Tempo
seconds–minutes (embolus, dissection) vs hours–days (thrombosis, infection)
Chest, back, or abdominal pain (dissection, AAA)
AF, recent MI, aneurysm, bypass graft, cath access
Trauma, crush, lithotomy, anticoagulation, malignancy
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← All presentations
Acute Limb Ischemia
A cold pulseless limb is a clock — and sometimes a dissected aorta.
Your objective: explain the approach, recognize important warning signs, then test your recall.
Abbreviations explained
- ACS
- Acute coronary syndrome
- OMI
- Occlusion myocardial infarction
- ECG
- Electrocardiogram
- PE
- Pulmonary embolism
- POCUS
- Point-of-care ultrasound
- QTc
- QT interval corrected for heart rate
- LBBB
- Left bundle branch block
- RBBB
- Right bundle branch block
- hs-cTn
- High-sensitivity cardiac troponin
- CTA
- Computed tomography angiography
- ICU
- Intensive care unit
Filter
The jobA cold pulseless limb is a clock — and sometimes a dissected aorta.
- Exam first: pulses, Doppler, comparison with the other limb, and a motor/sensory map.
- Chest or back pain with a pulse deficit is dissection until CTA says otherwise — do not anticoagulate blindly.
- Classic ALI: unfractionated heparin and an immediate vascular call; imaging must not delay a clearly threatened limb.
- Pain out of proportion after reperfusion or crush is compartment syndrome — fasciotomy, not another scan.
Acute limb ischemia is a vascular emergency: the six Ps (pain, pallor, pulselessness, poikilothermia, paresthesia, paralysis) mark time-to-muscle.
Embolus, thrombosis of a diseased vessel, aortic dissection into a limb, phlegmasia, and necrotizing infection can share the stage. Do not wait for an ABI when the exam is classic — heparin, vascular surgery, and CTA of the aorta-to-runoff as the story dictates.
Embolic or thrombotic acute limb ischemia Critical
Key: Sudden pain, pallor, pulselessness — Rutherford threatened limb needs revascularization now. Heparin unless dissection is the leading diagnosis.
Aortic dissection into a limb Critical
Key: Chest/back pain + pulse deficit or a cold arm/leg — CTA aorta first; anticoagulating this as a simple embolus can be lethal.
Phlegmasia cerulea dolens / massive DVT Critical
Key: Cyanotic swollen limb, often malignant or post-op — anticoagulation ± thrombolysis/thrombectomy; watch for venous gangrene.
Compartment syndrome Critical
Key: Pain on passive stretch after trauma, crush, or reperfusion — compartment pressures support but do not override clinical diagnosis; fasciotomy.
Necrotizing soft-tissue infection Critical
Key: Pain out of proportion, rapid spread, crepitus, or shock — surgery now.
Blue toe / cholesterol emboli after cath Emergent
Key: Livedo and intact pulses after an aortic procedure — do not miss ongoing aortic source.
Chronic PAD / claudication flare Common
Key: Exertional calf pain that resolves with rest, pulses diminished but tissue viable — outpatient vascular pathway if no rest pain or tissue loss.
Tick what your patient has — the banner updates as you go.
Pulses and Doppler in both limbs; ankle-brachial index only if it will not delay care
Skin
pallor vs cyanosis vs mottling vs crepitus
Motor and sensory — paralysis means muscle is dying
Heart
AF, murmur; abdomen: AAA; chest: BP in both arms
Passive stretch pain of the compartments
Bedside
- ECG (AF, ischemia); bilateral arm BP
- Handheld Doppler; POCUS for AAA and dissection flap if trained
- Glucose, lactate
Labs
- CBC, coagulation, CK, creatinine, type & screen
- Cultures if infection/shock
Imaging
- CTA aorta-to-runoff when dissection or embolic shower is possible
- Duplex if the diagnosis is uncertain and the limb is viable
- Do not delay a threatened limb for perfect pictures
Medication safety reminder
Use this as a first-pass prompt; verify all medications, doses, concentrations, contraindications, weight, pregnancy status, and local protocols before administration.
Check indication, allergy, route, renal/hepatic risk, interactions, monitoring, and local formulary.
Discharge
- Chronic claudication without rest pain or tissue threat, intact Doppler, reliable vascular follow-up.
Admit (vascular)
- Viable but symptomatic ischemia, phlegmasia on anticoagulation, post-cath blue toe, infection needing IV therapy.
Emergency revascularization / OR / ICU
- Threatened or irreversible ALI, dissection, compartment syndrome, necrotizing infection.
Use objective reassessment and the local pathway.
Before the next decision · reassess and hand over
Use these learning prompts with the presentation’s pathway. They are not discharge criteria.
- Reassess: compare symptoms, observations and examination with the initial assessment and response to treatment.
- Warning signs for Acute Limb Ischemia:
- Pulseless, pale, or paralyzed limb
- Chest or back pain with a pulse deficit
- Pain on passive stretch after trauma or reperfusion
- Crepitus, bullae, or shock with a soft-tissue source
- Cyanotic swollen limb (phlegmasia)
- Rest pain in a vasculopath with tissue loss
- Reconsider: check unresolved findings and alternative explanations, including the pitfalls below.
- Escalate: communicate deterioration, uncertainty or needs beyond the current setting.
- Plan the transition: identify outstanding results, responsibility for follow-up, patient understanding and specific return advice.
Clinical Pearls
- Six Ps are a clock, not a checklist to complete before calling vascular.
- Pulse deficit + chest or back pain = aorta, not a femoral embolus in isolation.
- Heparin unless dissection leads; imaging must not delay a threatened limb.
- Passive stretch pain after crush or reperfusion is compartment syndrome.
Pitfalls
- Waiting for ABI or formal angiography while the limb dies.
- Heparin for “embolus” that is really a type A dissection.
- Calling cellulitis when the pain is out of proportion (nec fasc or compartment).
- Irreversible ischemia still needs source control and often amputation planning — do not send home a dead limb.
- Reperfusion without watching compartments produces a second disaster.
PRACTICE REFRESHER
Rapid recall
Test your first action and the dangerous diagnoses before revealing the answer.
01 · First move
Before you scroll, what needs to happen first?
Exam first: pulses, Doppler, comparison with the other limb, and a motor/sensory map.
02 · Immediate threats
Name at least two diagnoses that cannot wait.
Embolic or thrombotic acute limb ischemia · Aortic dissection into a limb · Phlegmasia cerulea dolens / massive DVT
PRIVATE TO THIS DEVICE
Your learning note
Capture a weak point, a teaching pearl, or a question to take to your next shift.
Review schedule starts when marked reviewed
Foundational references below. No separate topic-specific guideline check is recorded here.
- Rosen’s Emergency Medicine, 10th ed. (2023) — peripheral vascular and aortic disease
- AHA/ACC PAD and aortic disease guidance
- SVS acute limb ischemia recommendations