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Zorluk: Çok zorCardiothoracic and Vascular Surgery

A 75-year-old woman is evaluated in the emergency department for severe right leg pain. She was found on the floor of her apartment after a fall and was last known to be in her usual state of health 36 hours ago. Medical history is significant for hypertension, prior myocardial infarction, and paroxysmal atrial fibrillation for which she has not been taking anticoagulation. Her temperature is 37.1°C (98.8°F), blood pressure is 142/86 mmHg, and heart rate is 112/min and irregularly irregular. On physical examination, the right lower extremity is pale, cold to the touch, and mottled from the toes extending up to the mid-thigh. There is complete absence of sensation below the right knee. The patient is unable to move her right ankle or toes, and the calf muscles are remarkably firm and rigid to palpation. Handheld Doppler ultrasound evaluation reveals absent arterial and venous signals in the right popliteal, dorsalis pedis, and posterior tibial vessels. Which of the following is the most appropriate next step in management?

  1. Primary above-knee amputationCevap
  2. B
    Emergent open surgical embolectomy
  3. C
    Catheter-directed intra-arterial thrombolysis
  4. D
    Prophylactic four-compartment fasciotomy
  5. E
    Computed tomography angiography of the lower extremities

Cevap

The most appropriate next step in management is primary above-knee amputation.
This patient's presentation is consistent with Rutherford Category III (irreversible) acute limb ischemia. Acute limb ischemia typically presents with the classic '6 Ps': pain, pallor, pulselessness, paresthesia, paralysis, and poikilothermia (coolness). The severity is categorized to guide management. The hallmarks of Category III (irreversible) ischemia include profound sensory loss (anesthesia), profound motor deficit (paralysis), rigid muscles (indicating muscle necrosis and rigor), and the absence of both arterial and venous Doppler signals. In this patient, the 36-hour symptom duration, complete paralysis, rigid calf muscles, and absent venous flow unequivocally indicate a non-viable limb. The most appropriate next step in management for an irreversibly ischemic limb is primary amputation (in this case, above-knee, given the extent of ischemic changes up to the mid-thigh). Revascularization (via embolectomy, bypass, or thrombolysis) of a dead limb is strictly contraindicated. Re-establishing blood flow to necrotic muscle tissue results in reperfusion syndrome, which is characterized by the massive release of intracellular contents—potassium, myoglobin, lactic acid, and inflammatory mediators—into the systemic circulation. This can rapidly precipitate fatal cardiac arrhythmias, severe metabolic acidosis, and myoglobinuric acute kidney injury.

Adım Adım Çözüm

1
Analyze the patient's history and physical examination findings.
The patient has 36 hours of limb ischemia with a pale, cold, mottled leg, anesthesia, paralysis, rigid calf muscles, and absent arterial and venous Doppler signals.
To classify the severity of acute limb ischemia based on the Rutherford criteria.
2
Classify the severity of acute limb ischemia.
The limb is classified as Rutherford Category III (irreversible ischemia).
The presence of rigid muscles (rigor mortis of muscle tissue), complete anesthesia, profound paralysis, and absent venous Doppler signals confirm that the tissue is non-viable and irreversibly damaged.
3
Determine the appropriate management for Category III acute limb ischemia.
Primary amputation is required.
Revascularization of necrotic muscle tissue is contraindicated because it will cause reperfusion syndrome (massive release of potassium, myoglobin, and acid), which can rapidly lead to cardiac arrest and acute kidney injury.

Anahtar Kavram

Management of irreversible acute limb ischemia (Rutherford Category III) requires primary amputation due to the high risk of fatal reperfusion syndrome if revascularization is attempted.
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Cardiothoracic and Vascular Surgery

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