CHAPTER 61 ARTERIAL OCCLUSION

Question 1

Pain at rest, ulceration or gangrene exists

Answer 1

CRITICAL LIMB ISCHEMIA

Question 2

Most important risk factors for PAD

Answer 2

Smoking and DM

Others: hyperlipidemia, hypertension, elevated blood homocysteine, elevated CRP

Question 3

Most frequently diseased arteries

Answer 3

For The ABc

Femoropoplitieal
Tibial
Aortoiliac
Brachiocephalic

Question 4

Pathophysiology of Acute Limb Ischemia

Answer 4

Sudden decrease in blood supply to a limb –> tissue hypoperfusion and threatening limb viability

Question 5

Irreversible changes occurs within how many hours of vessel occlusion due to absence of collateral vessels

Answer 5

4 - 6 hours

Question 6

What can happen following restoration of blood flow

Answer 6

REPERFUSION INJURY
- compartment syndrome, rhabdomyolysis, metabolic derangements

Question 7

Most common cause of Acute Limb Ischemia

Answer 7

THROMBOTIC OCCLUSION

Question 8

Thrombotic occlusion in lower limbs

Answer 8

> 80%

Question 9

Thrombotic occlusion in upper limbs

Answer 9

half due to thrombosis
one third due to embolism

Question 10

Other than plaque rupture, progression of ischemic injury can occur by:

Answer 10

(1) propagation of clot to occlude collateral vessels,
(2) ischemia related distal edema leading to high compartment pressures (compartment syndrome),
(3) fragmentation of clot into the microcirculation, and
(4) edema of the microvasculature cells.

Question 11

Occlusion from embolism is MORE common than occlusion from thrombosis

Answer 11

FALSE

less common

Question 12

The __________ is the predominant source of peripheral emboli, with ___________________ being responsible for most cases.

Answer 12

heart; atrial fibrillation

Question 13

Noncardiac sources of arterial emboli

Answer 13

thrombi from aneurysms

atheromatous plaques

Question 14

Most common location where emboli lodges

Answer 14

1) Bifurcation of the common femoral artery
2) Popliteal artery

An embolus may fragment and embolize distally, or it may propagate locally and create a larger clot.

Question 15

Most commonly affected of embolism in the upper limb

Answer 15

Brachial artery

Question 16

Patients with acute limb ischemia exhibit one or more of the “six Ps”

Answer 16

pain
pallor
paralysis
pulselessness
paresthesias
poikilothermia (for cold)

Question 17

A lack of one or more of the 6Ps findings does not exclude ischemia

Answer 17

TRUE

Question 18

__________ alone may be the earliest symptom of ischemia, localized in the limb distal to the site of obstruction.

Answer 18

PAIN

Question 19

Skin changes

Answer 19

Pallor –> blotchy and mottled areas of cyanosis –> petechiae and blisters –> skin and fat necrosis (late)

Question 20

Painful cyanotic discoloration of isolated portion of foot; remainder of the foot is warm

Answer 20

Trash foot or blue toe syndrome

Question 21

Vasospasm in small arteries or arterioles provoked by cold or stressors;
Local pain, pallor, cyanosis, numbness, paresthesias in hands usually resolving in 30–60 min;
Rewarming, medications: calcium channel blockers, α-blockers, vasodilators

Answer 21

Raynaud’s disease

Question 22

Young Asian women: peripheral ischemia and necrosis leading to pulseless phase; may have fever, rash, muscle aches, arthritis

Answer 22

Takayasu’s arteritis

Question 23

Painful nodules, ulceration, and gangrenous digits in young adults (age 20–40 y);
Nonatherosclerotic segmental inflammation of small/medium vessels; typically, seen only in smokers

Answer 23

Thromboangiitis obliterans (Buerger’s disease)

Question 24

Painful discoloration of one or more ulnar fingers with sparing of thumb;
Repeated trauma to the hypothenar area with hammering in laborers, as well as those using vibrational tools, causing narrowing of ulnar artery or aneurysmal degeneration

Answer 24

Hypothenar hammer syndrome

Question 25

Thigh pain and numbness in cyclists and triathletes: measure pre- and postcycling ankle-brachial indexes

Answer 25

External iliac artery endofibrosis

Question 26

Criteria use of Acute limb ischemia

Answer 26

Rutherford Criteria

Question 27

Acute limb ischemia

Answer 27

symptoms starting within a 2-week
period
Pain over the distal forefoot waking the patient at night or requiring the patient to hang his or her feet over the bed

Question 28

Seen in chronic peripheral arterial disease

Answer 28

Claudication

Question 29

cramp-like pain, ache, or tiredness that is brought on by exercise and relieved by rest, similarly to angina in the heart;
reproducible, resolves within 2 to 5 minutes of rest, and recurs at consistent walking distances

Answer 29

Claudication

Question 30

Claudication site: Buttocks, thigh, and sometimes calf (if bilateral, may cause impotence in men)

Answer 30

Iliac artery

Question 31

Claudication site: Thigh

Answer 31

Common Femoral Artery

Question 32

Claudication site: Upper two-thirds of calf

Answer 32

Superficial femoral artery

Question 33

Claudication site: Lower one third of calf

Answer 33

Popliteal artery

Question 34

Claudication site: Foot

Answer 34

Infrapopliteal (tibial and peroneal) artery

Question 35

Hallmarks of chronic peripheral arterial disease

Answer 35

Shiny, hyperpigmented skin with hair loss and ulceration, muscle atrophy, and poor pulses

Question 36

Ratio of the systolic blood pressure with the cuff just above the malleolus (with the Doppler probe over the posterior tibial or dorsalis pedis artery) to the highest brachial pressure in either arm

Answer 36

ankle-brachial index

Question 37

ABI interpretation

Answer 37

Chronic <0.9
Severe <0.4
Noncompressible vessel >1.3

Question 38

initial therapy of choice in the ED

Answer 38

IV unfractionated heparin (weight-based 80 units/kg bolus followed by an infusion of 18 units/kg/h)
80-18