A 64-year-old man with a history of cryptogenic cirrhosis and prior right-sided hepatic hydrothorax presents with a 2-day history of right-sided pleuritic chest pain and subjective fevers. On admission, the patient was afebrile, hemodynamically stable, and saturating 100% on room air. Exam was remarkable for diminished breath sounds on the right; no ascites present. Labs remarkable for Cr 2.29 (baseline 1.2), WBC 5.8. X-ray revealed large right-sided pleural effusion and atelectasis without infiltrate. A diagnostic and therapeutic thoracentesis was performed. Pleural fluid was transudative, glucose 116, cell count 5000, PMN 2500, and culture grew enterococcus faecalis. Patient was started on ceftriaxone, which was switched to ampicillin based on culture. He was also given two doses of IV albumin. On day 5 of antibiotics, repeat thoracentesis yielded fluid with improved cell count and negative gram stain and culture. He was discharged with amoxicillin to complete 14-day course as well as ciprofloxacin for long-term prophylaxis.
Spontaneous bacterial empyema (SBEM) is an underdiagnosed complication of cirrhosis. It is an infection of preexisting hydrothorax in cirrhotics, with a pathogenesis similar to that of spontaneous bacterial peritonitis (SBP). Risk factors for developing SBEM are the presence of SBP, low pleural fluid protein and complement levels, and advanced liver disease. Up to 40% of cases occur in the absence of SBP and even in the absence of ascites. The diagnostic criteria are similar to that of SBP- serum/fluid albumin gradient >1.1, PMN >250 with positive culture, or PMN >500 with negative culture. Diagnosis of SBEM also requires exclusion of a parapneumonic infection. If a cirrhotic patient presents with pleuritic chest pain, fever, encephalopathy, and declining renal function in the setting of a pleural effusion, diagnostic thoracentesis should be performed. It is important to distinguish between SBEM and parapneumonic empyema because the treatment is different. Pleural fluid in SBEM is transudative, pH >7.4, and normal glucose. The infecting organism is E.coli, klebsiella, enterococcus, or streptococcus. The fluid in a parapneumonic empyema is exudative, pH <7.2, glucose <60, and the organism is streptococcus pneumoniae, legionella, or mycoplasma. Treatment for SBEM is IV antibiotics and albumin, and treatment for parapneumonic empyema is antibiotics and drainage with chest tube. Chest tubes are not used in the treatment of SBEM because it leads to complications due to fluid depletion, protein loss, and electrolyte imbalance. The recommendations regarding antibiotic prophylaxis for SBEM are unclear, however it seems reasonable that prophylactic antibiotics may have a role in patients with prior episodes of SBEM since its pathogenesis is similar to that of SBP.
Physicians should consider SBEM in the appropriate clinical setting and perform diagnostic thoracentesis to help guide therapy.
To cite this abstract:Saikumar H, Arevalo TV. Empyema Without Pneumonia?. Abstract published at Hospital Medicine 2016, March 6-9, San Diego, Calif. Abstract 773. Journal of Hospital Medicine. 2016; 11 (suppl 1). https://www.shmabstracts.com/abstract/empyema-without-pneumonia/. Accessed July 24, 2019.