Use of reagent strips for the rapid diagnosis of spontaneous bacterial empyema

Goals: To assess the utility of reagent strips for rapid diagnosis of spontaneous bacterial empyema in cirrhotic patients with hepatic hydrothorax. Background: Analysis of ascitic fluid using reagent strips is a useful diagnostic test for spontaneous bacterial peritonitis. Methods: A reagent strip for leukocyte esterase designed for the testing of urine was used to evaluate pleural fluid analysis in 47 nonselected thoracenteses in 28 cirrhotic patients with hepatic hydrothorax. Results: Twelve spontaneous bacterial empyemas were diagnosed. Simultaneous spontaneous bacterial peritonitis was present in 7 of 10 cases in which ascites fluid was analyzed. When a test result of 3 or 4 was considered positive, sensitivity was 83% (10 of 12), specificity was 100% (35 of 35), and positive predictive value was 100%. When result of 2 or more was considered positive, sensitivity was 92% (11 of 12), specificity was 80% (28 of 35), and negative predictive value was 97%. Conclusion: Analysis of pleural fluid with reagent strips is a rapid, easy to use, and inexpensive tool for the diagnosis of spontaneous bacterial empyema in cirrhotic patients. A positive result should be considered an indication for antibiotic therapy.