The vascular system and stroke - Acute and chronic limb ischaemia Flashcards
What is peripheral arterial disease (PAD) ?
PAD is a term used to describe a narrowing or occlusion of the peripheral arteries, affecting the blood supply to the lower limbs
a) What is PAD most commonly caused by?
b) Which gender is it more common in?
c) How is the prevalence affected as you age?
d) What two diseases is it associated with?
a) Atherosclerosis
b) Males
c) Prevalence rises with age
d) Coronary artery disease and cerebrovascular disease
List 6 important modifiable risk factors of PAD
- Smoking (most important)
- Diabetes
- Hypertension
- Obesity
- Hyperlipidaemia
- Hypercholesterolemia
- Hyperhomocysteinemia
- C-reactive protein
What classification is used to classify the clinical presentation of PAD?
Fontaine classification
Describe the different stages and symptoms of the Fontaine classification
Stage I - asymptomatic
Stage II - Claudication
Stage Iia - Pain-free, claudication walking > 200m
Stage Iib - Pain-free, claudication walking < 200m
State III - Rest/nocturnal pain
State IV - Necrosis/gangrene
a) What is the most common sign of PAD?
b) Why is this sign important?
a) Asymptomatic PAD
b) Detection of symptomatic PAD identifies patients at increased risk of atherosclerosis in other vascular territories
What factors will encourage you to investigate and asymptomatic patient with PAD
- Abnormal or absent pedal pulses
- Age =/> 70 years
- Age 50-69 years and history of smoking or diabetes
Describe the investigation process for asymptomatic PAD
What is the most common symptom of PAD?
Intermittent claudication
Explain and describe what intermittent claudication is
- Exercise-induced muscle pain due to a lack of oxygen when you exercise
- Most commonly affects the calf, thighs and buttocks
- Relieved by rest
What is the distribution of disease of the following intermittent claudication site:
a) Buttock and hip
b) Thigh
c) Upper 2/3 of calf
d) Lower 1/3 of calf
e) Feet
a) Aortoiliac disease (Leiriche syndrome triad - laudication, erectile dysfunction, and decreased distal pulses)
b) Aortoiliac or common femoral artery
c) Superficial femoral artery
d) Popliteal artery
e) Tibial or peroneal artery
Where is the intermittent claudication found in the follow distribution of disease:
a) Aortoiliac
b) Aortoiliac or common femoral artery
c) Superficial femoral artery
d) Popliteal artery
e) Tibial or peroneal artery
a) Buttock and hip
b) Thigh
c) Upper 2/3 of calf
d) Lower 1/3 of calf
e) Feet
What are the atypical symptoms of PAD?
- Pain similar to classic claudication, but does not cause the patient to stop walking
- Pain similar to classic claudication, but does not involve calves or does not resolve within 10 minutes of rest
- Leg pain on both excretion and rest
What is chronic limb threatening ischaemia (CLTI)/critical limb ischaemia
A decrease in limb perfusion that causes a potential threat to limb viability in patients who present > 2 weeks after onset of symptoms
What are the 4 symptoms of chronic limb threatening ischaemia
- Ischaemic rest pain
- Tissue loss
- Ischaemic ulcer
- Gangrene
What are the two types of gangrene?
Dry (ischaemic) gangrene
Wet (infectious) gangrene
a) What is dry (gangrene)
b) What are the common causes of dry (ischaemic) gangrene
c) Is infection usually present?
d) Describe the management of dry (ischaemic) gangrene
a) Dry gangrene is ischaemic gangrene. It is necrosis that is secondary/develops due to cholerically reduced blood flow
b) Diabetes and tobacco smoking
c) No
d) Can be left to auto-amputate or can be amputated after revascularisation
a) What is (infectious) gangrene occur?
b) Why is wet gangrene a very serious and life threatening condition if not treated quickly?
c) Describe the management of wet (infectious) gangrene
a) Liquefactive necrosis due to infection. The tissue swells and blisters and is called “wet” because of pus
b) Infection from wet gangrene can spread quickly throughout the body
c) broad-spectrum IV high dose Abx
Revascularisation, debridement +/= amputation
Describe the difference between dry (ischaemic) gangrene and wet (infectious) gangrene
Dry (ischaemic) gangrene - patients do not show sign of infection
Wet (infectious) gangrene - Patients are pyrexial/septic
What investigation would you do to investigate PAD?
- Duplex ultrasound
- CT angiography
- MR angiography
- Contrast angiography
a) Why is contrast angiography avoided?
b) When would you do a contrast angiography in a patient being investigated for pad?
a) it is an invasive procedure and so has more complications
b) If the running investigations do not give sufficient information
Describe the management of PAD in asymptomatic patients or patients with mild claudication
Conservative - lifestyle modifications
- Smoking cessation
- Supervised exercise classes - 2 hrs weekly for 3 months
- Diet control
Pharmacological therapy - manage CVD risk
- Risk factor modification (control DM, BP with antihypertensives, cholesterol)
- Anti-platelet therapy (clopidogrel 75mg)
- Anti-cholesterol therapy with statins (80mg atorvastatin nightly)
Describe the management of PAD causing short distance claudication
Conservative - lifestyle modification
- Supervised exercise classes - 2 hrs weekly for 3 months
Pharmacological therapy - manage CVD risk
- BP/DM/Cholesterol control
- Antiplatelets (Clopidogrel 75mg, aspirin if contraindicate) and statins (atorvastatin 80mg nightly)
- Naftidrofyrl oxalate (vasodilator which alleviates pain in PAD)) / Cilostazol ( improves symptoms of claudication)
Endovascular
- Angioplasty +/- stent placement
Surgical revascularisation
- Endarterectomy
- Peripheral bypass graft (autologous graft/prosthetic)
Describe the management of chronic limb threatening ischaemia
- Lifestyle modification and wound care
- Pharmacological therapy
- Revascularization via angioplasty/endarterectomy/bypass (to relieve rest pain or for management of tissue loss/gangrene to avoid amputation)
- Amputation
a) What is angioplasty?
b) How does excessive calcification effect angioplasty
c) What are the complications?
a) Angioplasty is pressure controlled balloon inflation to fracture arterial plaque and remodel the artery
b) Excessive calcification is resistant to angioplasty
c)
- Arterial puncture site haemorrhage
- Arterial rupture
- Dissection
- Distal embolisation
- Contrast induced nephropathy
Stents is an endovascular surgical option to treat PAD causing short distance claudication.
a) What are stents
b) What are the two types of stents?
a) Stents are supportive frameworks that apply radial force to diseased arteries and promote vessel remodelling
b) Balloon expandable and self-expanding stents
What is the indication to use endarterectomy to treat PAD?
When PAD causes short distance claudication and the lesion is in a readily accessible site such as the common femoral artery
What type of bypass can be used to treat PAD and include what they can be constructed from
- Infra-inguinal bypass (can be constructed from autologous or prosthetic graft)
- Aorto-iliac, femoral-femoral crossover and axillo-bifemoral bypass -(constructed using prosthetics graft)
Describe the prognosis of intermittent claudication
- Over a 5-year period most people continue to have stable claudication
- 10-10% develop worsening symptoms
- 5-10% develop critical limb ischaemia
-Amputation is eventually required in roughly 1-2% of people with intermittent claudication - This increases to 5% in people with diabetes
Of people with critical lim ischaemia, how many are estimated to need a:
a) revascularisation procedure?
b) lower limb amputation within a year of diagnosis without revascularisation
a) 50-90%
b) 1/3
What is acute limb ischaemia (ALI)?
A sudden decrease in limb perfusion that causes a potential threat to limb viability in patients who present within 2 weeks of the acute event
Describe the aetiology of ALI
Mainly caused by thrombosis or embolisation
Embolus - cardiac source
- AF
- MI
- Endocarditis
- Atrial myxoma
- Prosthetic valves
Embolus - arterial source
- Aneurysm
- Atherosclerotic plaque
Thrombosis
- Vascular grafts
- Atherosclerosis
- Thrombosis of aneurysm
- Entrapment
- Hypercoaguable state
Trauma
- Blunt
- Penetrating
- Iatrogenic
Describe the clinical features of acute lime ischaemia (The 6 P’s)
- Pain
- Pallor
- Pulselessness
- Poikilothermic (Perishingly cold)
- Paraesthesia
- Paralysis
What is the name of the classification used to classify acute limb ischaemia?
Rutherford classification
Describe the different categories of acute limb ischaemia using the Rutherford classification. Include the prognosis, the sensory loss and muscle weakness and if the arterial and venous doppler sounds are audible or inaudible
What investigations can you do for acute limb ischaemia
- ECG (in particular lookout for arrhythmias like AF)
- BM (blood sugar)
- Bloods
- FBC
- U&Es
- LFTs
- Clotting screen
- Group and save
- VBG/ABG (obtain a lactate measurement)
- Consider a thrombophilia screen
Describe the imaging techniques used to diagnose acute limb ischaemia
- Duplex ultrasound
- CT angiography (diagnostic)
- Digital subtraction angiography (DSA)
Describe the initial management of acute limb ischaemia
- ABC
- Analgesia
- FBC
- U&E
- Baseline clotting profile
- IV Heparin bolus followed by continuous heparin infusion (once diagnosis of acute arterial occlusion has been made)
What are the treatment options/definitive management for acute limb ischaema?
Endovascular therapies
- Percutaneous catheter-directed thrombolytic therapy
- Percutaneous mechanical thrombectomy/thrombo-aspiration
Surgical interventions
- Surgical thromboembolectomy
- Endarterectomy
- Bypass surgery
- Amputation of the limb if unsalvageable
Describe the process of thromboembolectomy
- Passage of fogarty catheter down affected artery beyond thrombi-embolus
- Pull back fogarty through artery and through arteriotomy retrieving the thrombo-emobuls
- Repeat process until vessel cleared and good back-bleeding established
How must you treat a non-viable extremity?
Should undergo prompt amputation or be palliated
Describe the complications of acute limb ischaemia?
Compartment syndrome - reperfusion of ischaemia muscles can cause oedema and increased compartmental pressure
Reperfusion injury - products of cell death (e.g., potassium, phosphate and myoglobin) are released when blood flow to the ischaemic limb us restored. This can result in rhabdomyolysis, cardiac dysrhythmia, AKI, multi organ failure and disseminated intravascular coagulation
Describe the prognosis of acute limb ischaemia
Mortality rate is 15-20%
a) What is acute on chronic ischaemia?
b) What are the causes?
c) What are the signs?
d) What imaging is used for diagnosis?
e) Describe the management
a) patients who present with thrombosis/embolism on a background of PAD
b)
- Rupture of atherosclerotic plaque
c)
- Previous history of asymptomatic/symptomatic PAD
- Previous onset of new symptoms of ALI
d) CT angiography or contrast angiography
e)
- Surgical bypass procedure if patient has run off (good back vessels below blockage)
- Thrombolysis or amputation if no run off
Define the following terms:
a) Amputation
b) Disarticulation
c) Prosthesis
d) Orthosis
a) The removal of a limb, part or total from the body
b) The removal of a limb from a joint
c) Artificial substitute or replacement of part of the body
d) Device externally applied to body segment to improve, support, correct or compensate weakness
What do you cake the following amputations that occur:
a) Below knee
b) Above knee
c) Above elbow
a) Transtibial
b) Transfemoral
c) Transhumeral
What is a stump?
Residual limb
Describe the incidence of amputations
- Common in 50-70 year old
- More common in males (M:F –> 3:1)
- lower limb mutation (85%) > upper limb mutation (15%)
What is the aetiology of lower and upper limb amputations
Lower limb
- Vascular 80% (approx 50% DM)
- Traumatic 10%
- Malignancy 5%
Upper limb
- Trauma 65%
- Malignancy 13%
- Congenital 3%
Name the different amputation levels of the upper limb
Name the different amputation levels of the lower limb
a) Describe the relationship between the level of amputation and the energy expenditure
b) What does the energy required depend on?
a) The higher the level, the higher the energy expenditure
b)
- Level of amputation
- level of stump
- length of stump
- Patient’s health comorbidities
- Reason for amputation
What framework is rehabilitation medicine based on?
International classification of functioning, disability, and health (ICF) framework
What are the components of the international classification of functioning, disability, and health (ICF) framework
Describe what is involved in post-op care of an amputation
- Wound management
- Oedema reduction
- Contracture prevention
- Preservation of strength and mobility in uninvolved limbs
- Psychological support
- Post-op pain management
- Stump preparation
- Wheelchair skills
Describe what is involved in the artificial limb fitting and training
- Goal establishment
- Stump casting and measurement and limb prescription from week 3 post-op
- Gait re-training
- Education on skin care, and artificial limb maintenance
Describe the role of rehabilitation for amputations on the ward
- Long-term follow up
- Early Walking Aids (EWAs)
- Gait re-training sequence
Describe what is involved in the long-term follow up of amputations
- Check if new limb is required
- Check for changes in stump size and condition
- Check for changes in residual limb
- Pain management and medical complication
Describe the gait retraining sequence
- Full weight-bearing and transfer
- Walking with parallel bars
- Walking with 2 sticks between parallel bars
- Walking with 1 stick between parallel bars
- Walking with 1 stick outside of bards
- Optimal gait with or without stick
When should amputation rehabilitation start?
Ideally start before the amputation
What should be assessed in the pre-operative assessment of an amputation
- The affected limb
- The unaffected limb
- The patient as a whole
- Assessment of the physical, social and psychological status of the patient
Describe the basic aims of the rehabilitation medicine for amputations
- To prevent post operative complications
- To prevent deformities
- To maintain general mobility
- To control stump oedema
- To maintain strength of whole body and increase strength of muscle controlling the stump
- To improve balance and transfer
- To re-educate walking
- To restore functional independence
- To treat phantom pain
What are the complications of amputations?
- Oedema
- Infection
- Ischaemia
- Non-healing
- Joint contracture
- Neuroma formation
- Neuropathic
- Phantom limb pain
- Wound breakdown
- Bony overgrowth
- Skin complications such as folliculitis, boils, abscesses, allergic dermatitis, verrucous hyperplasia, hyperhidrosis, tines corpsos
What is the triad of ischaemic pain at rest?
Burning pain that is worst at night, when the leg is elevated, and is relieved by hanging the leg off the bed
Describe the location of the scars and the selected vascular surgeries
a) Femero-popliteal bypass scars
b) Femoral-femoral bypass scars
c) Axillo-femoral bypass scars
d) Ileo-femoral bypass scars
a) would result in a vertical groin scar and a distal lower limb scar
b) Would result in two vertical groin scars.
c) Would result in a scar over the left pectoral region and left groin.
d) Will result in an oblique scar to access the iliac arteries, and vertical groin scar to access the femorals.
Can a normal ABPI in a diabetic patient exclude PAD?
A normal ABPI CANNOT exclude peripheral vascular disease in a diabetic patient and they will almost certainly need further investigation.
What is first line imaging modality of PAD and why?
- Duplex ultrasound
- Faster, cheaper, less invasive and easier to perform than CT, MR and digital subtraction angiography
What are the imaging used to investigated PAD and describe their indications for us
Duplex arterial ultrasound - for those who might be suitable for revascularisation. Can determine the site, severity and length of stenosis.
MR arteriogram - used for those who are candidates for revascularisation
CT arteriogram - used in those unsuitable for MR
Digital subtraction angiography - usually performed at the time of intervention or for monitoring disease
a) What is Fournier’s gangrene?
b) Describe the management and what warrants this management
a) Necrotizing fasciitis of the perineum (wet gangrene)
b) Surgical debridement/amputation - can cause rapid and uncontrollable necrosis of tissue and lead to death by sepsis if not treated promptly
Wet gangrene is infectious gangrene. What does it include?
- Necrotising fasciitis (infection of the subcutaneous fascia and fat)
- Gas gangrene (caused by Clostridium)
- Gangrenous cellulitis (in the immunocompromised).
Describe the difference between onset of an ischaemia acute stroke due to an embolic cause and due to a thrombosis
Acute limb ischaemia due to an embolic obstruction tends to produce symptoms over minutes. Thrombosis-induced acute limb ischaemia develops over hours to days
a) What is phantom pain?
b) What is the mechanism of phantom pain?
a) Painful sensations that feel as though they are coming from the portion of the limb was amputated
b) Unknown
Describe the 3 proposed theoretical mechanisms to explain phantom limb pain
- Peripheral mechanisms - stump and neuroma hypersensitivity
- Central neural mechanisms - spinal cord sensitization and changes, coritcal re-organisation and cortical sensory motor dysfunction
- Psychological factors - grieving, depression
Describe the management of phantom pain
Prevention
- preoperative pain control
Treatment
- Treat modalities
Pharmacological
- Analgesia, anticonvulsants (gabapentin, prcegablin, carbamazepine), low dose amitriptyline (10mg then increase gradually up to 50mg)
Miscellaenous
- Baclofen
- Botulinum
- Beta blocker
Physcial
- Massage
- Heat
- Acupunture
- Electromagnetic
- TENS
- Mirror therapy
- Virtual reality
a) Local stump complications include skin breakdown/ulcers and pressure areas. What can this be due to?
b) What is the management of this?
a)
-Poor donning technique
- Poor socket fit
- Associated neuropathy
- Change in stump volume
- Change in gait pattern
- Infection with or without ischaemia
b)
- Establish the cause
- Minimise prosthetic use
- Dynamic socket fitting/repeat casting
- Antibiotics
- Regular dressing and review
What are the components of a transtibial (TT) artificial limb
- Socket
- Suspension mechanism
- Shin tube
- Shock/torque absorber
- Foot
What are the components of a transferral (TF) artificial limb?
- Socket
- Suspension mechanism
- Adaptor
- Knee
- Shin tube
- Shock/torque absorber
- Foot
K-levels are a rating system used by Medicare to indicate a person’s rehabilitation potential. Describe the
K0: non ambulatory (bed bound)
K1: Limited to transfer or limited to household ambulator
K2: Unlimited household but limited community ambulatory
K3: Unlimited community ambulatory
K4: High energy activities (sports, work)
a) What is a microprocessor knee?
b) What are the advantages?
c) What are the disadvantages?
a) An artificial knee joint which includes a battery-powered, built-in, programmable computer that continuously controls user’s gait
b)
- Improved safety
- Computer adjusting knee for variable gait cycle
- Energy saving
c)
- Highest cost
- Heavy
- Increased maintenance
- Inconvenience of daily charging
Describe the complications of a carotid endarterectomy
- Hypoglossal nerve lesion - rare injury and due to prxomitiy to carotid artery (causes tongue to deviate towards side of the lesion)
Ischaemic gangrene is classified according to pathophysiology. Describe the classification
It occurs due to
- Atherosclerosis (in association with peripheral arterial disease)
- Thrombosis (in association with vasculitis and hypercoagulable states)
- Vasospasm (in association with cocaine use and Raynaud’s).
