Acute Limb Ischaemia Flashcards
What is Acute Limb Ischaemia? (ALI) (2 things)
- Vasc emergency
2. Caused by rapid decrease in limb perfusion
What percentage of ALI is lower limb?
80%
What are the causes of ALI? (3 things)
- Embolisation (most common)
- Thrombosis in situ
- Trauma (less common)
What is embolisation?
Thrombus travels distally to occlude artery
a cause of ALI
Where do ALI causing emboli commonly arise from? (2 things)
- Heart (AF / mural thrombus)
2. AAA
How does thrombosis occur? (2 steps)
- Atheroma plaque in artery ruptures
2. Thrombus forms on plaque’s cap
What is an example of trauma that causes ALI?
Compartment syndrome
What are the risk factors for ALI? (7 things)
- Smoking
- DM
- Obesity
- Arterial HTN
- High cholesterol
- Sedentary lifestyle
- FHx vasc disease
What are the clinical features of ALI? (6 things)
Sudden onset of 6 P’s:
- Pain
- Pallor
- Pulselessness
- Paresthesia (pins and needles)
- Perishingly cold (to touch)
- Paralysis
What should you ask about in the history to enquire about a potential embolisation? (5 things)
- Chronic limb ischaemia
- AF
- Recent MI (–> mural thrombosis)
- Symptomatic AAA (back / abd pain)
- Peripheral aneursym
What is the name of the category system for ALI?
Rutherford categories
What are the Rutherford categories for ALI? (3 things)
- Viable
- Threatened (early / late)
- Irreversible
For a VIABLE limb in the Rutherford category of ALI:
Pain at rest? Sensory loss? Motor loss? Arterial doppler audible? Venous doppler audible? Prognosis?
VIABLE
Pain at rest: NO Sensory loss: NO Motor loss: NO Arterial doppler audible: AUDIBLE Venous doppler audible: AUDIBLE Prognosis: NO THREAT
For a THREATENED limb in the Rutherford category of ALI:
Pain at rest? Sensory loss? Motor loss? Arterial doppler audible? Venous doppler audible? Prognosis?
THREATENED
Pain at rest: YES Sensory loss: MINIMAL Motor loss: MILD Arterial doppler audible: INAUDIBLE Venous doppler audible: AUDIBLE Prognosis: SALVAGEABLE IF REVASC IMMEDIATELY
For a IRREVERSIBLE limb in the Rutherford category of ALI:
Pain at rest? Sensory loss? Motor loss? Arterial doppler audible? Venous doppler audible? Prognosis?
IRREVERSIBLE
Pain at rest: YES Sensory loss: A LOT Motor loss: PARALYSIS Arterial doppler audible: INAUDIBLE Venous doppler audible: INAUDIBLE Prognosis: MAJOR TISSUE LOSS + PERM NERVE DAMAGE
What lab tests should be done for a patient with suspected ALI? (5 things)
- Routine bloods
- Serum lactate (to assess level of ischaemia)
- Thrombophilia screen
- G&S
- ECG
What imagine should be done for a patient with suspected ALI? (2 things)
- Doppler US
2. Confirmatory imaging: Digital subtraction angiography / CT angiography
What does a Doppler US in a patient with ALI show?
Absence of blood flow distal to occlusion site
How should a patient with ALI be managed initially? (3 things)
- High flow Oxygen
- IV access
- Therap dose Heparin / bolus done then infusion
How should a patient with a VIABLE / EARLY THREATENED Rutherford category ALI be managed?
Conservatively:
Prolonged heparin course (w regular APPT assessment)
How should a patient with a LATE THREATENED Rutherford category ALI be managed?
Surgically
What is the surgical management for a patient with LATE THREATENED Rutherford category ALI caused by EMBOLIC causes? (3 things)
- Embolectomy
- Local intra-arterial thrombolysis
- Bypass surgery (if insuff flow back)
What is the surgical management for a patient with LATE THREATENED Rutherford category ALI caused by THROMBOTIC DISEASE? (3 things)
- Local intra-arterial thrombolysis
- Angioplasty
- Bypass surgery
How should a patient with a IRREVERSIBLE Rutherford category ALI be managed?
Urgent amputation / palliative
