Clinical Characteristics, Infection Profiles, and Hospital Outcomes of Intensive Care Unit Patients Undergoing...

Introduction: Ceftolozane/tazobactam is a β-lactam/β-lactamase inhibitor with potent activity against multidrug-resistant Gram-negative pathogens, notably Pseudomonas aeruginosa. Its use is vital in the management of severe infections in ICU patients, especially where resistance limits first-line antibiotic options. This study aimed to describe the clinical characteristics, infection profiles, antimicrobial therapies, and hospital outcomes of ICU patients in Brazil who were treated with ceftolozane/tazobactam. Methods: A multicenter retrospective analysis was conducted on ICU patients treated with ceftolozane/tazobactam across twelve private hospitals in Brazil admitted between July 2018 and February 2023. Data were extracted from electronic medical records, including demographics, comorbidities, infection characteristics, antimicrobial usage, and hospital outcomes. Additionally, microbiological data and treatment details were evaluated. Descriptive statistics were used for analysis. Results: The study included 104 patients, with a median age of 78 years (IQR 61, 87) and 43% of whom were female. Pneumonia (57%) and urinary tract infections (19%) were the primary indications for treatment. Mechanical ventilation was required in 62 patients (60%). Pathogens were isolated in 44 cases, with ESBL-producing Gram-negative bacteria (34%) and carbapenem-resistant strains (18%) being the most common. Empirical therapy was initiated in 57% of cases, with a median treatment duration of 10 days. Concomitant antibiotics were used in 64% of patients. Mechanically ventilated patients exhibited higher mortality (66% vs. 29%) and prolonged ICU stays (57 vs. 20 days) as compared to non-ventilated patients. Conclusions: Ceftolozane/tazobactam demonstrates efficacy and safety in managing multidrug-resistant Gram-negative infections in ICU settings. However, its empirical use, driven by high resistance rates, underscores the importance of microbiology-guided therapy. The observed high mortality and prolonged ICU stay highlight the critical need for optimized infection management strategies and continued antimicrobial stewardship in critically ill populations.