Septic shock from descending necrotizing mediastinitis - Combined treatment with IgM-enriched immunoglobulin preparation and direct polymyxin B hemoperfusion: A case report

Background: Descending necrotizing mediastinitis is a common and progressive polymicrobial infection involving the neck and chest with a high death rate (10 to 40%). From a microbiological point of view, descending necrotizing mediastinitis is sustained by Gram-positive bacteria (43-62%), anaerobes (46-78%), and, rarely, Gram-negative bacteria. Data collected during the Antibiotic Resistance-Istituto Superiore di Sanità project confirmed that Italy is positioned among the countries with the highest levels of resistance in most pathogenic species under surveillance. In particular, 32.9% of Klebsiella pneumoniae isolates were resistant to carbapenem, 33.6% of Staphylococcus aureus to methicillin, and 28.7% and 43.9% of Escherichia coli isolates to third-generation cephalosporins and fluoroquinolones, respectively. Case presentation: We describe the case of a 38-year-old white man with septic shock due to descending necrotizing mediastinitis sustained by multidrug-resistant Gram-negative and Gram-positive bacteria treated after surgery with an IgM-enriched immunoglobulin preparation and polymyxin B hemoperfusion therapy. Conclusion: Despite the contrasting data on the use of immunoglobulins and polymyxin B hemoperfusion in septic shock and the lack of literature in cases of acute mediastinitis caused by both Gram-negative and Gram-positive multidrug-resistant bacteria, we obtained an improvement in clinical conditions and the survival of our patient, against all odds.