Clinical characteristics, antimicrobial therapy and outcomes of patients with carbapenem-resistant gram-negative bacterial infections: A retrospective study in an Iranian teaching hospital

Abstract

Objectives: The goal of this study was to investigate the clinical characteristics, antibiotic use patterns and outcomes of patients admitted into the intensive care unit (ICU) with infections caused by carbapenem-resistant Gram-negative bacteria (CR-GNB). Methods: A retrospective study included patients admitted to the three separate ICU departments during the period September 2022 to March 2023 in a university hospital in Iran, from whom CR-GNB were isolated. Clinical characteristics, antibiotic use patterns and outcomes of these patients were determined. The Kaplan-Meier method was used for survival analysis. Results: The mean age of the 63 patients was 67.52 +/- 16.89 years and 45 (71.4 ) were male. Klebsiella pneumoniae (n = 46 isolates) and Acinetobacter baumannii (n = 28 isolates) were the predominant pathogens. Respiratory tract infection (n = 49 cases) and wound infection (n = 12 cases) were the most common infection sources. The 14-day and 30-day mortality rates were 17.5 and 47.6 , respectively. Overall mortality was 71.4 . Median survival times for patients under 60 years old was 71.00 18.51-123.49 and over 60 years old was 34.00 31.14-36.86; pvalue: 0.007. All patients had received antibiotics experimentally before acquiring the infection caused by CR-GNB isolates. After CR-GNB isolation, colistin as a last line was given either as monotherapy or in combination with other antibiotics for a median of 10 days for 55 patients. Conclusion: Colistin was the only choice for the treatment of CR-GNB-related infections. Considering the lack of novel (3-lactam-(3-lactamase inhibitor combinations in Iran and the high prevalence of these organisms, the results highlight the urgent need for the implementation of infection control strategies to reduce the dissemination of these strains.