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Post-Cardiac Surgery Mediastinitis — SCE Infectious Diseases MCQ

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ModerateHealthcare-Associated InfectionsPost-Cardiac Surgery MediastinitisSCE Infectious Diseases

A 50-year-old man develops a deep sternal wound infection 3 weeks after CABG surgery. The wound is dehisced with purulent drainage and exposed sternal wires. CT shows pre-sternal collection communicating with the mediastinum. The surgical team asks the ID team about antibiotic choice. What empirical regimen covers the likely organisms?

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Correct answer: C — IV Vancomycin (MRSA cover) plus IV Piperacillin/Tazobactam

Deep sternal wound infection/mediastinitis after cardiac surgery is polymicrobial in approximately 40% of cases. Pathogens include: S. aureus (including MRSA — most common), coagulase-negative staphylococci, Gram-negative bacilli (E. coli, Klebsiella, Pseudomonas), and occasionally Candida. Empirical coverage should include MRSA (Vancomycin — as post-cardiac surgery MRSA rates are significant) plus Gram-negative cover (Piperacillin/Tazobactam or Meropenem). Definitive therapy is directed by deep tissue cultures. Surgical debridement ± VAC therapy ± muscle flap reconstruction is essential.

Reference: https://www.nice.org.uk/guidance/conditions-and-diseases/infections