Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.
2 min synopsisUK scopeSources checked 12 Sept 2026Clinical review pending
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Threatened limb
New motor or sensory loss indicates a threatened limb whose salvage depends on rapid restoration of flow.
Action: Call vascular surgery immediately, give initial intravenous unfractionated heparin unless contraindicated, provide analgesia and resuscitation, and move directly to the fastest anatomically effective revascularisation pathway.
Synopsis
Select an urgent revascularisation strategy for acute limb ischaemia while matching technique, anatomy, limb threat and bleeding risk.
Classify limb viability before choosing a technique: Rutherford IIb neurological deficit needs urgent revascularisation, whereas fixed mottling and profound paralysis suggest irreversible class III injury.
Give initial intravenous unfractionated heparin for acute limb ischaemia unless bleeding or another contraindication prevents it, but do not let anticoagulation delay definitive reperfusion.
Catheter-directed thrombolysis delivers a fibrinolytic intra-arterially into thrombus; systemic intravenous thrombolysis is not the routine treatment for acute limb ischaemia.
Key red flags
Motor weakness, profound anaesthesia or fixed mottling requires immediate senior vascular assessment because the limb may be immediately threatened or irreversible.
Active bleeding, recent major surgery, recent intracranial haemorrhage or another major lysis contraindication may exclude catheter-directed thrombolysis and changes the procedural choice.
Compartment tension or systemic acidosis and hyperkalaemia after flow restoration signals reperfusion injury requiring simultaneous critical-care treatment.
Immediately threatened limb
New weakness, sensory loss beyond the toes and absent arterial Doppler signals indicate Rutherford IIb ischaemia requiring immediate revascularisation.
Irreversible ischaemia
Profound anaesthesia, paralysis, fixed mottling and muscle rigor suggest class III injury where reperfusion may release lethal metabolites without salvaging tissue.
Lysis bleeding risk
Recent intracranial bleeding, active haemorrhage, major recent surgery or uncontrolled hypertension can make thrombolysis unsafe and redirect treatment.
Investigation priorities
01
Bedside Rutherford classificationFirst step
Determine whether imaging time is available and how urgently flow must be restored.
Management branches
Immediate pathwayClassify and protect the limb
A patient presents with sudden pain, pallor, coldness, sensory change or weakness suggesting acute limb ischaemia.
Perform simultaneous ABCDE assessment and a documented bilateral pulse, Doppler, sensory and motor examination that assigns Rutherford class.
Contact vascular surgery immediately, give analgesia and initial intravenous unfractionated heparin unless contraindicated, and keep the patient nil by mouth.
Key medicines
Unfractionated heparinGive an intravenous bolus of 5,000 IU or 70–100 IU/kg, followed by continuous intravenous infusion adjusted to activated clotting time or APTT using the local preparation and infusion nomogram.Withhold or modify for active bleeding, heparin-induced thrombocytopenia or another major contraindication. Therapeutic systemic heparinisation during catheter thrombolysis increases bleeding and is not a routine substitute for the local low-dose catheter-sheath protocol.
Intra-arterial alteplasePeripheral arterial use is specialist and off-label in the UK; prescribe a continuous intra-arterial catheter infusion with concentration, hourly rate, maximum cumulative dose, review interval and stop point explicitly defined by the local vascular-interventional protocol.Do not give as routine systemic intravenous thrombolysis for limb ischaemia. Exclude major bleeding contraindications, monitor access site, neurology, haemoglobin, coagulation and protocol fibrinogen, and stop immediately for major haemorrhage or suspected intracranial bleeding.
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 12 Sept 2026; clinical approval remains outstanding.