A PLEURAL PLAQUE, MULTIFOCAL CONSOLIDATIONS, AND MARKEDLY ELEVATED INFLAMMATORY MARKERS HINT AT THE ATYPICAL: A CASE OF ARDS AND SEPTIC SHOCK SECONDARY TO LEGIONELLA PNEUMOPHILA

Abstract

TYPE: Case Report TOPIC: Chest Infections INTRODUCTION: Legionella pneumophila (LP) is a common cause of community acquired pneumonia (CAP) and particular diagnostics may be predictive of this atypical infection. CASE PRESENTATION: An 83 year old female with no medical history presented with dyspnea, cough, and fevers. Her oxygen saturation on 6 liters nasal cannula was 88%. Notable labs included a WBC 14.60 k/uL, C-reactive protein 41.2 mg/dL, Procalcitonin 42.06 ng/mL. A CT pulmonary angiogram showed multifocal consolidations and a calcified pleural plaque on the right. She was placed on high flow nasal cannula, infectious workup was sent, and she was started on vancomycin, cefepime, and azithromycin. Her arterial blood gas revealed pH 7.37, PaCO2 38, PaO2 58 on 50% FiO2. On day 2, she was intubated and transferred to the ICU for ARDS and septic shock. With a positive urine antigen for Legionella pneumophila serotype 1, she was switched to levofloxacin. She was weaned off pressors and extubated after 4 days. DISCUSSION: There is increasing incidence of severe legionella infection in the United States requiring ICU admission. Identification is unavailable early in the workup often prompting broad empiric coverage. The use of C-reactive protein and procalcitonin have been studied regarding their diagnostic and prognostic value in CAP. Furthermore, the finding of a pleural plaque in our patient informed on an exposure history that raised the suspicion of an atypical process. CONCLUSIONS: With regard to the management of CAP, there is diagnostic value of inflammatory markers paired with unusual radiographic findings to suggest an atypical pneumonia like LP. DISCLOSURE: Nothing to declare. KEYWORD: Legionella pneumophila