Prevalence, Clinical Severity, and Outcomes of Extensively Drug-Resistant and Pan-Drug-Resistant Gram-Negative Infections in a Tertiary Intensive Care Unit: A Retrospective Observational Study.

BACKGROUND: Extensively drug-resistant (XDR) and pan-drug-resistant (PDR) gram-negative bacteria are increasingly encountered in intensive care units (ICUs) and present a serious therapeutic challenge. However, whether resistance phenotype independently drives clinical outcomes remains unclear. This study investigated the prevalence of XDR and PDR gram-negative bacteria in a tertiary ICU and their associations with clinical course, mortality, and ventilator weaning failure. METHODS: We retrospectively reviewed adult patients (>18 years) admitted to a tertiary general ICU and classified them as XDR, PDR, or non-XDR/PDR based on antimicrobial susceptibility results. We recorded demographic data, comorbidities, GCS scores, organ support requirements, and ICU and hospital lengths of stay. Disease severity was quantified using the APACHE II score. Predictors of mortality and weaning failure were identified by univariate and multivariate logistic regression. RESULTS: XDR and PDR gram-negative infections were identified in 12.53% and 6.04% of patients, respectively. Of 463 patients, those with XDR and PDR infections had longer ICU and hospital stays, higher rates of sedation and vasopressor use, higher APACHE II scores, lower GCS scores, hypoalbuminemia, and higher mortality compared with non-XDR/PDR patients. Despite this, resistance phenotype did not independently predict mortality or weaning failure in multivariate analysis. Mortality was independently associated with higher APACHE II score, lower GCS, vasopressor and sedation requirements, elevated CRP, and low albumin. Weaning failure was independently predicted by shorter ICU stay and elevated CRP. CONCLUSION: XDR and PDR infections were associated with a more severe clinical course; however, in multivariate analysis, mortality was more strongly associated with physiological deterioration than with resistance phenotype itself.