Meta-Analysis
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Hepatol. Jun 27, 2022; 14(6): 1258-1268
Published online Jun 27, 2022. doi: 10.4254/wjh.v14.i6.1258
Spontaneous bacterial empyema in cirrhosis: A systematic review and meta-analysis
William Reiche, Smit Deliwala, Saurabh Chandan, Babu P Mohan, Banreet Dhindsa, Daryl Ramai, Abhilash Perisetti, Rajani Rangray, Sandeep Mukherjee
William Reiche, Department of Internal Medicine, CHI Creighton University Medical Center, Omaha, NE 68124, United States
Smit Deliwala, Department of Internal Medicine, Michigan State University at Hurley Medical Center, Flint, MI 48503, United States
Saurabh Chandan, Rajani Rangray, Sandeep Mukherjee, Division of Gastroenterology and Hepatology, CHI Creighton University Medical Center, Omaha, NE 68124, United States
Babu P Mohan, Daryl Ramai, Department of Gastroenterology, University of Utah, Salt Lake City, UT 84132, United States
Banreet Dhindsa, Division of Gastroenterology and Hepatology, University of Nebraska Medical Center, Omaha, NE 68198, United States
Abhilash Perisetti, Division of Gastroenterology, Parkview Health, Fort Wayne, IN 46845, United States
Author contributions: Reiche W acquisition of data, drafting the article, final approval; Deliwala S acquisition of data, analysis, interpretation of data, drafting the article; Chandan S conceptualization, study search, critical revision, final approval; Mohan B statistical analysis; Dhindsa B, Ramai D, Perisetti A data collection and study search; Rangray R and Mukherjee S critical revision, final approval
Conflict-of-interest statement: The authors deny any conflict of interest.
PRISMA 2009 Checklist statement: The PRISMA 2009 Checklist statement was utilized and is located in the supplementary material uploaded content.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: William Reiche, DO, Doctor, Department of Internal Medicine, CHI Creighton University Medical Center, 7500 Mercy Road, Omaha, NE 68124, United States. reichewilliam@gmail.com
Received: January 21, 2022
Peer-review started: January 22, 2022
First decision: March 16, 2022
Revised: April 6, 2022
Accepted: May 12, 2022
Article in press: May 12, 2022
Published online: June 27, 2022
Abstract
BACKGROUND

Spontaneous bacterial empyema (SBE) occurs when a hepatic hydrothorax becomes infected and runs a course similar to spontaneous bacterial peritonitis (SBP). It remains underdiagnosed as patients with cirrhosis do not routinely undergo diagnostic thoracentesis. Current understanding is limited by small cohorts, while studies reporting its association with ascites/SBP are conflicting.

AIM

To explore the incidence of SBE, to determine its association with ascites, and to summarize what is known regarding treatment and outcomes for patients with SBE.

METHODS

Major databases were searched until June 2021. Outcomes include the incidence of SBE in pleural effusions, SBP in peritoneal fluid, and SBE in patients without ascites within our cohort of patients with cirrhosis. We performed a meta-analysis using a random-effects model with pooled proportions and 95% confidence intervals (CI). We assessed heterogeneity using I2 and classic fail-safe to determine bias.

RESULTS

Eight studies with 8899 cirrhosis patients were included. The median age ranged between 41.2 to 69.7 years. The majority of the patients were Child-Pugh B and C. Mean MELD score was 18.6 ± 8.09. A total of 1334 patients had pleural effusions and the pooled incidence of SBE was 15.6% (CI 12.6-19; I2 50). Amongst patients diagnosed with SBE, the most common locations included right (202), left (64), and bilateral (8). Amongst our cohort, a total of 2636 patients had ascites with a pooled incidence of SBP of 22.2% (CI 9.9-42.7; I2 97.8). The pooled incidence of SBE in patients with cirrhosis but without concomitant ascites was 9.5% (CI 3.6-22.8; I2 82.5).

CONCLUSION

SBE frequently occurs with concurrent ascites/SBP; our results suggest high incidence rates of SBE even in the absence of ascites. The pleura can be an unrecognized nidus and our findings support the use of diagnostic thoracentesis in patients with decompensated cirrhosis after exclusion of other causes of pleural effusion. Thoracentesis should be considered particularly in patients without ascites and when there is a high suspicion of infection. The need for diagnostic thoracentesis will continue to be important as rates of multi-drug resistant bacterial infections increase and antibiotic susceptibility information is required for adequate treatment.

Keywords: Spontaneous bacterial peritonitis, Spontaneous bacterial peritonitis, Postparacentesis circulatory dysfunction, Refractory ascites, Hepatic hydrothorax

Core Tip: Identification of risk factors for developing spontaneous bacterial empyema and characterization of spontaneous bacterial empyema are lacking. This is a systematic review and meta-analysis describing spontaneous bacterial empyema and the relationship to ascites in patients with cirrhosis. We investigated the incidence of spontaneous bacterial empyema, the incidence of spontaneous bacterial peritonitis, and the incidence of spontaneous bacterial empyema without ascites in a meta-analysis including eight studies.