Acute limb ischaemia Flashcards

1
Q

What is Acute limb ischaemia?

A
  • Sudden decrease in limb perfusion
  • <14 day onset
    • Threatens viability of the ilmb
  • Associated with the 6 P’s
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2
Q

Causes of Acute limb ischaemia?

A
  • Thrombosis
  • Embolisation
  • Trauma
    • (including compartment syndrome)
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3
Q

What are the symptoms and signs of Acute limb ischaemia?

A
  • 6Ps
    • Pale, pulseless, painful
    • Paralysed, paraesthetic, perishing with cold
  • Emboli tend to originate from the heart:
    • AF, mural thrombosis
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4
Q

Describe how a potential acute limb ischaemia might be investigated?

A
  • Bloods
    • Serum lactate:
      • assesses level of ischaemia
    • Thrombophilia screen
  • ABPI
    • =<0.9
  • Doppler US
  • CT arteriogram
    • Can provide location information for operative approach
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5
Q

Differentials for Acute limb ischaemia?

A
  • Acute DVT
  • Critical chronic limb ischaemia
  • Spinal cord/ peripheral nerve compression
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6
Q

Describe the management of acute limb ischaemia?

A
  • Revascularisation within 6hr
  • Heparin bolus then infusion
  • Analgesia with paracetamol and opioid
  • Assess revascularisation vs amputation
  • Revascularisation options:
    • Bypass surgery
    • Local thrombolysis with tPA
    • Embolectomy via Fogarty catheter
    • Angioplasty for thrombosis
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7
Q

What are the possible complications after surgery to fix acute limb ischaemia?

A
  • Compartment syndrome
  • Reperfusion injury
    • Release of substances from damaged cells:
      • K+ => hyperkalaemia
      • H+ => acidosis
      • Myoglobin => AKI
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8
Q

Outcomes of Acute limb ischaemia?

A
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9
Q

Describe irreversible limb ischaemia?

A
  • Mottled, non-blanching appearance
  • Hard, woody muscles
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10
Q

Gold standard investigation for acute limb ischaemia?

A

CT angiography

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11
Q

What level does the aorta pass through the diaphragm?

A

T12

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12
Q

What level does the aorta bifurcate?

A

L4

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13
Q

Signs of a non-viable limb?

A
  • Tissue loss
  • Nerve damage
  • Sensory loss
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14
Q

Complications of Peripheral arterial disease?

A
  • Leg/foot ulcers
  • Gangrene
  • Permanent limb weakness/numbness
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15
Q

Describe the differences between acute, acute-on-chronic and chronic limb ischaemia?

A
  • Acute
    • Ischaemia <14 days
  • Acute-on-chronic
    • Worsening symptoms <14 days
  • Chronic
    • Ischaemia stable for >14 days
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16
Q

Describe the difference between an embolus and thrombosis cause of Acute limb ischaemia in terms of severity?

A
  • Embolus
    • Complete ischaemia (no collaterals)
  • Thrombosis
    • Incomplete ischaemia (collaterals)
17
Q

Describe the difference between an embolus and thrombosis cause of Acute limb ischaemia in terms of onset?

A
  • Embolus
    • Seconds or minutes
  • Thrombosis
    • Hours or days
18
Q

Describe the difference between an embolus and thrombosis cause of Acute limb ischaemia in terms of embolic source?

A
  • Embolus
    • Usually AF
  • Thrombosis
    • Absent
19
Q

Describe the difference between an embolus and thrombosis cause of Acute limb ischaemia in terms of previous claudication?

A
  • Embolus
    • Absent
  • Thrombosis
    • Present
20
Q

Describe the difference between an embolus and thrombosis cause of Acute limb ischaemia in terms of palpation of the artery?

A
  • Embolus
    • Soft, tender
  • Thrombosis
    • Hard, calcified
21
Q

Describe the difference between an embolus and thrombosis cause of Acute limb ischaemia in terms of bruits?

A
  • Embolus
    • Absent
  • Thrombosis
    • Present
22
Q

Describe the difference between an embolus and thrombosis cause of Acute limb ischaemia in terms of diagnosis?

A
  • Embolus
    • Clinical
  • Thrombosis
    • Angiography
23
Q

Describe the difference between an embolus and thrombosis cause of Acute limb ischaemia in terms of management?

A
  • Embolus
    • Embolectomy, warfarin
  • Thrombosis
    • Medical, bypass, thrombolysis
24
Q

What is the most important symptom in Acute limb ischaemia?

A
  • Paralysis
    • Indicates that the limb is threatened
25
Q

Describe Thoracic outlet syndrome?

A
  • Pressure on subclavian artery from cervical rib or abnormal soft tissue band
  • Can lead to post-stenotic dilation linned with thrombosis
    • Predisposition to occlusion or embolisation
  • Diagnosed with duplex US
26
Q

Treatment for Thoracic outlet syndrome?

A
  • Thrombolysis
  • Thrombectomy/embolectomy
  • Excision of cervical rib
27
Q

Contraindications for a heparin bolus in acute limb ischaemia?

A
  • Trauma
  • Suspected aortic dissection