S2: Ch1 Cv 3-1

Front 1

532. Acute Arterial Occlusion?

Back 1

a. Acute occlusion of an artery, usually caused by embolization. The common femoral artery is the most common site of occlusion. Less commonly, in situ thrombosis is the cause.

Front 2

533. Sources of emboli for acute arterial occlusion?

Back 2

a. Heart (85%)
i. AFib is the most common cause of embolus from the heart.
ii. Post-MI
iii. Endocarditis
iv. Myxoma
b. Aneurysms
c. Atheromatous plaque.

Front 3

534. Clinical features of acute arterial occlusion?

Back 3

a. Pain-acute onset. The pt can tell you precisely when and where it happened. The pain is very severe, and the pt may have to sit down or may fall to the ground.
b. Pallor
c. Polar (cold)
d. Paralysis
e. Paresthesias
f. Pulselessness (use Doppler to assess pulses)

Front 4

535. Diagnosis of acute arterial occlusion?

Back 4

a. Arteriogram to define site of occlusion
b. ECG to look for MI, AFib.
c. Echocardiogram for evaluation of valves, clot, MI.

Front 5

536. Tx of acute arterial occlusion?

Back 5

a. Main goal: assess viability of tissues to salvage the limb.
i. Skeletal muscle can tolerate 6 hours of ischaemia; perfusion should be re-established w/in this time frame.
ii. If paralysis or paresthesias are present, amputation is probably necessary.
b. Immediately anticoagulate w/IV heparin
c. Emergent surgical embolectomy is indicated via cutdown and Fogarty balloon. Bypass is reserved for embolectomy failure.
d. Tx any complications such as compartment syndrome that may occur.

Front 6

537. Review 1-3 on 52.

Back 6

537. Review 1-3 on 52.

Front 7

538. Cholesterol embolization syndrome?

Back 7

a. This syndrome is due to “showers” of cholesterol crystals originating from a proximal source (e.g., atherosclerotic plaque), most commonly the abdominal aorta, iliacs, and femoral arteries.
b. It is often triggered by a surgical or radiographic intervention (e.g., arteriogram), or by thrombolytic therapy.
c. It presents w/small, discrete areas of tissue ischaemia, resulting in blue/black toes, renal insufficiency, and/or abdominal pain or bleeding (the latter is due to intestinal hypoperfusion).

Front 8

539. Tx for cholesterol embolization syndrome?

Back 8

a. Supportive. Do not anticoagulate.
b. Control BP. Amputation or surgical resection is only needed in extreme cases.

Front 9

540. Mycotic Aneurysm?

Back 9

a. An aneurysm resulting from damage to the aortic wall secondary to infection.
b. Blood cultures are positive in most cases.

Front 10

541. Tx for mycotic aneurysms?

Back 10

a. IV ABX and surgical excision.

Front 11

542. Luetic Heart?

Back 11

a. Luetic heart is a complication of syphilitic aortitis, usually affecting men in their 4th or 5th decade of life.

Front 12

543. Tx of Luetic heart?

Back 12

a. IV PCN and surgical repair.

Front 13

544. Virchow’s Triad for DVT?

Back 13

1. Endothelial injury
2. Venous stasis
3. Hypercoagulability

Front 14

545. Risk factors for DVT?

Back 14

a. >60 yo
b. Malignancy
c. Prior hx of DVT, PE, or varicose veins
d. Hereditary hypercoagulable states (factor V Leiden, protein C and S deficiency, AT III deficiency.
e. Prolonged immobilization or bed rest.
f. Cardiac disease, especially CHF.
g. Obesity
h. Major surgery, especially surgery of the pelvis (orthopedic procedures)
i. Major trauma
j. Pregnancy, oestrogen use.

Front 15

546. Clinical features of DVT?

Back 15

a. Presentation may be subtle.

Front 16

547. Classic findings for DVT (all have very low sensitivity and specificity)?

Back 16

a. Lower-extremity pain and swelling (worse w/dependency/walking, better w/elevation/rest).
b. Homan’s sign (calf pain on ankle dorsiflexion)
c. Palpable cord
d. Fever

Front 17

548. Note: Only 50% of pts w/the classic DVT findings have a DBT, and only 50% of pts w/documented DVT have the classic findings.

Back 17

548. Note: Only 50% of pts w/the classic DVT findings have a DBT, and only 50% of pts w/documented DVT have the classic findings.

Front 18

549. Note: If a superficial venous system is patent, the classic findings of DVT (erythema, pain, cords) will not occur bc blood drains from these patent veins. This is why only ½ of all pts w/DVT have the classic findings.

Back 18

549. Note: If a superficial venous system is patent, the classic findings of DVT (erythema, pain, cords) will not occur bc blood drains from these patent veins. This is why only ½ of all pts w/DVT have the classic findings.

Front 19

550. 4 tests for diagnosing DVT?

Back 19

1. Doppler analysis and Duplex U/S.
2. Venography
3. Impedance plethysmography
4. D-Dimer testing

Front 20

551. Doppler analysis and Duplex U/S for DVT?

Back 20

a. Initial test for DVT; non-invasive, but highly operator-dependent.
b. High sensitivity and specificity for detecting proximal thrombi (popliteal and femoral).
c. Not so for distal (calf vein) thrombi).

Front 21

552. Most accurate test for DVT of calf veins?

Back 21

a. Venography

Front 22

553. Venography for DVT testing?

Back 22

a. Most accurate test for DVT of calf veins.
b. Invasive and infrequently used.
c. Allows visualization of the deep and superficial veins
d. Also allows for assessment of patency and valvular competence.

Front 23

554. Impedance plethysmography for DVT?

Back 23

a. A non-invasive alternative Doppler U/S.
b. Blood conducts electricity better than soft tissue, so electrical impedance decreases as blood volume increases.
c. High sensitivity for proximal DVT, but not for distal DVT (calf veins)
d. Poor specificity bc there is a high rate of false positives.
e. As accurate as Doppler, but less operator-dependent.

Front 24

555. D-dimer testing for DVT?

Back 24

a. Has a very high sensitivity (95%), but low specificity (50%)
b. Can be used to rule out DVT when combined w/Doppler and clinical suspicion.

Front 25

556. Interpretation of diagnostic tests for DVT- Intermediate-to-high pretest probability of DVT?

Back 25

a. If Doppler is positive, begin anticoagulation.
b. If Doppler is nondiagnostic, repeat U/S every 2-3 days for up to 2 wks.

Front 26

557. Interpretation of diagnostic tests for DVT- Low-tointermediate probability of DVT?

Back 26

a. If Doppler is negative, there is no need for anticoag, observation is sufficient.
b. Repeat U/S in 2 days.