C46-08 Broadening Recognition of Necrotizing Pseudomonas Pneumonia in COPD Patients

Abstract Necrotizing pneumonia caused by Pseudomonas aeruginosa is a rare but severe infection, typically observed in immunocompromised individuals or those with underlying pulmonary conditions. We present a case of necrotizing Pseudomonas pneumonia in a 64-year-old male with a significant smoking history and reported chronic obstructive pulmonary disease (COPD). The patient presented with hypotension, acute kidney injury, and metabolic encephalopathy in the setting of new pulmonary infiltrate suspicious for community acquired pneumonia (CAP). Initial imaging revealed patchy consolidation with some emphysematous changes throughout in addition to consolidation with a small cavity in the right lower lobe. The patient was managed as CAP without risk factors for pseudomonal coverage, such as immunocompromise, recent antibiotics, or stay in community living facility. The patient experienced clinical deterioration marked by hypoxemic hypercapnic respiratory failure, acute renal failure, hemodynamic instability, and worsening metabolic acidosis requiring mechanical ventilation. Bronchoscopy was done early in his hospital course with bronchoalveolar lavage (BAL) confirmation of pan-sensitive Pseudomonas Aeruginosa. However, he rapidly progressed over days to extensive necrotizing changes with cavitation and worsening destruction of the lung parenchyma bilaterally, seen via CT scan. Repeat BAL at the end of his hospital course showed evolution of his Pseudomonas Aeruginosa to have multidrug resistance. Appropriate empiric antibiotic therapy had been initially started with broadening after clinical deterioration and subsequently tailored to culture sensitivities. Laboratory evaluation showed declining bicarbonate levels and worsening arterial blood gas parameters, indicating persistent hypercapnia with air trapping and systemic inflammatory response. However, the patient’s condition continued to decline, necessitating prolonged intubation, vasopressor support, surgical evaluation for parenchymal debridement without success, and the patient passed. This case underscores several important lessons. First, Pseudomonas pneumonia predominately occurs in patients with chronic lung diseases and has a 6-8-fold increase in incidence in COPD patients. Second, early recognition and aggressive treatment are critical, but even with appropriate antimicrobial therapy, outcomes may remain poor due to the pathogen’s virulence and the potential for rapid lung destruction. Third, worsening acidosis should be monitored closely as it can signal systemic decompensation and correlate with poor prognosis. This case highlights the importance of vigilant clinical monitoring, the potential need for early surgical consultation in non-resolving necrotizing infections, and the necessity of multidisciplinary care in managing complex pulmonary infections. This abstract is funded by: None