CO Narcosis in a Patient with Histopathological Features Suggestive of Aspergillus Tracheobronchitis during Treatment for Malignant Lymphoma.

Aspergillus tracheobronchitis (ATB) is a rare but severe infection in immunocompromised patients that is distinct from invasive pulmonary aspergillosis. A 50-year-old man undergoing dexamethasone, methotrexate, ifosfamide, L-asparaginase, and etoposide chemotherapy for NK/T-cell lymphoma developed febrile neutropenia and worsening respiratory failure. Computed tomography revealed airway epithelial detachment and bronchoscopy confirmed pseudomembrane formation. Due to his "Do Not Intubate" status, mechanical ventilation was not initiated, and he died of CO narcosis. Autopsy histopathologically confirmed pseudomembranous ATB. This case underscores the need for early bronchoscopy in high-risk patients with type 2 respiratory failure that cannot be explained by imaging findings alone, highlighting the crucial need for timely intervention to improve outcomes.