Definitive Management

Management of the patient is based on Rutherford’s classification:

Category I

These patients have a viable limb. They should be admitted, given analgesia and oxygen and heparinised (infusion).

There is no good evidence to support the use of low-molecular-weight heparin in this situation, and it is more difficult to adjust if interventions are required.

Formal imaging (angiogram, MR angiogram, CT angiogram or arterial duplex depending on local resources) should then be arranged within normal working hours to plan definitive treatment.

Category IIa

These patients have a threatened limb. They should be given oxygen, analgesia and heparin.

Ideally, they should have immediate imaging, to guide operative (or endovascular) intervention.

In some cases, where there is minimal sensory loss only, the patient may be managed conservatively overnight, and imaging obtained the following day.

Category IIb

These patients have a threatened limb and cannot wait overnight. They should be given oxygen, analgesia and heparin. If circumstances allow, it may be possible to obtain imaging prior to theatre but this should not delay intervention. The patient needs urgent revascularisation, either operatively or with thrombolysis. Imaging may be acquired whilst the patient is in theatre.

In a patient with a clear history for embolus (and a source of embolus) and a normal contralateral limb, an embolectomy may be performed under local anaesthesia. The advantage of this is that local anaesthesia is better tolerated by elderly patients with cardiac comorbidity. The disadvantage is that if a simple embolectomy is unsuccessful and a more extensive procedure is required, it may be necessary to convert to general anaesthesia. In all cases, an anaesthetist should be present to manage the patient medically during the procedure. On-table imaging should be available and the whole leg prepared and draped.

Following revascularisation, the limb may swell and the need for fasciotomy should always be considered.

Category III

These patients have irreversible ischaemia and the limb is not salvageable. Revascularisation in this situation is likely to kill the patient, due to the massive release of potassium, creatine kinase, myoglobin, lactate and oxygen-free radicals from the ischaemic tissue which can cause renal failure, myocardial toxicity and multi-organ failure. The options are either amputation or palliation.

In an acute scenario, with evidence of infection, a ‘guillotine amputation’ may be performed to allow rapid removal of necrotic/infected tissue, with a definitive amputation at a later date when the patient is more stable and infection has been treated.

It is vital to recognise those patients in which an ischaemic limb is part of the process of dying, and not subject them to unnecessary and futile interventions.