Examkin

Question

Difficulty: HardCardiothoracic and Vascular Surgery

A 68-year-old man is evaluated in the surgical step-down unit on postoperative day 6 following a coronary artery bypass grafting procedure. He reports worsening retrosternal pain and subjective chills over the past 24 hours. The pain is sharp, is exacerbated by deep breathing, and feels distinct from his initial postoperative discomfort. His temperature is 38.9∘C38.9^\circ\text{C} (102.0∘F102.0^\circ\text{F}), blood pressure is 105/65 mmHg105/65\text{ mmHg}, pulse is 112/min112/\text{min}, and respirations are 22/min22/\text{min}. On physical examination, the sternal incision is erythematous with a small amount of cloudy, serosanguineous drainage. Firm palpation of the sternum elicits a clicking sensation and palpable movement of the bony edges when the patient coughs. The lungs are clear to auscultation bilaterally. Laboratory studies show a leukocyte count of 18,500/mm318,500/\text{mm}^3 with 85%85\% neutrophils. A chest radiograph demonstrates a widened mediastinum and a new, small left-sided pleural effusion. Which of the following is the most appropriate next step in management?

  1. Prompt surgical exploration and sternal debridementAnswer
  2. B
    Initiation of empiric intravenous antibiotics and daily bedside wound packing
  3. C
    Computed tomography angiography of the chest
  4. D
    Administration of intravenous furosemide and noninvasive positive pressure ventilation
  5. E
    Sputum culture and empiric therapy for hospital-acquired pneumonia

Answer

The most appropriate next step is prompt surgical exploration and sternal debridement.
The correct answer is prompt surgical exploration and sternal debridement. The patient's presentation is classic for acute mediastinitis, a dreaded complication following cardiac surgery involving a median sternotomy. It typically presents within 14 days postoperatively with fever, tachycardia, chest pain, and purulent wound drainage. The hallmark physical exam finding is sternal instability, often described as a 'clicking' sensation or palpable movement of the sternal edges upon coughing. Chest radiography frequently shows a widened mediastinum. Because acute mediastinitis is a deep space infection with a mortality rate of 10% to 50%, medical therapy with antibiotics alone is inadequate. Definitive management requires emergent surgical exploration, radical debridement of necrotic bone and tissue, continuous mediastinal irrigation, and eventual primary or flap closure, alongside broad-spectrum intravenous antibiotics.

Step-by-Step Solution

1
Analyze the timing and clinical signs of the postoperative fever.
The patient is on postoperative day 6 with high fever, marked leukocytosis, purulent wound drainage, and sternal clicking.
Identifying the specific localizing signs (sternal instability) helps differentiate between common postoperative complications like pneumonia and a deep wound infection.
2
Synthesize the physical exam and imaging findings to establish a diagnosis.
The combination of sternal instability, infectious symptoms, and a widened mediastinum on chest radiograph confirms the diagnosis of acute mediastinitis.
Acute mediastinitis is a severe complication of median sternotomy that typically presents within 14 days of surgery.
3
Determine the definitive management for the established diagnosis.
The patient requires immediate return to the operating room for surgical exploration, debridement, and continuous irrigation.
Medical management alone is associated with an unacceptably high mortality rate; deep tissue source control is mandatory.

Key Concept

Acute mediastinitis post-sternotomy is diagnosed clinically (fever, purulent drainage, sternal instability) and requires emergent surgical exploration, debridement, and broad-spectrum antibiotics.
Rate this question

Topics

Cardiothoracic and Vascular Surgery

More questions from this topic