PVD - intermittent claudication and critical limb ischaemia Flashcards
What is intermittent claudication?
Most often refers to cramping pains in the buttock or leg muscles, especially the calves which occurs after walking for a given distance or walking uphill. The pain is relieved by rest
Pain is almost always in the calf, whatever level of obstruction, but may extend into the thigh
What would calf claudication indicate in terms of disease site?
Femoral disease
What would buttock claudication indicate in terms of disease site?
Iliac disease
What are the risk factors for peripheral vascular disease?
Major (GASD)
- Gender - Male
- Aging
- Smoking
- Diabetes mellitus
Other
- Hypercholesterolaemia
- Hypertension
- Obesity
What is peripheral vascular disease?
Occurs due to atherosclerosis causing stenosis or arteries via a multifactorial process involving modifiable and non-modifiable risk factors
What are the most commonly affected vessels in PVD?
Those of the lower limbs
What is the pathophysiology of claudication?
Decreased blood flow to peripheral tissue leads to tissue ischaemia. These leads to a variety of outcomes, one of which is the release of adenosine, leads to the perception of pain
What would thigh claudication indicate in terms of disease location?
Iliac or Common femoral artery
What would pain in the lower 1/3rd of the calf indicate in terms of disease location?
Popliteal artery
What would claudication in the foot indicate in terms of disease location?
Tibial or peroneal artery
What are the signs/symptoms of peripheral vascular disease?
- Intermittent claudication
- Ulceration
- Skin colour changes - elevated pallor, dependant rubor
What is regarded as stage one PVD as per the Fontane classification system?
Asymptomatic disease
What is stage 2 peripheral vascular disease as per the Fontane classification system?
Intermittent claudication
What are the characteristics of stage 3 PVD as per the Fontane classification system?
Rest pain/nocturnal pain
What are the characteristics of stage 4 PVD as per the Fontane classification system?
Necrosis/gangrene
What physical signs are associated with someone suffering from intermittent claudication?
Absent/reduced pulses - dorsalis pedis, posterior tibial and popliteal inevitably absent
Trophic changes at this stage are rare, although there may be more systemic signs of vascular disease
What is Buerger’s sign?
In patients with suspected vascular disease, when the patient lies on their back with a leg elevated for at least a few minutes, the foot becomes white; the patient is then quickly sat upright with legs hanging down and the limb turns dark red.
What is the mechanism behind buergers sign?
Partial or total occlusion of the arteries of the leg by emboli or thrombosis leads to limited vascular flow to the distal leg and foot.
Raising the leg further worsens arterial blood flow to the limb, causing the foot to become white. When the foot is then placed close to the ground, gravity assists flow to the distal limb and, along with compensatory peripheral vasodilatation (in response to poor perfusion), the leg quickly turns red.
What does a positive buerger’s sign indicate?
A positive Buerger’s sign (loss of pallor and spreading redness on dependency) indicates severe limb-threatening ischaemia and should be treated immediately.
What is the definition of critical limb ischaemia?
Persistently recurring rest pain requiring regular analgesia for > 2 weeks, or ulceration or gangrene affecting the foot, plus an ankle systolic pressure of <50 mmHg
What is ABPI?
Ankle-Brachial Pressure Index
The ratio of the blood pressure at the ankle to the blood pressure in the upper arm (brachium). Compared to the arm, lower blood pressure in the leg is an indication of blocked arteries due to peripheral artery disease (PAD). The ABPI is calculated by dividing the systolic blood pressure at the ankle by the systolic blood pressure in the arm
What would an ABPI of > 1.2 indicate?
Calcified arteries
What would a normal ABPI score be?
0.9-1.2
What ABPI score would indicate intermittent claudication?
0.5-0.9
What would an ABPI of <0.5 indicate?
Critical limb ischaemia
What happens to ABPI readings when arteries are calcified?
Falsely increased