Acute limb ischaemia

Acute Limb Ischaemia

Acute limb ischaemia (ALI) is a sudden decrease in limb perfusion that threatens the viability of the limb. It is a medical emergency that requires prompt diagnosis and treatment to prevent limb loss and other serious complications.

Pathophysiology

Acute limb ischaemia occurs when there is a sudden reduction in blood flow to a limb. This can be due to an arterial embolism, arterial thrombosis, or trauma. The lack of blood flow leads to tissue hypoxia and can result in tissue necrosis if not promptly treated.

Causes

1. Arterial embolism: This occurs when a blood clot or other debris travels through the bloodstream and lodges in a limb artery, blocking blood flow. 2. Arterial thrombosis: This is the formation of a blood clot within a limb artery, often on top of an existing atherosclerotic plaque. 3. Trauma: Direct injury to a limb artery can cause acute ischaemia.

Clinical Presentation

Patients with acute limb ischaemia typically present with the "six Ps":

• Pain: Sudden and severe pain in the affected limb.
• Pallor: The limb may appear pale due to lack of blood flow.
• Pulselessness: Absence of a pulse in the affected limb.
• Paresthesia: Numbness or tingling in the limb.
• Paralysis: Weakness or inability to move the limb.
• Poikilothermia: The limb may feel cold to the touch.

Diagnosis

Diagnosis of acute limb ischaemia is primarily clinical, supported by imaging studies. Doppler ultrasound can assess blood flow, while angiography can visualize the site and extent of the blockage.

Treatment

The primary goal of treatment is to restore blood flow to the affected limb as quickly as possible. Treatment options include:

• Thrombolysis: Administration of clot-dissolving medications.
• Surgical embolectomy: Surgical removal of the embolus or thrombus.
• Bypass surgery: Creating a new route for blood flow around the blockage.

Prognosis

The prognosis of acute limb ischaemia depends on the speed of diagnosis and treatment. Delayed treatment can lead to limb amputation and other serious complications.

Related Pages

• Peripheral artery disease
• Chronic limb-threatening ischaemia
• Vascular surgery

Gallery

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  Arterial thrombosis causing cyanosis
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  Acute occlusion of the axillary artery
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  Angiograph before and after thrombolytic therapy