Vascular Flashcards
How can you distinguish between neurogenic and vascular claudication?
Intermittent vascular claudication should be differentiated from neurogenic
claudication, which can also present as pain in the lower limb on exertion. Neurogenic
What is intermittent claudication?
Intermittent claudication is defined as a reproducible discomfort of a defined group of
muscles that is induced by exercise and relieved with rest.
Usually described by the patient as a cramping, aching pain in the muscle group on exertion such as walking,
and alleviated on stopping (patient does not have to sit down for pain to go away) – “shop window to shop window”.
Defintion of critical limb ischaemia?
Critical limb ischaemia is defined as a decrease in limb perfusion that causes a potential threat to limb viability (manifested by a greater than 2 week history of ischemic rest pain, ulceration, and/or gangrene).
Ankle brachial pressure index is typically <0.5.
Defintion of critical limb ischaemia?
Critical limb ischaemia is defined as a decrease in limb perfusion that causes a potential threat to limb viability (manifested by a greater than 2 week history of ischemic rest pain, ulceration, and/or gangrene).
Ankle brachial pressure index is typically <0.5.
Difference between wet and dry gangrene?
Gangrene is cyanotic, anaesthetic tissue associated with or progressing to necrosis, which occurs when arterial blood supply falls below the threshold to meet minimal metabolic requirements.
Dry gangrene is hard and dry with a clear demarcation between viable and necrotic tissue. Can be allowed to auto-amputate.
Wet gangrene occurs in the presence of infection and is moist, swollen, frequently blistered. This requires surgical debridement or amputation.
What is LeRiche’s syndrome?
LeRiche’s syndrome arises from occlusion of the aortoiliac arteries, and is composed of:
Tetrad of buttock claudication, impotence in men, absent femoral pulses (and distal pulses), and occasionally presence of aortoiliac bruits.
What is the anatomical locations of the lower limb pulses?
Femoral pulse: Midpoint of the line joining the pubic symphysis to the anterior superior iliac spine (mid-inguinal point), just below the inguinal ligament
Posterior tibial pulse: one-third of the way down a line joining the medial malleolus to the heel
Dorsalis pedis pulse: just lateral to extensor tendon of hallux.
Popliteal pulse: Ask patient to bend the knee ~60 degrees, then palpate deeply in the popliteal fossa. [Suspect a popliteal aneurysm, if the pulse is strong.]
When is Burgers test significant?
A normal lower limb can be raised to 90 degrees without turning white; the lower the angle the greater the degree of peripheral vascular disease, if the Buerger’s angle is less than 20 degrees, this indicates severe ischaemia
How is ABPI measured?
Brachial pressure is measured with a blood pressure cuff around the arm and a Doppler probe over the brachial artery.
The cuff is inflated until the arterial signal is obliterated, then slowly deflated until the signal just starts being detected, at which the pressure is recorded.
Ankle pressures are measured in a similar manner, with the cuff around the calf and the Doppler at the dorsalis pedis and posterior tibial arteries, taking one reading for each artery.
The ankle pressure to be used for each leg is the
higher of the two taken. Ankle pressure is then divided by the brachial pressure, to calculate the ankle-brachial pressure index
What are the significant cut-off values for ABPI measurements?
> 1 Normal (or calcified vessels. e.g. diabetes)
0.5-1 Intermitted claudication
0.3-0.5 Rest pain/critical limb ischaemia
<0.3 Gangrene, ulceration
What are varicose veins?
Varicose veins are dilated tortuous superficial veins affecting the lower limb.
Most often found in distribution of the long saphenous vein (most common) and short saphenous vein
What causes varicose veins?
Inherent weakness in the vein wall, leading to dilation and separation of valve cusps so they become incompetent. This may be aggravated by obstruction to venous return (secondary varicosities)
What are some RFs for primary varicose veins?
What is secondary varicose veins?
- Age
- Parity
- Occupation – requiring long periods of standing
- Weight
- Increased abdominal pressure – constipation, chronic cough, etc
Varicose veins that develop after trauma or deep vein thrombosis are of secondary
cause
What is acute limb ischaemia?
Acute limb ischemia is defined as a sudden decrease in limb perfusion, that causes a potential threat to limb viability.
This is manifested by ischemic rest pain, ischemic
ulcers and gangrene, within two weeks of the acute event. (If >2 weeks it is considered chronic ischaemia).
Acute ischaemia is usually due to sudden occlusion of a feeding arterial vessel. It may occur in a setting of already narrowed vessel lumen (acute on chronic ischaemia) or in a normal lumen.
What are the 6 features of acute critical limb ischaemia?
Pain
Pallor
Pulselessness
Paraesthesiae
Paralysis
Perishing cold (poikilothermia)
In order of sensitivity to ischaemia, the tissues affected are nerves (most sensitive), muscle, and skin. So, early signs of ischaemia involve pain and numbness, with muscle paralysis and skin changes occurring much later.
The lower limb can survive about 6 to 8 hours in an ischaemic state before the injury becomes irreversible
Ix and mx for acute limb ischaemia?
