Medicines for Acute limb ischaemia

What it is

Acute limb ischaemia is a sudden and severe reduction or blockage of the blood supply to an arm or (more commonly) a leg, which threatens the survival of the limb. It is a medical emergency, because the tissues of the limb are rapidly deprived of oxygen, and without prompt treatment to restore blood flow, the limb can be permanently damaged and, in severe cases, lost. It is usually caused by a sudden blockage of an artery — most often by a blood clot that has either travelled from elsewhere (such as from the heart, particularly with an irregular heart rhythm like atrial fibrillation) and lodged in the limb artery (an embolism), or formed on top of already-narrowed arteries (thrombosis); it can also follow injury. The classic features are often summarised as the "six Ps": Pain (sudden and severe), Pallor (the limb looks pale or mottled), Pulselessness (no pulse felt in the limb), Perishing cold (the limb feels cold), Paraesthesia (pins and needles or numbness), and Paralysis (weakness or inability to move the limb) — the later features (numbness and weakness) indicate a more advanced, urgent situation. Because the window to save the limb is limited, sudden onset of a painful, pale, cold, pulseless limb needs immediate emergency assessment.

How it is treated

Acute limb ischaemia is a surgical emergency requiring immediate hospital assessment and treatment, as the chance of saving the limb depends on restoring blood flow quickly. Anyone with a suddenly painful, pale, cold, numb or weak limb should seek emergency care without delay. In hospital, the limb and circulation are assessed urgently (including how advanced the ischaemia is), and treatment is started promptly — this usually includes giving a blood-thinning medicine (such as heparin) straight away to prevent the clot extending, along with urgent measures to restore blood flow. The specific treatment depends on the cause and severity and is decided by vascular specialists: options include surgery to remove the clot (embolectomy), techniques to dissolve or remove the clot, angioplasty or bypass to restore flow, and, where the limb is already too severely damaged, sometimes amputation. Speed is critical, as the longer the blood flow is cut off, the greater the tissue damage. After the emergency is treated, the underlying cause (such as an irregular heart rhythm or arterial disease) is identified and managed to prevent it happening again, often including long-term blood-thinning or antiplatelet treatment and cardiovascular risk reduction. The overriding message is that acute limb ischaemia is a limb-threatening emergency — a suddenly painful, pale, cold, pulseless limb needs immediate emergency care, as prompt treatment to restore blood flow can save the limb.