Acute Limb Ischaemia Flashcards
What is acute limb ischaemia?
The sudden decease in limb perfusion that threatens the viability of the limb. Can be caused by complete or partial occlusion and occurs within hours.
What can cause acute limb ischaemia?
- Embolus (most common)
- Thrombus (atheromatous plaque rupture)
- Trauma (least common)
What causes emboli in acute limb ischaemia?
- AF
- Post-MI
- Mural-thrombus
- AAA
- Prosthetic heart valves
Name an example of trauma
Compartment Syndrome
What are the clinical features of acute limb ischaemia?
6 Ps
- Pain
- Pallor
- Pulselessness
- Paraesthesia
- Perishingly cold
- Paralysis
Which of the 6 Ps are most common?
- Pain
- Pallor
- Pulselessness
If the contralateral limb is warm and pulsatile, what is the most likely diagnosis?
Embolism
What are the categories of acute limb ischaemia?
Rutherford's 1- Viable 2a- Marginally Threatened 2b- Immediately Threatened 3- Irreversible
Outline a stage 1 case in terms of:
- Prognosis
- Sensory Loss
- Motor Deficit
- Arterial Doppler
- Venous Doppler
Viable
- Prognosis - No immediate threat
- Sensory Loss - None
- Motor Deficit - None
- Arterial Doppler - Audible
- Venous Doppler - Audible
Outline a stage 2a case in terms of:
- Prognosis
- Sensory Loss
- Motor Deficit
- Arterial Doppler
- Venous Doppler
Marginally Threatened
- Prognosis - Salvageable if treated promptly
- Sensory Loss - Toes, if any
- Motor Deficit - None
- Arterial Doppler - Inaudible
- Venous Doppler - Audible
Outline a stage 2b case in terms of:
- Prognosis
- Sensory Loss
- Motor Deficit
- Arterial Doppler
- Venous Doppler
Immediately Threatened
- Prognosis - Salvageable if immediately revascularised
- Sensory Loss - More than toes/Rest pain
- Motor Deficit - Mild/Moderate
- Arterial Doppler - Inaudible
- Venous Doppler - Audible
Outline a stage 3 case in terms of:
- Prognosis
- Sensory Loss
- Motor Deficit
- Arterial Doppler
- Venous Doppler
Irreversible
- Prognosis - Major tissue loss/Inevitable
- Sensory Loss - Profound
- Motor Deficit - Paralysis
- Arterial Doppler - Inaudible
- Venous Doppler - Inaudible
When is irreversible damage expected to begin?
6 hours after symptom onset
How should suspected cases be imaged?
- Doppler USS
- CT angiogram immediately after
What bloods should be done?
- Full profile
- Group and save
- INR (hypercoaguability)
- ABG (Lactate to assess level of ischaemia)
What initial management is important?
- Investigations
- Surgical referral
- Oxygen
- Therapeutic dose heparin
- IV Access
- Analgesia
When can conservative management be used/trialled instead of surgery?
Rutherford’s 1 or 2a
What is the conservative management?
- Treatment dose heparin (prolonged course)
- Regular follow up with APTTs
What surgeries are used in embolic cases?
- Embolectomy via Fogarty catheter
- Local intra-arterial thrombolysis
- Bypass surgery (if there is insufficient flow back)
What surgeries are used in thrombotic cases?
- Local intra-arterial thrombolysis
- Angioplasty/stenting
- Bypass surgery
How are irreversible cases surgically treated?
Amputation
How are cases managed long-term post surgery?
- Reduce cardiovascular risk
- Anti-platelets/anti-coagulation
- OT/Physio, especially with amputation
What is the mortality of acute limb ischaemia?
20% at 5 years
What can reperfusion result in?
Reperfusion injuries
- Compartment syndrome
- Release of substances from the damaged muscle cells
What can be released from damaged muscle cells?
- K+ ions causing hyperkalaemia
- H+ ions causing acidosis
- Myoglobin, resulting in AKI
