Predictors of Mortality in ICU patients with Multidrug-Resistant Bacterial Infections .

Original Article

Abstract

Objective: To identify clinical, microbiological, and treatment-related predictors of mortality among ICU patients with MDR bacterial infections.

Methodology: This longitudinal observational study was conducted in the Department of Medicine, Karachi Teaching Hospital, from December 2025 to May 2026. We enrolled 250 ICU patients with culture-confirmed MDR bacterial infections. We access demographic characteristics, comorbidities, prior antibiotic exposure, mechanical ventilation, septic shock, acute kidney injury (AKI), MDR pathogen, carbapenem resistance, and appropriateness of empirical antimicrobial therapy. The primary outcome was in-hospital mortality. We compared categorical variables using the Chi-square test and used multivariable logistic regression to identify independent predictors of mortality.

Results: Among 250 patients, 105 (42.0%) died, and 145 (58.0%) survived. The most frequently isolated organisms were Acinetobacter baumannii (72, 28.8%), Klebsiella pneumoniae (61, 24.4%), and Pseudomonas aeruginosa (39, 15.6%). Mortality was higher among patients with septic shock, mechanical ventilation, AKI, carbapenem-resistant infection, previous antibiotic exposure, and inappropriate empirical antimicrobial therapy. On multivariable logistic regression, septic shock was the highest independent predictor of mortality. Other independent predictors were inappropriate empirical therapy, mechanical ventilation, carbapenem-resistant infection, AKI, previous antibiotic exposure, and age >60 years.

Conclusion: Mortality among ICU patients with MDR bacterial infections was high. Septic shock, inappropriate empirical antimicrobial therapy, mechanical ventilation, carbapenem resistance, AKI, previous antibiotic exposure, and older age were important independent predictors of mortality.