Outcome predictors of cirrhotic patients with spontaneous bacterial empyema

Spontaneous bacterial empyema (SBE) is a complication of cirrhotic patients in which a pre-existing pleural effusion becomes infected. This retrospective study was designed to investigate the bacteriology and outcome predictors of SBE in cirrhotic patients.

Medical records of cirrhotic patients treated in a tertiary care university hospital from December 2004 to December 2008 were retrospectively reviewed.

Of 3390 cirrhotic patients seen during the study period, 81 cases of SBE were diagnosed. The incidence of SBE was 2.4% (81/3390) in cirrhotic patients and 16% (81/508) in patients with cirrhosis with hydrothorax. There were 46 monomicrobial infections found in 46 SBE patients. Aerobic Gram-negative organisms were the predominant pathogens (n=29, 63%), and Escherichia coli (n=9, 20%) was the most frequently isolated sole pathogen. The mortality rate of SBE was 38% (31/81). Univariate analysis showed that Child-Pugh score, model for end-stage liver disease (MELD)-Na score, concomitant bacteraemia, concomitant spontaneous bacterial peritonitis, initial intensive care unit (ICU) admission and initial antibiotic treatment failure were predictors of poor outcomes. Multivariate regression analysis demonstrated that the independent factors related to a poor outcome were initial ICU admission [odds ratio (OR): 4.318; 95% confidence interval 1CI) 1.09-17.03; P=0.037], MELD-Na score (OR: 1.267; 95% CI 1.08-1.49; P=0.004) and initial antibiotic treatment failure (OR: 13.10; 95% CI 2.60-66.03).

Spontaneous bacterial empyema in cirrhotic patients is a high mortality complication. The independent factors related to poor outcome are high MELD-Na score, initial ICU admission and initial antibiotic treatment failure. High MELD-Na score may be a useful mortality predictor of SBE in cirrhotic patients.