Klebsiella pneumoniae Invasive Liver Abscess Syndrome (Klas/Ilas)—Experience of a Single Center and Up-to-Date Review of the Literature

<b>Background</b>: <i>Klebsiella pneumoniae</i> liver abscess (KLAS) is a potentially life-threatening condition with variable outcomes. Identifying risk factors for mortality is crucial for improving patient management. We aimed to analyze factors associated with in-hospital mortality in a cohort of patients with KLAS and review current diagnostic and treatment challenges. <b>Methods</b>: We retrospectively analyzed clinical, laboratory, microbiological, and treatment data from 20 patients admitted with KLAS. Patients were divided into survivor (<i>n</i> = 15) and non-survivor (<i>n</i> = 5) groups. Univariate analyses were performed using appropriate statistical tests to compare groups and identify mortality-related factors. <b>Results</b>: The overall in-hospital mortality rate was 25.0% (5/20). Factors significantly associated with mortality included undergoing laparotomy drainage (60.0% vs. 6.7%, <i>p</i> = 0.018) and developing in-hospital complications (80.0% vs. 6.7%, <i>p</i> = 0.002). Laparoscopic drainage was significantly associated with survival (93.3% vs. 40.0%, <i>p</i> = 0.026). Trends toward increased mortality were observed with diabetes mellitus and higher glucose levels at admission. Despite <i>p</i>-values < 0.05 from prior Fisher's exact test, and the fact that ESBL positivity (OR = 22, 95% CI 0.86-571.32) and septic shock at admission (OR = 16.08, 95% CI 0.75-343.64) showed a very high point estimate for risk of mortality, the association was not statistically significant in our study. <b>Conclusions</b>: Mortality in this KLAS cohort was considerable. The necessity for open drainage and the development of in-hospital complications emerged as significant predictors of death, while other independent risk factor such as diabetes mellitus, high blood glucose levels at admission, septic shock at admission, and ESBL-positive strains indicated a trend towards unfavorable outcomes. These findings underscore the importance of aggressive sepsis management and addressing antimicrobial resistance. Conflicting results regarding the statistical significance of independent risk factors due to a limited sample size highlight the need for larger studies to confirm these findings.