A RARE CASE OF METHICILLIN-RISISTANT STAPHYLOCOCCUS AUREUS EMPYEMA NECESSITANS VISUALIZED ON POINT-OF-CARE ULTRASOUND

Abstract

TOPIC: Imaging TYPE: Medical Student/Resident Case Reports INTRODUCTION: Empyema necessitans is a rare complication of bacterial pneumonia that occurs when empyema invades the parietal pleura and extends into the surrounding chest wall; if left unchecked it will eventually drain through the skin. Here we present a case of empyema necessitans in a previously healthy 25 year-old man caused by MRSA pneumonia, visualized with bedside ultrasound. CASE PRESENTATION: This gentleman originally presented to an outside hospital with two months of worsening dyspnea, cough, and pleuretic chest pain. He reported night sweats and fever after a recent upper respiratory infection. He denied having any past medical conditions, however his social history endorses intravenous drug use. Prior to his final presentation he presented to an emergency department twice, being diagnosed with costochondritis, and discharged with oral pain medications. He was then treated with two courses of oral antibiotics from an urgent care. During this time he began to develop a fluctuant erythematous anterior chest wall mass. At this point he presented again to an outside hospital, who then obtained a computed tomography (CT) scan of his chest, revealing a large loculated pleural effusion concerning for empyema that may have been communicating with the mass. He was then transferred to our facility to evaluate this complicated pleural effusion. At our facility a point-of-care ultrasound exam was performed, showing a heterogeneous, echogenic pleural effusion that was freely communicating and flowing across a defect in the intercostal muscles directly into the anterior chest wall mass, highly concerning for empyema necessitans. A small chest tube was placed, with purulent fluid that grew MRSA on culture, confirming the diagnosis. Ultimately the patient required surgical intervention for decortication and pleurectomy along with intravenous vancomycin. DISCUSSION: Rapid identification of empyema necessitans is crucial to facilitate the appropriate treatment, which often involves surgical management, in a timely manor to avoid morbidity and mortality. CONCLUSIONS: POCUS in the hands of a trained clinician provides a rapid, accurate, and cost effective diagnostic approach to those with pneumonia and a chest wall mass, to diagnosis empyema necessitans. REFERENCE #1: Elyashiv D, Alpert EA, Granat N. Empyema Necessitans Diagnosed by Point-of-Care Ultrasound. J Emerg Med. 2020 Dec;59(6):e221-e223. doi: 10.1016/j.jemermed.2020.09.020. Epub 2020 Oct 13. PMID: 33059991. DISCLOSURES: Advisory Committee Member relationship with EchoNous Please note: 11/12/2020 Added 04/30/2021 by Keith Barron, source=Web Response, value=Ownership interest Stock ownership relationship with Butterfly IQ Please note: 04/30/2021 Added 04/30/2021 by Keith Barron, source=Web Response, value=Ownership No relevant relationships by Stephanie Scott, source=Web Response