling and pain (unilateral)

swelling more likely cardiovascular in origin and secondary to heart failure

Question 3

What’s the pathophysiology of Virchow’s triad?

Answer 3

Venous stasis- more time for clotting, small clots not washed away, inc blood viscosity
Vessel wall damage- accidental/surgical trauma
Blood coagulability increase- inc in tissue factor, presence of activated factors, dec in coag inhibitors

Question 4

What are 3 hyper-viscosity syndromes?

Answer 4

heparin induced thrombocytopenia (platelet deficiency)
myelodysplasia (cancer of immature bone marrow blood cells)
polycythemia (too many RBC in bone marrow)

Question 5

The Homan’s sign is a reliable diagnostic tool for DVT. True or false

Answer 5

False

can be positive w/ other conditions such as gastrocnemius tears

Question 6

Palpable cords are an unreliable sign of DVT. True or false

Answer 6

True

often found in patients with SVT instead of DVT

Question 7

Accuracy of clinical diagnosis of DVT is

Answer 7

50%

Question 8

Wells score:

Answer 8

estimation of probability of DVT prior to ordering an ultrasound
based on clinical risk factors

Question 9

What are the positive criteria of the Wells score

Answer 9

\+1 point for each
active malignancy (within 6wks)
paralysis, paresis or recent plaster immobilization of lower limb
bedridden >3days
major surgery/trauma within past 4 wks
localized tenderness along lower extremity veins 
swelling of entire lower limb
pitting edema
swelling greater than 3cm

Question 10

In the wells score, calf swelling greater than ____ as compared to asymptomatic leg yields a point.

Answer 10

3cm

Question 11

Peripheral edema:

Answer 11

seen in both legs

can be due to aging of the veins, or other conditions that put pressure on the leg veins

Question 12

Wells score negative criteria:

Answer 12

-2 points for DDx as likely as DVT

Question 13

Wells score final totals:

Answer 13

probability of DVT:
high >3 points
intermediate 1-2 points
low <0

Question 14

What are the most common means of measuring pretest probability for DVT?

Answer 14

d-dimer

Wells score

Question 15

If there is a low pretest probability and a negative d-dimer test, what treatment is necessary?

Answer 15

none

Question 16

In patients with a high pretest probability for PE or DVT, the D-dimer assay should not be obtained since the negative predictive value of the assay is low. True or false

Answer 16

true

Question 17

Patients can be treated on the basis of a + d-dimer test test alone. True or false

Answer 17

false

Question 18

What increases the pulsatility of the Doppler waveform in the EIV and CFV?

Answer 18

tricuspid valve regurgitation or rt. sided heart failure

Question 19

Thrombus in the _____ _____ or ____ will flatten the Doppler signal and eliminate respiratory variation and cardiac pulsations in the CFV and below.

Answer 19

EIV and IVC

Question 20

What can also eliminate/reduce the respiratory variation in veins below the inguinal ligament?

Answer 20

compression by pelvic or inguinal masses

ascites

Question 21

What is the gold standard for US evaluation of DVT?

Answer 21

compression

Question 22

What is primary diagnostic criterion for DVT?

Answer 22

lack of venous compression or complete coaptation of walls
intraluminal echoes
color void-complete or partial
lack of spontaneous flow
absence of respiratory variation
high sensitivity for thigh DVT
low sensitivity for calf thrombus

Question 23

What is the best way to treat DVT? (not really a great question but it was a bullet point lol)

Answer 23

prevention!

Question 24

The part of Virchow’s triad with the greatest impact is venous stasis. What do we use to keep blood flowing?

Answer 24

calf venomotor pump

can also elevate the lower extremity to aid gravity

Question 25

What do compression stockings do?

Answer 25

keep the vein at a smaller diameter, pushing blood upward and not allowing it to pool into stasis dermatitis precursor to venous ulcers

Question 26

What is the medical treatment for DVT?

Answer 26

anticoagulants - initially heparin injection, then oral drug started within 24-48h

Question 27

Inadequate anticoagulation in the first _________ may increase risk of recurrence or PE.

Answer 27

24 to 48hrs

Question 28

Acute DVT can be treated on an outpatient basis unless:

Answer 28

``` severe symptoms require parental analgesic other disorders preclude safe outpatient discharge other factors (functional, socioeconomic) that prevent the patient from adhering to prescribe treatments ```

Question 29

What's the goal for DVT treatment? (primary and secondary)

Answer 29

primary- PE prevention | secondary- symptom relief, prevention of DVT recurrence, chronic venous insufficiency and postphlebitic syndrome

Question 30

Are treatment of upper and lower DVT the same?

Answer 30

yes, generally

Question 31

Which anticoagulant is taken orally? Which one is injected?

Answer 31

oral- warfarin, factor Xa or direct thrombin inhibitor | injected- heparin

Question 32

Warfarin is also known as?

Answer 32

coumadin

Question 33

What anticoagulants are most often used?

Answer 33

``` low molecular weight heparins (LMWHs) unfractionated heparin (UFH) fondaparinuv warfarin non-warfarin oral anticoagulants (factor Xa inhibitors, apixaban. Direct thrombin inhibitors- dabigatran) ```

Question 34

An IVC filter may help prevent PE in patients with:

Answer 34

``` LEDVT who have contraindications to anticoagulant therapy recurrent DVT (despite adequate anticoagulation) ```

Question 35

Where is an IVCF placed?

Answer 35

in IVC just below renal veins, via catheterization of IJV or FV

Question 36

What are some complications of the IVCF?

Answer 36

migration tilts/shifts fractures perforation

Question 37

Thrombectomy:

Answer 37

includes percutaneous mechanical thrombectomy and pharamalogical thrombolysis most invasive and used prior to new methods

Question 38

With percutaneous mechanical thrombectomy, the thrombus can be mechanically removed via

Answer 38

a catheter inserted into the CFV it macerates the thrombus and suctions it away. Uses medicines that prevent clot formation

Question 39

Streptokinase, urokinase and alteplase lyse clots, and may be more effective to prevent postphlebitic syndrome than heparin alone, but

Answer 39

the risk of bleeding is higher than with heparin

Question 40

Thrombolytic therapy alone may be indicated for

Answer 40

large proximal thrombi | those in iliofemoral veins, and for phlegmasia alba or cerulea dolens

Question 41

Historically, if DVT's persisted a patient would have to do surgical bypass reconstruction. What do they do now instead? Why?

Answer 41

Balloon dilations and stents | less invasive

Question 42

Where do they feed the venous balloon dilation catheter

Answer 42

vein near the groin

Question 43

Duration of treatment is typically

Answer 43

3-6mo depending on presence and nature of risk factors some people may need lifelong treatment

Question 44

What are some early preventative measures for DVT?

Answer 44

early mobilization, leg elevation, compression stockings/devices/both and anticoagulants (required for bedbound patients w/ major illness or those undergoing certain surgical procedures)