## Classification and Management of Acute Limb Ischemia ### Rutherford Classification of Acute Limb Ischemia | Stage | Viability | Sensory Loss | Motor Loss | Muscle Tenderness | |-------|-----------|--------------|------------|-------------------| | I (Viable) | Viable | None | None | None | | IIa (Threatened) | Salvageable | Mild/Marginal | None | None | | IIb (Threatened) | Salvageable | Moderate/Severe | Mild/Moderate | Yes | | III (Irreversible) | Unsalvageable | Severe (anesthetic) | Severe (paralysis) | Severe (rigor) | **Key Point:** Stage IIb ischemia is characterized by moderate-to-severe sensory loss AND mild-to-moderate motor weakness — the limb is threatened but still potentially salvageable with urgent revascularization. Stage III (irreversible) is defined by profound anesthesia, complete paralysis, and muscle rigor indicating established myonecrosis. ### Why Option A is FALSE (the EXCEPT answer) **High-Yield:** The stem states the patient has sensory loss and motor weakness — this correctly maps to **Stage IIb** (threatened, salvageable). However, Option A claims this indicates "Stage IIb ischemia **with tissue loss**." This is factually incorrect. Stage IIb is a **threatened** limb — tissue loss (myonecrosis/gangrene) is the hallmark of **Stage III (irreversible)** ischemia, not Stage IIb. Equating Stage IIb with tissue loss misrepresents the Rutherford classification and is the false statement among the options. ### Why the Other Options Are TRUE **Option B — TRUE:** Immediate anticoagulation with IV heparin (80 U/kg bolus, then 18 U/kg/hr infusion) is mandatory in ALL stages of acute limb ischemia to prevent thrombus propagation, even before definitive revascularization. This is a cornerstone of management per Rutherford's Vascular Surgery and TASC II guidelines. **Option C — TRUE:** Fogarty catheter embolectomy is the preferred first-line intervention for acute embolic occlusion (as in this patient with atrial fibrillation), particularly when the limb is threatened and there is a clear embolic source. This is well-established in surgical textbooks (Bailey & Love, Schwartz's Principles of Surgery). **Option D — TRUE (as a general principle):** Thrombolytic therapy is indeed contraindicated when the limb shows signs of irreversible ischemia (Stage III — fixed mottling, paralysis, rigor). In this patient the clinical picture is Stage IIb (not irreversible), so thrombolysis would actually be an option; however, the statement as written correctly identifies the contraindication principle for irreversible ischemia, making it a true statement in the context of the question. **Clinical Pearl:** The Rutherford classification is the standard framework for staging acute limb ischemia. Stage IIb = threatened but salvageable (sensory + motor loss); Stage III = irreversible (tissue loss, gangrene). Confusing these two stages is a common exam trap. *(Reference: Rutherford's Vascular Surgery, 8th edition; TASC II Guidelines for Peripheral Arterial Disease)*
Sign up free to access AI-powered MCQ practice with detailed explanations and adaptive learning.