SPONTANEOUS BACTERIAL EMPYEMA: HOW IS IT ACTUALLY DEFINED?

Abstract

SESSION TITLE: Monday Fellow Case Report Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: 10/21/2019 02:30 PM - 03:15 PM INTRODUCTION: Hepatic hydrothorax refers to a pleural effusion in a cirrhotic without another identifiable cause. When this pleural fluid becomes infected, it is called a spontaneous bacterial empyema (SBE). SBE needs to be distinguished from an effusion secondary to a primary lung infection because chest tube drainage is avoided in SBE. We present a case of a cirrhotic patient with an infected pleural space where the diagnosis is not clear based on existing diagnostic criteria for SBE. CASE PRESENTATION: A 64 year old male with alcoholic cirrhosis presented to the Emergency Department for shortness of breath. He had a history of refractory ascites requiring paracentesis every two weeks and a small, right-sided pleural effusion that had been present for two years. Upon presentation, he was tachycardic and hypoxic requiring three liters of oxygen. Initial workup was significant for a white blood cell (WBC) count of 14,000/uL, chest x-ray showed a moderate right-sided pleural effusion, thoracic ultrasound showed a loculated pleural space, and abdominal ultrasound revealed no ascites. A thoracentesis was performed with serosanguinous fluid appearance, WBC of 6,000/uL with 98% neutrophils, pH of 6.50, and a glucose of 172 mg/dL. A chest tube was placed soon after admission. After four days of drainage and intravenous antibiotics, the patient was weaned off supplemental oxygen and his leukocytosis resolved. The chest tube was removed, and he was discharged to complete six weeks of antibiotics. DISCUSSION: Chest tube drainage has been associated with increased incidence of protein loss, kidney injury, and infection in cirrhotic patients [1], and most guidelines recommend against tube drainage for SBE [1, 2, 3]. To our knowledge, there is no consensus definition of SBE (Table 1), and none incorporate the presence of loculations on chest imaging. This patient met some definitions of SBE while not meeting others (Table 1). Because of the low pleural fluid pH and complex appearing pleural space, we proceeded with chest tube drainage despite recommendations to avoid catheter placement in SBE because of concern for inadequate source control with antibiotics alone. The patient’s clinical improvement after chest tube drainage confirmed our suspicion that he likely had a parapneumonic effusion instead of SBE. Integrating pleural loculations and standardizing the definition for SBE may help stratify patients that require chest tube drainage from those that will improve with antibiotics alone. CONCLUSIONS: The diagnostic criteria for SBE is not clear. The lack of a consensus definition can lead to treatment uncertainty and inappropriate delays in chest drainage. Standardizing the diagnostic criteria will allow for more judicious use of chest tube drainage in cirrhotic patients that are at increased risk of catheter related complications. Reference #1: 1. Xiol X, Casais L. Spontaneous Bacterial Empyema in Cirrhotic Patients: Analysis of Eleven Cases. Hepatology. 1990 Mar; 11(3): 365-7 Reference #2: 2. Tu CY, Chen CH. Spontaneous Bacterial Empyema. Curr Opin Pulm Med. 2012 Jul; 18(4): 355-8 Reference #3: 3. Cardenas A, Kelleher B, Chopra S. Hepatic Hydrothorax. UptoDate. Retrieved January 25, 2019 from https://www.uptodate.com/contents/hepatic-hydrothorax DISCLOSURES: No relevant relationships by Kevin Ho, source=Web Response No relevant relationships by Jennifer McCallister, source=Web Response