RARE BACTERIAL EMPYEMA AFTER A BLUNT TRAUMA

Abstract

TOPIC: Disorders of the Pleura TYPE: Medical Student/Resident Case Reports INTRODUCTION: Pleural effusion (PE) is an accumulation of excess fluid in the pleural space. PE is classified as transudative or exudative. Transudative pleural effusion can result from: increased hydrostatic pressure, decreased oncotic forces or increased negative intrapleural pressure. On the other hand, exudative pleural effusion result from increased capillary permeability and impaired lymphatic drainage caused by inflammatory processes. Parapneumonic effusions such as empyema are related to pneumonia in 20-40%. ß hemolytic Lancefield group A streptococcus pyogenes (GAS) is a common cause of upper respiratory tract and cutaneous infections which commonly is related to streptococcal toxic shock syndrome. GAS is an uncommon pathogen with 1.14 per 100,000 habitants associated to bacterial pneumonia, however the prevalence of GAS associated to empyema is only 0.7%. CASE PRESENTATION: Case of 46-year-old man with history of IVDA who arrived to urgency room due to shortness of breath, dry cough and left pleuritic chest pain of 3 weeks of evolution. He had a chest trauma as a pedestrian 2 weeks prior arrival. He denied fever, night sweats, hemoptysis, palpitations, or weight changes. Vitals signs were remarkable for tachycardia, tachypnea and decreased peripheral oxygen saturation. Physical examination was remarkable for bilateral decreased breath sounds and left side dullness to percussion. ABG's with oxygen supplementation revealed hypercapnia 57.3 mmHg with elevated A-a gradient 66.3 mmHg. CBC showed leukocytosis with left shifting. Chemistry panel was remarkable for metabolic alkalosis 31 mmol/L and lactate dehydrogenase was elevated 615 IU/L. Chest X-Ray showed left sided white lung, followed by a chest CT with bilateral pleuro-parenchyma fibrotic changes, bullae formation, centrilobular emphysema, patchy ground glass appearance at both lung fields and decreased right lung volume with ipsilateral displacement of the heart and mediastinal structures with large, multiloculated left pleural effusion with increased density. Left side thoracentesis performed collecting 120ml of purulent fluid, elevated WBC 150,000 with PMN 65% and gram stain positive. Chest tube was placed and drain 1400ml of brown-yellow purulent fluid and pleural culture showed growth of streptococcus pyogenes group A. Patient started on directed IV antibiotic therapy. DISCUSSION: Empyema is an accumulation of excess pus in pleural space. The M protein, the major virulence factor, is a macromolecule incorporated in fimbriae present on the cell membrane projecting on the bacterial cell wall. It is the primary cause of antigenic shift and antigenic drift among GAS. CONCLUSIONS: We expect to contribute awareness and knowledge to the medical field to always include empyema in the working diagnosis of all patients with progressive dyspnea after blunt trauma. REFERENCE #1: Sakai T, Taniyama D, Takahashi S, Nakamura M, Takahashi T. Pleural empyema and streptococcal toxic shock syndrome due to Streptococcus pyogenes in a healthy Spanish traveler in Japan. IDCases. 2017;9:85-88. Published 2017 Jun 27. doi:10.1016/j.idcr.2017.06.006 REFERENCE #2: Shebl E, Paul M. Parapneumonic Pleural Effusions And Empyema Thoracis. [Updated 2020 Aug 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK534297/ REFERENCE #3: Tamayo E, Montes M, Vicente D, Pérez-Trallero E. Streptococcus pyogenes Pneumonia in Adults: Clinical Presentation and Molecular Characterization of Isolates 2006-2015. PLoS One. 2016;11(3):e0152640. Published 2016 Mar 30. doi:10.1371/journal.pone.0152640 DISCLOSURES: No relevant relationships by Maria Betancourt, source=Web Response No relevant relationships by Marlene Farinacci Vilaro, source=Web Response No relevant relationships by Kyomara Hernandez-Moya, source=Web Response No relevant relationships by Arnaldo Nieves-Ortiz, source=Web Response No relevant relationships by Ivanisse Ortiz Velez, source=Web Response No relevant relationships by Neshma Roman-Velez, source=Web Response