Vascular disease and lower limb ischaemia Flashcards
Most common cause
Athersclerotic disease in lower limb arteries
Ischaemia
Perfusion fails to meet demands of tissues, tissue hypoxia and anaerobic metabolism result > tissue damage
Chronic ischaemia
Gradual process caused by atherosclerosis
Acute ischaemia
Sudden loss of perfusion of limb (occlusive thrombus/embolus)
Athersclerosis
- Endothelial damage
- Attracts monocytes > macrophages
- Attracts platelets > pro-inflammatory mediators
- Smooth muscle cells growth
- LDL rapidly oxidised > ox-LDL scavenged by macrophages > foam cells
- Foam cells die > lipid released into plaque
- Remain stable if inflammation resolve
Benefits of statins
- Lipid lowering
- Antiplatelet activity
- Stabilise plaques
Risk factors for athersclerosis
Smoking, hypertension, hyperlipidaemia, genetic predisposition, male, diabetes
Where does atherosclerosis happen
Large and medium size conduit artery, turbulence of blood flow at bifurcation
Chronic limb ischaemia
Bilateral, collateral circulation develops, eventually becomes critically ischaemic
Classification of limb ischaemia
- Asymptomatic
- Intermittent claudication
- Ischaemic rest pain
- Ulceration/gangrene (critical)
Signs of critical ischaemia
Foot pain at rest, gangrene, ulceration
Dry gangrene
Tissue necrosis without infection, minimal blood supply, toes usually first
Wet gangrene
Tissue necrosis and infection > sepsis and death
Cause of acute limb ischaemia
Atherosclerotic plaque rupturing > complete occlusion by thrombus/gives rise to embolus travels until gets stuck
Acute ischaemic 6 Ps
Painful Pulseless Perishingly cold Pallor Paraesthesia Paralysis
