Chronic arterial insufficiency Flashcards Preview

Phase II: Periop Pt1 > Chronic arterial insufficiency > Flashcards

Flashcards in Chronic arterial insufficiency Deck (43):
1

What proportion of patients with PVD are symptomatic?

25%

2

Name the 2 conditions associated with chronic lower limb ischaemia

Intermittent claudication
Critical limb ischaemia

3

What is the underlying cause of intermittent claudication and critical limb ischaemia?

Atherosclerosis

4

Name 5 risk factors for peripheral vascular disease

Smoking (9x)
Hypertension (3x)
Diabetes mellitus (4x)
Hyperlipidaemia
Age
FHx
CAD or CVD

5

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.

6

Where does intermittent claudication most commonly manifest?

Calf muscles

7

Outline the prognosis of intermittent claudication

1/3 improve
1/3 remain stable
1/3 deteriorate

4% require intervention
2% result in amputation

8

Name 3 differentials for intermittent claudication

Spinal stenosis
OA (esp hip)
Sciatica
Musculoligamentous strain
Popliteal artery entrapment (rare)

9

Name the vessels affected in intermittent claudication

Superficial femoral artery (80%)
Aorto-iliac arteries (15%)
Calf arteries (5%)

10

What are the 3 presentations of intermittent claudication?

Calf claudication (80%)
Calf, thigh, and buttock claudication (18%)
Leriche's syndrome (2%)

11

What is Leriche's syndrome?

Aorto-Iliac occlusion disease.

A chronic lower limb ischaemia characterised by:
-Bilateral buttock claudication
-Erectile dysfunction
-Absent femoral pulses

12

Describe the illness course of intermittent claudication

80% show no progression over 5 years.
After 5yr, 11% who smoke undergo amputation.

13

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.

14

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.

15

What investigations should be ordered in intermittent claudication?

FBC
BM
Serum lipids and cholesterol
Ankle/brachial pressure index
Exercise test

Duplex ultrasound: to all people for whom revascularisation is being considered.

16

What is the role of full blood count in intermittent claudication management?

Assess the presence of anaemia, as it can aggravate vascular disease.

17

What results of Ankle/brachial pressure index indicate normality and arterial disease?

Normal >1.1
Arterial disease <0.9

18

Outline the treatment of intermittent claudication

Risk factor modification
Angioplasty and stent
Surgical bypass or graft

19

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

20

What pharmacological treatments should patients with intermittent claudication be given?

20mg Atorvastatin (80mg in secondary prevention)
Daily Clopidogrel (300mg loading, 75mg), or
Aspirin (75mg)
If T2DM: metformin

21

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.

22

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)

23

How does the diagnostic criteria for critical limb ischaemia differ in diabetics?

Toe pressure <30mmHg if diabetic

24

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.

25

How does critical limb ischaemia appear on examination?

Cold
Sunset foot - due to compensatory vasodilation

26

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.

27

What investigations should be ordered in critical limb ischaemia?

Identify all arterial stenoses using:
Colour duplex Doppler USS
Angiography
Magnetic resonance angiogram (MRA)
CT angiogram (CTA)

28

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)
Amputation

29

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.

30

Outline the Fontaine classification of lower limb ischaemia

Clinical classification of Peripheral artery disease:
I. Asymptomatic
II. Intermittent claudication
III. Rest pain
IV. Ulcers/gangrene

Critical limb ischaemia = Grades III and IV

31

What are the features of diabetic foot?

Ulceration
Infection (cellulitis, abscess, osteomyelitis)
Sensory neuropathy
Failure to heal trivial injuries

32

Name 4 risk factors for ulceration in diabetic foot

Previous ulceration
Neuropathy (stocking distribution and Charcot foot)
Peripheral arterial disease - frequently highly calcified
Altered foot shape
Callus - high foot pressures
Visual impairment
Living alone
Renal impairment

33

What are the causes of ulceration in diabetic foot?

Neuropathy (45%)
Ischaemia of large or small vessels (10%)
Mixed neuropathic-ischaemic origin (45%)

34

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

35

Describe the presentation of diabetic foot with ischaemic or mixed ulceration

Foot may be cool
Absent pulses
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

36

What investigations can be used to differentiate the causes of diabetic foot ulceration?

Ankle/brachial pressure index
Duplex USS
Angiography - suspected critical limb ischaemia

37

Outline prophylactic management of ulceration in diabetic foot

Specialist diabetes foot clinic with MDT
Regular foot inspection
Wide-fitting footwear
Nail care with chiropody
Debridement of calluses
Keep foot cool
Avoid walking barefoot

38

Outline management of infection in established ischaemic ulceration

Treat local or systemic infection following trust ABX guidelines
Debride/amputate any necrotic tissue
Drain pus
X-ray for osteomyelitis

39

What surgical options are available for diabetic foot?

Angioplasty
Femoro-distal bypass graft
Amputation

40

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

41

What infections may occur in poorly managed ulcerations of diabetic foot?

Deep tissue infections - plantar abscess
Osteomyelitis

42

What is the management of osteomyelitis of the toe or metatarsal?

Ray excision - surgical removal of toe and metatarsal

43

What may cause the ABPI reading to be erroneously elevated?

Calcification of arteries - seen in diabetes