What is the recommended treatment for mediastinitis?

Treatment of Mediastinitis

Treatment of mediastinitis depends critically on the underlying etiology—fungal mediastinitis requires antifungal therapy with amphotericin B followed by itraconazole, while post-surgical bacterial mediastinitis requires broad-spectrum antibiotics targeting staphylococci (particularly MRSA) combined with aggressive surgical debridement. 1

Fungal Mediastinitis (Histoplasmosis-Related)

Granulomatous Mediastinitis

This represents active inflammation rather than fibrotic disease and is potentially treatable with antifungals. 2

• For severe obstructive complications: Initiate amphotericin B 0.7-1.0 mg/kg/day as first-line therapy 2, 1
• After clinical improvement: Transition to itraconazole 200 mg once or twice daily for 6-12 weeks total duration 2, 1
• For mild to moderate cases: Itraconazole 200 mg once or twice daily for 6-12 weeks may be used as initial therapy 2
• Adjunctive corticosteroids: Prednisone 0.5-1.0 mg/kg daily (maximum 80 mg) in tapering doses over 1-2 weeks for severe airway obstruction 2, 1
• Critical caveat: When corticosteroids are used, itraconazole must be given concurrently to prevent disseminated histoplasmosis from steroid-induced immunosuppression 2, 3

Fibrosing Mediastinitis

This represents chronic fibrotic disease with a progressive, often fatal course. 2

• Antifungal treatment is generally NOT indicated as most authorities believe it does not ameliorate outcomes 2, 1
• Exception: If clinical findings cannot differentiate fibrosing from granulomatous mediastinitis (elevated complement fixation titers, elevated ESR, acute inflammatory features), consider a 12-week trial of itraconazole 200 mg once or twice daily 2, 1
• Do not expect response in true fibrosing mediastinitis; only continue beyond 12 weeks if clear radiographic improvement in obstruction is documented 2
• Surgical intervention should be avoided 2
• Intravascular stents are recommended for selected patients with pulmonary vessel obstruction 1

Common pitfall: Failing to distinguish between granulomatous (treatable) and fibrosing (not treatable with antifungals) mediastinitis leads to inappropriate prolonged antifungal therapy that will not benefit the patient. 1, 3

Post-Surgical/Post-Traumatic Bacterial Mediastinitis

This most commonly follows cardiac surgery, with staphylococci as dominant pathogens. 4, 5

Antibiotic Selection

For MRSA-associated mediastinitis:

• Primary treatment: Vancomycin 30-60 mg/kg/day IV in 2-4 divided doses 1
• Alternatives: Teicoplanin, linezolid, or daptomycin 1
• Linezolid dosing in renal dysfunction: Maintain serum trough concentration between 2-7 μg/mL with therapeutic drug monitoring 6

For polymicrobial infections (esophageal perforation, descending necrotizing mediastinitis):

• Broad-spectrum beta-lactams alone or combined with metronidazole to cover Gram-positive, Gram-negative, and anaerobic bacteria 4
• High-risk patients: Add coverage for MRSA or vancomycin-resistant Enterococcus (VRE) 4
• Multidrug-resistant Gram-negatives: May require polymyxins (colistin), new tetracyclines (glycylglycines), or novel beta-lactam/beta-lactamase inhibitor combinations 4

Duration of Therapy

• Post-surgical mediastinitis: 4-6 weeks of appropriate antibiotic therapy 1
• Adjust based on clinical response and imaging findings 1

Surgical Management

Essential components:

• Elimination of infection source (esophageal repair, removal of infected hardware) 5, 7
• Aggressive drainage of affected mediastinal compartments 5, 7
• Early diagnosis and prompt intervention are critical—mortality approaches 40% despite modern intensive care 7
• Planned CT control after initial therapy to determine need for surgical re-intervention 7
• When in doubt, use more invasive approach (e.g., bilateral thoracotomy) rather than inadequate drainage 7

Fungal Infections in Immunocompromised Patients

For Candida, Aspergillus, and other fungal pathogens in immunocompromised hosts: 4

• Established and novel azoles, amphotericin B, or echinocandins are effective 4
• Important caveat: Detection of Candida in mixed infections does not always necessitate antifungal treatment 4
• Diagnosis requires: Staining and culturing of pericardial fluid or tissue when pericardial involvement is present 3

Critical Diagnostic Considerations

• Imaging is essential: Conventional chest radiography may be misleading; CT or MRI is generally required for diagnosis and evaluation of extent 8
• Blood cultures before antibiotics in suspected infectious causes 3
• Tissue confirmation when malignancy is in differential diagnosis 3
• Pericardiocentesis is absolutely contraindicated if aortic dissection is suspected 3