Synopsis
Start safe temporising treatment and secure immediate vascular decision-making without allowing tests, contraindications or transfer logistics to waste limb viability.
- Contact the on-call vascular service immediately, map sensory and motor loss, and treat any weakness or sensory loss beyond the toes as an immediately threatened Rutherford IIb limb.
- Give intravenous unfractionated heparin promptly unless active major bleeding, a critical bleeding site or current or previous immune HIT contraindicates it; seek urgent vascular and haematology advice for an alternative.
- Do not let CTA, duplex, ABPI, blood results or transfer administration delay emergency revascularisation; profound anaesthesia, paralysis and absent arterial plus venous signals require senior confirmation of irreversible Rutherford III.
Key red flags
New motor weakness indicates Rutherford IIb immediate threat and requires emergency revascularisation rather than a routine referral or prolonged diagnostic sequence.
Sensory loss beyond the toes, rest pain with progressing numbness or worsening findings during transfer require real-time vascular escalation.
Profound anaesthesia, complete paralysis or rigor with absent arterial and venous Doppler signals suggests irreversible Rutherford III damage and dangerous reperfusion.
Active major haemorrhage, suspected intracranial bleeding, major recent brain, spinal or eye surgery, or current or previous immune HIT contraindicates routine UFH and requires an urgent specialist alternative.
Severe chest or back pain, haemodynamic instability or bilateral limb findings raises an aortic catastrophe needing simultaneous vascular and resuscitation pathways.
No weakness with no sensory loss or numbness confined to the toes indicates a marginally threatened limb that remains salvageable if treated promptly.
Sensory loss beyond the toes, rest pain and especially mild to moderate motor weakness indicate immediate threat requiring emergency revascularisation.
Profound anaesthesia, paralysis or rigor, absent capillary refill and absent arterial and venous Doppler signals indicate likely irreversible damage.
Active clinically important haemorrhage, suspected intracranial bleeding or a recent operation at a critical bleeding site makes routine heparin unsafe and needs senior discussion.
Previous immune heparin-induced thrombocytopenia or new thrombosis with an unexplained platelet fall requires avoidance of heparin and urgent specialist anticoagulant selection.
Shock, arrhythmia, acidosis, hyperkalaemia, oliguria or bilateral ischaemia increases immediate mortality risk and requires resuscitation alongside vascular decision-making.
Increasing analgesia requirement, spreading numbness or new weakness while awaiting transport must be reported directly to the accepting vascular clinician rather than merely documented.
Investigation priorities
Grade limb viability and determine how much diagnostic delay is permissible.
Management branches
Acute pain, coldness, pulse or Doppler loss, paraesthesia or weakness creates suspected acute limb ischaemia.
- Call the on-call vascular service immediately, state symptom onset and Rutherford sensory, motor and Doppler findings, and agree destination before routine investigations create delay.
- Give titrated analgesia, establish intravenous access, screen rapidly for active bleeding and previous immune HIT, then give the licensed intravenous UFH regimen when safe.
Active major bleeding, a critical bleeding site or current or previous immune HIT makes routine UFH unsafe.