Peripheral vascular disease Flashcards
What causes intermittant claudication? what are the clinical features?
This occurs when insufficient blood reaches exercising muscle.
The patient is pain-free at rest, but after variable periods of exercise develops ischaemic pain in the affected limb, which is relieved by further rest.
How is peripheral vascular disease staged?
Fontaine stage: I: normal IIa: intermittant claud. >200m IIb: intermittant claud. <200m III: rest pain IV: tissue loss
what are the main risk factors for peripheral vascular disease? (6)
Male Age Diabetes Smoking HTN Hypercholesterolaemia
What are the pulses that you feel for in the leg?
- Femoral
- Popliteal
- Posterior tibial
- Dorsalis pedis
What are the 2 non-invasive investigations for lower limb ischaemia?
Measurement of ABPI:
Ankle pressure/Brachial pressure (this is usually the same but as get worse, ankle pressure becomes alot lower than brachial)
-Duplex USS
What is a normal/claudication/severe ABPI?
Normal: 0.8-1.2
Claudication: 0.4-0.85
Severe: 0-0.45
What are the 3 invasive investigations for lower limb ischaemia?
Magnetic resonance angiography
CT angiography
Catheter angiography
What are the important lifestyle factors to discuss with a patient who has lower limb ischaemia?
stop smoking (smoking is a risk factor for amputation)
importance of walking to develop collateral circulation and success of supervised exercise programmes
What pharmacological management is involved in the treatment of lower limb ischaemia?
lipid lowering
antiplatelets
hypertension Rx
diabetes Rx (diabetes is a risk factor for amputation)
What is the surgical management of lower limb ischaemia?
angioplasty
stent
bypass
What are the 5 clinical features of critical limb ischaemia? What are these helped by?
Rest pain (lying/sleeping) = toe / foot ischaemia (nerve ending pain)
Ulcers/gangrene (trauma/footwear) = severe ischaemia and damage
Toes and forefoot
Requires strong analgesia
Worse at night
Helped by:
- sitting and putting the leg in a dependent position
- getting up and walking about
What is the main management of intermittant claudication and critical limb ischaemia?
RISK REDUCTION
What is acute limb ischaemia?
sudden loss blood supply to a limb:
-occlusion native artery or bypass graft
what are 5 causes of sudden occlusion?
- Embolism
- Atheroembolism
- Arterial dissection
- Trauma
- Extrinsic compression
What are the 6 P’s of acute limb ischaemia?
Pain Pallor Pulseless Perishingly cold Paraesthesia Paralysis
in acute limb ischaemia:
- describe pain
- what does a tight ‘woody’ compartment indicate?
Severe, sudden onset, resistant to analgesia
Calf/muscle tenderness with tight (‘woody’) compartment indicates muscle necrosis
Often irreversible ischaemia
Describe the colour changes in the skin in acute limb ischaemia?
Limb initially white with empty veins
Later, capillaries fill with stagnated de-oxygenated blood giving a mottled appearance:
-Blanching mottling = salvageable if prompt revascularisation
Arteries distal to occlusion fill with propagated thrombus with rupture of capillaries
=Non blanching mottling = irreversible ischaemia
Describe the clinical features seen:
0-4 hrs
4-12 hrs
>12 hrs
0-4hrs: -white foot -painful -sensorimotor deficit SALVAGEABLE
4-12hrs:
-mottled
-blanches on pressure
PARTLY REVERSABLE
>12hrs: -fixed mottling -non-blanching -compartments red and tender -paralysis NON-SALVAGEABLE
What is the management for acute limb ischaemia?
- bloods?
- Investigations?
- initial pharmacological mgt?
ABC – resuscitate and investigate
FBC, U/Es, CK, Coag +/- Troponin
ECG – MI, dysrhythmia
CXR – underlying malignancy
Anticoagulate:
- Stops propagation of thrombus
- May improve perfusion
- Regional vs General Anaesthesia
When would you consider arterial imaging for acute limb ischaemia?
- No prior history of claudication
- Cause for embolism known
- Full complement of contra-lateral pulses
If doubts as to history: urgent CT angio/Catheter angio
If limb is salvageable, what is the surgical management for acute limb ischaemia?
-Embolectomy
+/-
-fasciotomies
-thrombolysis
If limb is not salvageable what is the management for acute limb ischaemia?
Palliation or amputation
why is important to distinguish between acute vs acute on chronic acute limb ischaemia?
Different urgency and management
Importance of accurate history and exam
What do diabetic foot problems encompass? what does this lead to?
Diabetic neuropathy
Peripheral vascular disease
Infection
Leads to tissue ulceration/necrosis/gangrene
May result in amputation
What are the 3 different sources of diabetic foot sepsis?
simple puncture wound
infection from the nail plate or inter-digital space
from a neuro-ischaemic ulcer (occurs on areas of increased pressure, ie under the metatarsal heads).
Why does the anatomy of the foot mean diabetic foot sepsis is a vascular surgical emergency?
Within the foot the intrinsic muscles of the digits are confined within rigid compartments bounded by plantar fascia, metatarsal bones and interosseous fascia.
Infection tracks in the soft tissues into this rigid compartment
if the build up of pus can’t escape = pressure builds up in the compartments = ischaemia/further tissue damage
=can rapidly progress to sepsis and ultimately limb loss
(more of a pressure problem rather than an ischaemic problem)
What are the clinical systemic signs 5 seen in diabetic foot sepsis?
Pyrexia Tachycardic Tachypnoeic Confused Kussmauls breathing
What are the local signs seen in diabetic foot sepsis? 7
Swollen affected digit (‘sausage’ like)
Swollen forefoot (‘boggy’ feeling to swelling)
Tenderness
Ulcer with pus extruding
Erythema, may track up the limb
Patches of rapidly developing necrosis
Crepitus in the soft tissues of the foot (Gas from gas forming organisms)
(may or may not feel pedal pulses)
what organisms can cause diabetic foot infection?
Gram +ve cocci (S. aureus + Streptococcus sp.)
Gram –ve bacilli (E. coli, Klebsiella sp, Enterobacter, Proteus sp and Pseuodomonas sp.)
Anaerobes (Bacteroides)
What is the management of diabetic foot sepsis?
Abiotics
Rapid surgical debridement of infected tissue
If performed at early stages the foot and limb may be salvaged
Remove all infected tissue
Wound open to encourage drainage
