Gut reaction: infectious pericarditis in a patient with metastatic adenocarcinoma of lung

SESSION TITLE: Challenging Chest Infections Cases SESSION TYPE: Rapid Fire Case Reports PRESENTED ON: 10/10/2023 09:40 am - 10:25 am INTRODUCTION: Bacterial pericarditis is a rare condition with a high mortality of 40% despite treatment. It generally occurs due to direct infection secondary to trauma or as a procedural complication. We present a case of acute bacterial pericarditis due to an uncommon cause. CASE PRESENTATION: A 74-year-old female with no significant medical history presented with epigastric pain that radiated to the chest and flu-like symptoms. Her vital signs and initial labs were within normal range. Electrocardiogram showed normal sinus rhythm. Computerized-tomography of the chest revealed right pleural effusion with moderate pericardial effusion. Shortly after initial work-up, the patient developed acute hypoxic respiratory failure and circulatory shock requiring vasopressor support. She was started on broad spectrum antibiotics and colchicine for presumed pericarditis. Echocardiogram showed large pericardial effusion with cardiac tamponade. Patient underwent emergent pericardiocentesis with pericardial window. Pericardial fluid was cultured and returned positive for Escherichia coli and Lactobacillus rhamnosus.Follow-up imaging of the chest showed a new density in the right middle lobe of the lung with extensive lymphadenopathy. Pericardial fluid cytology was reported to be metastatic adenocarcinoma consistent with a lung primary. Metastasis to her abdomen and brain were also seen on subsequent imaging. It was deduced that bacteria from the gastrointestinal tract translocated to the pericardium due to her underlying metastatic disease. Patient continued to improve and was discharged home with outpatient follow up. DISCUSSION: Pericarditis is idiopathic in a majority of cases with infections accounting for a small proportion. Neoplasms are involved in 5% of pericarditis but is usually non infectious. Approximately 10% of pericarditis is viral in origin with bacteria accounting for <1% of cases. Direct inoculation as seen in trauma/procedures, spread from intrathoracic, myocardial or subdiaphragmatic foci, or hematogenous dissemination are the most common causes of bacterial pericarditis. The most common bacteria are Gram-positive organisms such as Streptococcus pneumoniae and Staphylococcus aureus. Infection due to gut translocation and by Gram-negative organisms are very rare. To our knowledge, this is the first case of bacterial pericarditis caused by a co-infection of Escherichia coli and Lactobacillus rhamnosus, both of which are part of the gut microbiome. In our patient, abdominal metastasis likely led to gut translocation and eventual development of bacterial pericarditis. CONCLUSIONS: Bacterial pericarditis is a rare entity. When atypical organisms such as Gram-negative and anaerobes are found in the pericardial fluid, differentials should include malignancy and gut translocation. REFERENCE #1: Chiabrando J, Bonaventura A, Vecchié A, et al. Management of Acute and Recurrent Pericarditis. J Am Coll Cardiol. 2020 Jan, 75 (1) 76–92. https://doi.org/10.1016/j.jacc.2019.11.021 REFERENCE #2: Pankuweit, S., Risti, A. D., Seferovi, P. M., & Maisch, B. (2005). Bacterial Pericarditis. American Journal of Cardiovascular Drugs, 5(2), 103–112. https://doi.org/10.2165/00129784-200505020-00004 REFERENCE #3: Zayas, R., Anguita, M., Torres, F., Gime´nez, D., Bergillos, F., Ruiz, M., Ciudad, M., Gallardo, A., & Valle´s, F. (1995). Incidence of specific etiology and role of methods for specific etiologic diagnosis of primary acute pericarditis. The American Journal of Cardiology, 75(5), 378–382. https://doi.org/10.1016/s0002-9149(99)80558-x DISCLOSURES: No relevant relationships by Ussama Ghumman No relevant relationships by Eunae Ko No relevant relationships by Syed Nazeer Mahmood No relevant relationships by Safwan Muhammad No relevant relationships by Amanda Nguyen No relevant relationships by Vashishtha Patel No relevant relationships by Keertana Seeli