Microbiological profiles and clinical outcomes of critically ill surgical patients with lower gastrointestinal perforation in Japan: a single-center retrospective observational study

Abstract

Background: Lower gastrointestinal perforation (LGP) is a surgical emergency disease that can result in secondary bacterial peritonitis. Microbiological studies on LGP are rare. The present study aimed to ascertain the microbiological profile of LGP in patients admitted to the intensive care unit (ICU) at our institute after surgery. In addition, we investigated whether initial empirical therapy with vancomycin was associated with in-hospital mortality, duration of ICU stay, and duration of ventilator support.

Methods: This single-center, retrospective, observational study was conducted at Kobe City Medical Center General Hospital, Japan. The study population included all patients diagnosed with LGP who were admitted to the ICU after emergency surgery between 2017 and 2023. The primary outcome assessed was the microbiological profile of microorganisms isolated from ascites fluid and blood of the participants. The secondary end-points were in-hospital mortality, duration of ICU stay, and duration of ventilator support. We performed univariate and multivariate regression analyses to evaluate the end-points.

Results: During the study period, 89 patients were included in the analysis. The most commonly identified pathogen from the ascites cultures was Escherichia coli (65.2%), followed by Enterococcus spp. (51.7%). E. faecium was identified in 16 (18.0%) ascites samples. The microbiological profile of critically ill patients with LGP admitted to the ICU after surgery was similar to that of previous studies on intra-abdominal infection (IAI). Therefore, the initial empirical therapy in the IAI guidelines is more appropriate for LGP. Multivariate regression analysis suggested that the combination of initial empirical therapy with vancomycin was not associated with in-hospital mortality (odds ratio [OR] = 0.96, 95% confidence interval [CI] 0.23-3.00, p = 0.955), duration of ICU stay (coefficient=-0.92, 95% CI -3.04-1.21, p = 0.393), or duration of ventilator-support (coefficient=-9.03, 95%CI -49.69-31.63, p = 0.659).

Conclusion: The microbiological profile of critically ill patients with LGP admitted to the ICU after surgery was similar to that of previous studies on IAI. However, the frequency of E. faecium in the present study was higher than that in previous studies. Initial empirical therapy with drugs such as meropenem in combination with vancomycin for E. faecium was not associated with in-hospital mortality, duration of ICU stay, and duration of ventilator support, after adjusting for confounding factors.

Keywords: Enterococcus faecium; Intra-abdominal infection; Lower gastrointestinal tract; Microbiology; Vancomycin.