C46-01 Not Your Average Mucus Plug: Plastic Bronchitis in the Intensive Care Unit

Abstract Introduction Plastic bronchitis (PB) is a rare condition characterized by formation of rubbery, tube-like airway casts. We present a case of PB in an adult leading to acute respiratory distress syndrome (ARDS) in the intensive care unit. Case Presentation A 54-year-old man with a history of tobacco use, peptic ulcer disease, COPD, and known PB presented with bloody stools and pleuritic chest pain. He reported a 35-pack-year smoking history and years of productive cough with colorless sputum. Nine years earlier, he was hospitalized for acute hypoxic respiratory failure with a negative infectious workup despite broad-spectrum antibiotics. During that admission, he expectorated a bronchial cast replicating the right airway tree. Bronchoalveolar lavage (BAL) revealed lipid inclusions, confirming PB. The etiology was suspected to be chronic use of topical menthol rub, though occupational welding exposure was also considered. He was successfully treated with prednisone but lost to follow-up. During the current admission, he was evaluated for gastrointestinal bleeding. The night before planned endoscopy, he developed worsening hypoxemia. Chest radiograph showed left greater than right opacities. ICU was consulted for intubation. Immediately prior to intubation he required pre-oxygenation with heated-high flow nasal cannula to 30% FiO2. He ultimately required fiberoptic guided intubation, and subsequent bronchoscopy revealed and cleared a thick mucus plug in the left mainstem bronchus, improving oxygenation and chest imaging. Following successful endoscopic ablation of a jejunal ulcer, he developed ARDS requiring DEXA-ARDS protocol steroids, paralysis, and inhaled epoprostenol. He also received diuresis, inhaled N-acetylcysteine. He was empirically given ceftriaxone and azithromycin, though BAL studies, respiratory cultures, and procalcitonin were negative. Serial bronchoscopies removed thick secretions, each improving aeration and compliance. After several days, he was extubated and transferred out of the ICU. Pulmonology initiated tiotropium for COPD and arranged outpatient pulmonary function testing and chest CT. Discussion PB involves recurrent formation of mucofibrinous bronchial casts causing airway obstruction. While most cases occur after congenital heart surgery, PB can also result from infection, radiation, environmental exposures, or lymphatic disorders. Diagnosis is clinical with histologic confirmation. Treatment includes bronchodilators, corticosteroids, mucolytics, and inhaled fibrinolytics, while serial bronchoscopy remains essential for airway clearance. Lack of standardized therapy and long-term outcome data limits management. Recurrence is common, necessitating multidisciplinary follow-up. Conclusion PB is rare in adults, and there are few reports of its management in adult ICU patients. Further study is needed to clarify etiology and optimize treatment strategies for critically ill patients. This abstract is funded by: None