Arterial disease of the limbs/ critical limb ischaemia Flashcards
5 normal palpable pulses not including radial or brachial
aorta common femoral artery popliteal artery posterior tibial pulse dorsalis pedis pulse
What is Buerger’s disease
inflammation and thrombosis in small and medium-sized blood vessels, typically in the legs and leading to gangrene. It has been associated with smoking.
what is gangrene?
Gangrene is a serious condition where a loss of blood supply causes body tissue to die. It can affect any part of the body but typically starts in the toes, feet, fingers and hands. Gangrene can occur as a result of an injury, infection or a long-term condition that affects blood circulation.
risk factors for critical limb ischaemia (8)
Male Age Smoking Hypercholesterolemia Hypertension Diabetes Trauma Beurgers Disease
what is critical limb ischaemia
severe obstruction of the arteries which markedly reduces blood flow to the extremities (hands, feet, and legs) and has progressed to the point of severe pain and even skin ulcers or sores
Name, step by step, the progression of lesions from initial to complicated in atherosclerosis
initial lesion fatty streak intermediate lesion atheroma fibroatheroma complicated lesion
Stages of symptoms in CLI (4)
asymptomatic - incomplete occlusion of blood vessel
mild claudication pain in limb - when walking a distance less than/more than 200 metres
Rest pain - mostly in feet
necrosis and/or gangrene of the limb
history taking:- diagnosis of CLI - what things are you looking for? (8)
claudication - exercise tolerance, effect of incline, change over time, relieved by rest? Where in the leg, type of pain?
rest pain - type, relieving factors
tissue loss - duration, history of trauma, peripheral sensation
risk factors PMH DH Occupational history - daily habits Surgical history
What are the 3 visual signs of chronic ischaemia?
Ulceration
pallor - pale appearance
hair loss
What are the 2 special examination tests for CLI
Ankle Brachial pressure index - BP should be equal in both places if normal circulation
Buerger’s test - raise leg or hang over the bed
Imaging options for CLI (3)
duplex - ultrasound using both doppler and B mode
CTA/MRA
Digital subtraction angiography
pros/cons of Duplex
pros:-
dynamic
no radiation/contrast
cons:-
Not good in the abdomen
Operator dependent, time consuming
what is duplex scan
A duplex ultrasound combines: Traditional ultrasound: This uses sound waves that bounce off blood vessels to create pictures. Doppler ultrasound: This records sound waves reflecting off moving objects, such as blood, to measure their speed and other aspects of how they flow
pros/cons of CTA/MRA
Pros:-
Detailed – allows treatment planning
First line according to NICE
Cons:-
Contrast and radiation
Can overestimate calcification, difficulty in low flow states
what is digital subtraction angiography
fluoroscopy technique used in interventional radiology to clearly visualize blood vessels in a bony or dense soft tissue environment.
therapy to prevent CLI
antiplatelets
statins
what is suggested to control risk factors of CLI
BP control
smoking cessation
diabetic control
exercise
what does a surgical bypass require? (3)
inflow
a conduit:-
autologous (from same person) ie a vein from their legs or arm
or synthetic
outflow
complications associated with surgical bypass
general - bleeding, wound infection, pain, scar, DVT, PE, MI, Stroke, LRTI, death
technical- damage to nearby vein, artery, nerve, distal emboli, graft failure
pathophysiology/ functional changes associated with acute limb ischaemia (5)
Arterial embolus: MI, AF, proximal atherosclerosis (NOT DVT/PE)
Thrombosis: Usually thrombosis of a previously diseased artery.
Trauma
Aortic dissection - Extension of aortic dissection into the iliac and femoral arteries can cause impaired or absent blood flow to the lower limbs
Acute aneurysm thrombosis i.e. popliteal
define acute limb ischaemia
a sudden lack of blood flow to a limb. Acute limb ischaemia is caused by embolism or thrombosis
6 Ps - clinical signs of peripheral vascular disease/ disease of the limbs
Pain Pallor Pulse Deficit Paraesthesia - tingling sensation Paresis/Paralysis Poikilothermia (cold)
what are you wanting to find out in a history for CLI? (5)
cardiac history
onset/duration of symptoms
history of chronic limb ischaemia
risk factors for CLI
functional status - ability to perform normal daily activities required to meet basic needs
what is compartment syndrome
muscle ischaemia
- pressure within the muscles builds to dangerous levels. This pressure can decrease blood flow, which prevents nourishment and oxygen from reaching nerve and muscle cells.
can be acute or chronic
presentation of compartment syndrome
tense, tender calf
oedema, inflammation, venous obstruction
risk of renal failure due to myoglobin being present in urine due to tissue destruction
management of LI:- if the limb is salvageable then what are your options?
suspicion of embolus only - embolectomy
suspicion of thrombosis in situ (in original place not moved) - mechanical thromboectomy/thrombolysis or open embolectomy +/- bypass
management of CLI:- if the limb is not salvageable then what are your options?
palliate - make symptoms/disease less severe without removing limb
or ask patient if they’re willing to have limb amputated. If yes - amputate, if no - palliate
irreversible muscle ischaemia can occur in how many hours for acute limb ischaemia?
6-8 hours
pathophysiology of diabetic foot disease
microvascular peripheral artery disease
peripheral neuropathy
foot deformity
minor trauma
mechanical imbalance
susceptibility to infection
management of diabetic foot ulcers (6)
prevention - better than cure
diligent wound care
infection - consider systemic antibiotics
investigate for osteomyelitis, gas gangrene, necrotising fasciitis
revascularisation - very distal disease - distal bypass or distal crural angioplasty/stent
amputation - high amputation rate
other treatment that can be used alongside primary treatment for diabetic foot ulcers
dressings
debridement- larval therapy - maggots onto unhealing wound
negative pressure wound closure
skin grafts
venous leg ulcer
A leg ulcer is a long-lasting (chronic) sore that takes more than 4 to 6 weeks to heal. They usually develop on the inside of the leg, just above the ankle
