EM · Acute limb ischaemia
Acute limb ischaemia (the emergency of the 6 Ps)
Also known as ALI · Acute arterial occlusion · The 6 Ps · Acute leg ischaemia
Acute limb ischaemia — the 6 Ps (pain, pallor, pulseless, paraesthesia, paralysis, perishing cold), the embolic versus the thrombotic cause, the Rutherford classification (viable through irreversible), the immediate anticoagulation with unfractionated heparin, the definitive management (the Fogarty embolectomy for the embolic, the catheter-directed thrombolysis for the thrombotic), the 6-hour window for the limb salvage, and the fasciotomy for the reperfusion. ACEM-primary, globally tagged.
Checked against its sources on 3 Sept 2026
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Target exams
Red flags
- The 6-hour window — an acutely ischaemic limb that is not revascularised within 6 hours may become irreversibly ischaemic and need an amputation
- Paralysis and paraesthesia (not just pain) signal a threatened limb that needs the immediate revascularisation, not just the anticoagulation
- The unfractionated heparin is given immediately — do not wait for the surgical assessment to start the anticoagulation
- Atrial fibrillation is the commonest source of the embolus — check the rhythm and anticoagulate long-term to prevent the recurrence
- A fasciotomy may be needed after the revascularisation — the reperfusion of the ischaemic limb produces a compartment syndrome
Meet the patient
A 71-year-old woman with chronic atrial fibrillation is brought in three hours after her left leg "went dead" at rest. The leg is white and perishingly cold below the knee, the popliteal and pedal pulses are gone, and she cannot dorsiflex her toes against gravity. The Doppler finds no arterial signal in the foot but a clear venous one. You reach for the heparin before you reach for the phone — this is a Rutherford IIb limb, and it goes to theatre, not the scanner.[3][6][2]
Two facts decide her next hour, and they decide every acute limb ischaemia: how threatened is the limb? (the 6 Ps, graded into a Rutherford category) and embolus or thrombosis? (the cause that picks the operation). Hold those two questions and the pathway below slots into place.[3]
References16ShowHide
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- [2]Brewster DC. Acute peripheral arterial occlusion Cardiol Clin, 1991.PMID 1833055
- [3]Björck M, Earnshaw JJ, Acosta S, et al. Editor's Choice - European Society for Vascular Surgery (ESVS) 2020 Clinical Practice Guidelines on the Management of Acute Limb Ischaemia Eur J Vasc Endovasc Surg, 2020.PMID 31899099
- [4]The STILE Investigators. Results of a prospective randomized trial evaluating surgery versus thrombolysis for ischemia of the lower extremity. The STILE trial Ann Surg, 1994.PMID 8092895
- [5]Ouriel K, Veith FJ, Sasahara AA A comparison of recombinant urokinase with vascular surgery as initial treatment for acute arterial occlusion of the legs. Thrombolysis or Peripheral Arterial Surgery (TOPAS) Investigators N Engl J Med, 1998.PMID 9545358
- [6]Rutherford RB, Baker JD, Ernst C, et al. Recommended standards for reports dealing with lower extremity ischemia: revised version J Vasc Surg, 1997.PMID 9308598
- [7]Norgren L, Hiatt WR, Dormandy JA, et al. Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II) J Vasc Surg, 2007.PMID 17223489
- [8]Conte MS, Bradbury AW, Kolh P, et al. Global Vascular Guidelines on the Management of Chronic Limb-Threatening Ischemia Eur J Vasc Endovasc Surg, 2019.PMID 31182334
- [9]Darwood R, Berridge DC, Kessel DO, et al. Surgery versus thrombolysis for initial management of acute limb ischaemia Cochrane Database Syst Rev, 2018.PMID 30095170
- [10]McNally MM, Univers J. Acute Limb Ischemia Surg Clin North Am, 2018.PMID 30243449
- [11]Gilliland C, Shah J, Martin JG, et al. Acute Limb Ischemia Tech Vasc Interv Radiol, 2017.PMID 29224661
- [12]Doelare SAN, Koedam TWA, Ebben HP, et al. Catheter Directed Thrombolysis for Not Immediately Threatening Acute Limb Ischaemia: Systematic Review and Meta-Analysis Eur J Vasc Endovasc Surg, 2023.PMID 36608784
- [13]Bagge JD, Eldrup N, Resch T, et al. [Acute limb ischaemia]. Ugeskr Laeger, 2025.PMID 40025885
- [14]Labbe R, Lindsay T, Walker PM. The extent and distribution of skeletal muscle necrosis after graded periods of complete ischemia J Vasc Surg, 1987.PMID 3039184
- [15]Gourgiotis S, Villias C, Germanos S, et al. Acute limb compartment syndrome: a review J Surg Educ, 2007.PMID 17574182
- [16]Turel M, Kumar PP, Stephen E, et al. A 10-year experience of managing acute limb ischaemia in India Natl Med J India, 2008.PMID 19691217