Key Points
- Use the highest‑yield diagnostic test early; do not let testing delay time‑critical therapy.
- Set objective targets and reassess frequently.
- Plan definitive source control or disease‑specific therapy when indicated; document follow‑up and patient education.
Algorithm
- Start systemic heparin immediately; assess Rutherford grade (I, IIa, IIb, III).
- Obtain CTA if time allows and limb viable; otherwise go directly to OR.
- Choose revascularization: IIa → thrombolysis; IIb → urgent surgery; nonviable → amputation.
- Post‑revascularization: monitor compartment pressures and renal injury; secondary prevention and anticoagulation.
Clinical Synopsis & Reasoning
Sudden limb pain, pallor, pulselessness, paresthesia, paralysis, and poikilothermia require immediate systemic heparin, urgent imaging (CTA) when viable, and revascularization (embolectomy, thrombectomy, or thrombolysis) based on Rutherford grade.
Treatment Strategy & Disposition
Stabilize ABCs. Initiate guideline‑concordant first‑line therapy with precise dosing and continuous monitoring. Escalate to advanced/procedural interventions based on explicit failure criteria. Define ICU, step‑down, and ward disposition triggers; involve specialty teams early.
Epidemiology / Risk Factors
- Risk varies by comorbidity and precipitants; see citations for condition‑specific data.
Investigations
| Test | Role / Rationale | Typical Findings | Notes |
|---|---|---|---|
| Bedside Doppler/ABI | Initial assessment | Absent signals | Helps grade severity |
| CTA with runoff (if limb viable) | Anatomic roadmap | Level of occlusion; embolus vs thrombosis | Avoid delay if limb immediately threatened |
| Labs including CK/lactate | Severity/reperfusion risk | Elevated with prolonged ischemia | Plan fasciotomy if needed |
Pharmacology
| Medication/Intervention | Mechanism | Onset | Role in Therapy | Limitations |
|---|---|---|---|---|
| Unfractionated heparin bolus 80 U/kg → infusion | Anticoagulant | Immediate | Prevents propagation | Monitor aPTT/anti‑Xa |
| Catheter‑directed thrombolysis (selected) | Thrombolytic | Hours | For Rutherford IIa, thrombosis | Bleeding risk |
| Open embolectomy/thrombectomy/bypass | Definitive | Immediate | For IIb or embolus | Consider fasciotomy for reperfusion |
Prognosis / Complications
- Outcome depends on timeliness of diagnosis and definitive therapy; monitor for complications.
Patient Education / Counseling
- Provide red‑flag education, adherence guidance, and explicit return precautions; arrange timely specialty follow‑up.
References
- SVS/ESVS guidelines on acute limb ischemia — Link