5: Peripheral vascular disease Flashcards
What is chronic lower limb ischaemia?
Lack of blood reaching the tissues of the lower limb (inadequate perfusion)
What causes ischaemia?
Arterial obstruction due to atheroma
What are four modifiable risk factors which contribute towards endothelial cell damage?
Cigarette smoke
Hypertension
Increased conc. glucose (diabetes)
Increased conc. cholesterol
Plaque formation is due to activated ___, __ cholesterol and the ___ response.
platelets , LDL , inflammatory
Which kind of cholesterol is taken up by macrophages during plaque formation?
Oxidised LDL
What kind of peripheral vascular disease is obvious to spot in a patient?
Intermittent claudication
What are two kinds of vascular disease which are more difficult to spot in patients?
Coronary artery disease
Cerebrovascular disease
What is claudication?
Muscle ischaemia ON EXERCISE
Why may claudication be described as intermittent?
Only occurs on exertion when oxygen demand of muscle increases
Collateral arteries can deliver (more / less) blood than the obstructed artery itself.
less
Obstruction can be detected by taking a patient’s __ __ pressure index.
Ankle brachial pressure index
How is ABPI calculated?
Ankle pressure (mm Hg) / brachial pressure (mm Hg)
Are ABPI measurements systolic or diastolic?
Systolic
What else is considered apart from the ABPI when trying to figure out the occlusion of an artery?
Tone & pitch of the sound on auscultation
What tool can be used to look at the narrowing of an individual blood vessel?
Ultrasound
What lifestyle change slows the progression of lower limb ischaemia?
Stopping smoking
How often should patients with intermittent claudication exercise?
30 mins 3x per week (into pain)
Apart from exercise, the second most effective way of treating intermittent claudication is prescribing ___ drugs.
anti-cholesterol
Which surgical methods can be used to treat blocked arteries?
Angioplasty +/- stent
Inflow / outflow bypasses (look these up)
Where would pain be felt in a patient with critical limb ischaemia?
Toe/foot
When is critical limb ischaemia pain felt?
At rest:
- lying down
- sleeping
What may occur in the feet of people with critical limb ischaemia?
Ulcers, gangrene
Why do people with critical limb ischaemia develop severe damage (ulcers, gangrene) when they damage their feet (trauma, poor fitting footwear)?
Lack of blood supply –> lack of proper healing
What alleviates the pain at rest associated with critical limb ischaemia?
Getting up and walking about, moving the leg
What should you look out for on examination of the foot of a patient with critical limb ischaemia?
Cold Absence of peripheral pulses Colour change Hairless, thick nails, shiny Venous guttering Ulcers, gangrene
Why would a lower limb be amputated?
If critical limb ischaemia was threatening the patient’s life
What influences the level at which a patient’s limb should be amputated?
Healing abilities of the limb
Function of the limb
What is an aneurysm?
Dilation of a vessel by >50% of its normal diameter
What is a true aneurysm?
An aneurysm where the vessel wall is intact
What is a false aneurysm?
Breach in vessel walls (ballooning)
Name three further types of aneurysm.
Saccular (ballooning)
Fusiform
Mycotic (secondary to infection, involves all 3 layers of arterial wall)
Which layer of the blood vessel is affected in AAAs?
Tunic media
The occurrence of abdominal aortic aneurysm increases with __.
age
You are more likely to have a AAA if you are (male / female).
male
75% of AAAs are (symptomatic/asymptomatic).
asymptomatic
If a AAA is symptomatic in a patient, what would they experience?
- Pain - may mimic renal colic
- “Trashing” - thrombi breaking off from AAA and blocking arteries in legs
- RUPTURE
What is the presentation of an AAA rupture?
Sudden onset epigastic / central pain
Radiates through to back
Collapse
What would a ruptured AAA appear like on examination?
Pulsatile, expansive mass - may/may not be tender
Transmitted pulse
Peripheral pulses
What may contain the rupture of an AAA?
Peritoneum (contained if rupture is RETROPERITONEAL)
If rupture is INTRAperitoneal you will probs die
What may contain the rupture of an AAA?
Peritoneum (contained if rupture is RETROPERITONEAL)
If rupture is INTRAperitoneal you will probs die
Generally, the greater the size of the aneurysm, the more likely it is to __ and the more important it is to __.
rupture , intervene
What imaging tool can be used to look at the AP diameter of possible asymptomatic aneurysms?
Duplex ultrasound
Which imaging method involves giving the patient contrast and looking at the aneurysm’s morphology - shape, size, iliac involvement.
CT scan
A CT scan allows you to decide whether or not an AAA has ___.
ruptured
What name is given to the procedure which opens up a patient’s abdomen?
Laparotomy
Which polyester can be grafted onto the AA to repair a rupture?
Dacron
What procedure uses a stent graft to bypass the ruptured AA?
Endovascular aneurysm repair
What predisposes you to an AAA?
Smoking, hypertension
Important in treating limb ischaemia is distinguishing ___ from __-on-__ ischaemia.
acute , acute-on-chronic
What are some causes of sudden occlusion of an artery?
Embolism Atheroembolism Arterial dissection Trauma Compression
What are some causes of sudden occlusion of an artery?
Embolism Atheroembolism Arterial dissection Trauma Compression
What are the clinical features of acute limb ischaemia?
Pain Pallor (pale) Pulseless Cold Paraesthesia (pins and needles) Paralysis
What is a likely cause of acute limb ischaemia?
Embolism
Acute ischaemic pain is often resistant to ___.
analgesia
“Woody” feel of the muscle compartment indicates ___ ischaemia and muscle ___.
irreversible , death
If mottling of the skin (blue/purple) DOESN’T disappear with pressure, thrombus has spread distally and the ischaemia is ___.
irreversible
Ischaemia is irreversible beyond __ hours.
12
Malignancy makes you (pro/anti) thrombotic.
pro-thrombotic
Troponin levels are used to differentiate between ___ and __.
angina , MI
Diabetic foot problems encompass…
- Diabetic neuropathy
- Peripheral vascular disease
- Infection
Diabetic foot problems often end in ___.
amputation
Diabetic foot problems often end in ___.
amputation
How may infection be introduced to a diabetic person’s foot, leading to diabetic foot sepsis?
- Small puncture wound
- Nail infection
- Ulcers
Infection reaches the __ compartments of the foot.
muscle
Build up of what, associated with infection, increases pressure in foot muscle compartments and loss of capillary blood flow?
Pus
Build up of what, associated with infection, increases pressure in foot muscle compartments and loss of capillary blood flow?
Pus
Diabetic foot sepsis is a vascular surgical __.
emergency
What would a patient with diabetic foot sepsis look like at first glance?
Pyrexia Tachycardic Tachypnoeic Confused Kussmaul's breathing
What are some local findings associated with diabetic foot sepsis?
Swollen Tender Ulcer with pus extruding Erythema Patchy necrosis Crepitus (gas in the small tissues, produced by organisms)
What is the normal diameter of the aorta?
1.2 - 2.0cm
