Flashcards in Chronic arterial insufficiency Deck (43):
What proportion of patients with PVD are symptomatic?
Name the 2 conditions associated with chronic lower limb ischaemia
Critical limb ischaemia
What is the underlying cause of intermittent claudication and critical limb ischaemia?
Name 5 risk factors for peripheral vascular disease
Diabetes mellitus (4x)
CAD or CVD
Define intermittent claudication
Muscle pain of the lower limb on walking exercise, that is relieved by a short period of rest. Onset of symptoms >2 weeks.
Where does intermittent claudication most commonly manifest?
Outline the prognosis of intermittent claudication
1/3 remain stable
4% require intervention
2% result in amputation
Name 3 differentials for intermittent claudication
OA (esp hip)
Popliteal artery entrapment (rare)
Name the vessels affected in intermittent claudication
Superficial femoral artery (80%)
Aorto-iliac arteries (15%)
Calf arteries (5%)
What are the 3 presentations of intermittent claudication?
Calf claudication (80%)
Calf, thigh, and buttock claudication (18%)
Leriche's syndrome (2%)
What is Leriche's syndrome?
Aorto-Iliac occlusion disease.
A chronic lower limb ischaemia characterised by:
-Bilateral buttock claudication
-Absent femoral pulses
Describe the illness course of intermittent claudication
80% show no progression over 5 years.
After 5yr, 11% who smoke undergo amputation.
What is the impact of smoking on intermittent claudication outcome?
After 5 years, 11% of smokers with claudication will undergo amputation. Compared to 0% who stop smoking.
Smoking also increases mortality.
What is the impact of diabetes on intermittent claudication outcome?
Amputation rate over 5 years in 4x that of non-diabetics.
Increased risk of bypass failure.
What investigations should be ordered in intermittent claudication?
Serum lipids and cholesterol
Ankle/brachial pressure index
Duplex ultrasound: to all people for whom revascularisation is being considered.
What is the role of full blood count in intermittent claudication management?
Assess the presence of anaemia, as it can aggravate vascular disease.
What results of Ankle/brachial pressure index indicate normality and arterial disease?
Arterial disease <0.9
Outline the treatment of intermittent claudication
Risk factor modification
Angioplasty and stent
Surgical bypass or graft
What are the indications for surgical intervention of intermittent claudication?
Short distance claudication
Severe lifestyle limitation
Failure/unsuitable for endovascular treatment in aorto-iliac arteries
What pharmacological treatments should patients with intermittent claudication be given?
20mg Atorvastatin (80mg in secondary prevention)
Daily Clopidogrel (300mg loading, 75mg), or
If T2DM: metformin
What non-pharmacological intervention is beneficial for intermittent claudication?
Supervised exercise programme: 2hr/wk for 3 months. Encourage to exercise to point of maximal pain.
Otherwise, 30min 3-5x per week until onset of symptoms.
Improves walking technique and capillary perfusion. Optimises collateral blood distribution.
Define critical limb ischaemia
Rest pain for >2wk that is not relieved by simple analgesia, OR
Doppler ankle pressure <50mmHg
Tissue necrosis (ulceration or gangrene)
How does the diagnostic criteria for critical limb ischaemia differ in diabetics?
Toe pressure <30mmHg if diabetic
Describe the clinical features of critical limb ischaemia
Rest pain is worse at night and during elevation of limb.
This is relieved by hanging the limb.
How does critical limb ischaemia appear on examination?
Sunset foot - due to compensatory vasodilation
Describe Buerger's test and its indication
Used to test the adequacy of arterial supply to the legs.
1. Whilst supine, elevate the patient's legs 45 degrees for 1-2min.
2. Patient sit at end of bed with legs dangling.
Ischaemia will show as pallor when elevated, and dark red when dangled due to reactive hyperaemia.
The poorer the supply, the less elevation required for pallor.
What investigations should be ordered in critical limb ischaemia?
Identify all arterial stenoses using:
Colour duplex Doppler USS
Magnetic resonance angiogram (MRA)
CT angiogram (CTA)
Describe the management of critical limb ischaemia
Revascularise where possible, starting proximally.
Urgent referral to vascular team
Optimise medical management (nursing care, analgesia)
Angioplasty + stent (proximal)
Bypass surgery or graft (distal)
How does the aetiology differ between intermittent claudication and critical limb ischaemia?
Intermittent claudication usually results from single-level atherosclerosis.
Critical limb ischaemia usually results from two-level atherosclerosis.
Outline the Fontaine classification of lower limb ischaemia
Clinical classification of Peripheral artery disease:
II. Intermittent claudication
III. Rest pain
Critical limb ischaemia = Grades III and IV
What are the features of diabetic foot?
Infection (cellulitis, abscess, osteomyelitis)
Failure to heal trivial injuries
Name 4 risk factors for ulceration in diabetic foot
Neuropathy (stocking distribution and Charcot foot)
Peripheral arterial disease - frequently highly calcified
Altered foot shape
Callus - high foot pressures
What are the causes of ulceration in diabetic foot?
Ischaemia of large or small vessels (10%)
Mixed neuropathic-ischaemic origin (45%)
Describe the presentation of diabetic foot with pure neuropathic ulceration
Warm foot with palpable pulses
Ulceration at pressure points
Evidence of sensory loss ➔ unrecognised repeated trauma
Normal or high duplex USS flow
Describe the presentation of diabetic foot with ischaemic or mixed ulceration
Foot may be cool
Ulcers commonly on toes, heel, metatarsal
Secondary infection with minimal pus and mild cellulitis
ABPIs may be misleadingly high due to calcification (diabetes)
Low duplex USS flow
What investigations can be used to differentiate the causes of diabetic foot ulceration?
Ankle/brachial pressure index
Angiography - suspected critical limb ischaemia
Outline prophylactic management of ulceration in diabetic foot
Specialist diabetes foot clinic with MDT
Regular foot inspection
Nail care with chiropody
Debridement of calluses
Keep foot cool
Avoid walking barefoot
Outline management of infection in established ischaemic ulceration
Treat local or systemic infection following trust ABX guidelines
Debride/amputate any necrotic tissue
X-ray for osteomyelitis
What surgical options are available for diabetic foot?
Femoro-distal bypass graft
What surgical considerations must be made for diabetic patients?
Renal disease: close monitoring of hydration, BP and eGFR
Metformin stopped 48hr prior to angiography due to risk of lactic acidosis
T1DM require sliding scale when NBM
Elevate legs to avoid pressure sores
Prompt attention to any skin breaks
What infections may occur in poorly managed ulcerations of diabetic foot?
Deep tissue infections - plantar abscess
What is the management of osteomyelitis of the toe or metatarsal?
Ray excision - surgical removal of toe and metatarsal