A Retrospective, Multi-centre Study to Evaluate the Effectiveness of Different Antibiotics/Combinations Being Used in Patients with Blood Stream Infection Caused by CRE (Klebsiella Pneumoniae, Escherichia Coli), CRAB & CRPA. (Outcome Study)

INTRODUCTION: Bloodstream infections (BSIs) caused by multidrug-resistant (MDR) Gram-negative pathogens, including carbapenem-resistant Enterobacterales (CRE) such as Klebsiella pneumoniae, Escherichia coli, carbapenem-resistant Acinetobacter baumannii (CRAB), and carbapenem-resistant Pseudomonas aeruginosa (CRPA), are on the rise and are associated with significantly increased mortality and morbidity. Real-world evidence from studies worldwide highlights the growing threat of antimicrobial resistance. This underscores the urgent need for effective treatment strategies to manage critically ill patients with infections caused by these resistant pathogens. In response, various antibiotics and combinations are being explored and used across different healthcare centers to combat the escalating threat posed by MDR Gram-negative bacteria. However, there remains a critical need for further research to identify optimal therapeutic regimens that ensure both clinical and microbiological cures in these challenging cases. OBJECTIVES: PRIMARY OBJECTIVE: BSI Patients with CRO alive at day 14 from initiation of mono/combination antibiotic therapy. SECONDARY OBJECTIVE: Length of ICU stay. Prevalence pattern of carbapenem-resistant Enterobacterales (CRE) such as Klebsiella pneumoniae, Escherichia coli, carbapenem- resistant Acinetobacter baumannii (CRAB), and carbapenem-resistant Pseudomonas aeruginosa (CRPA). Antibiotic sensitivity profile of carbapenem-resistant Enterobacterales (CRE) such as Klebsiella pneumoniae, Escherichia coli, carbapenem-resistant Acinetobacter baumannii (CRAB), and carbapenem-resistant Pseudomonas aeruginosa (CRPA). MATERIALS AND METHODS: STUDY DESIGN: A multicenter, retrospective, non-interventional trial. INCLUSION CRITERIA: Adults aged 18 years or older. Confirmed culture-based diagnosis of bloodstream infection caused by carbapenem-resistant Enterobacterales (CRE), including Klebsiella pneumoniae and Escherichia coli, as well as carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenem- resistant Pseudomonas aeruginosa (CRPA). Receipt of antibiotic mono-therapy or combination therapy for at least 48 hours, as determined by the treating clinician. EXCLUSION CRITERIA: Cultures positive for organisms from any site other than the bloodstream. Any organisms other than CRE (including Klebsiella pneumoniae, Escherichia coli), CRAB, or CRPA isolated within 14 days of the initiation or end of antibiotic therapy. DATA COLLECTION: Data were abstracted from hospital medical records, either electronic (when available) or paper records in cases where electronic records were not accessible. Patients were identified from the hospital's patient file archive. RESULTS: A total of 136 patient records were retrospectively reviewed from October 2021 to October 2023. Of these, 101 patients had complete data and were included in the analysis, while 35 patients were excluded due to incomplete data. The majority of patients were aged between 40 and 60 years. The cohort consisted of 73.3% males and 26.7% females. Additionally, 56.43% of patients required vasopressor support. This analysis identified 11 distinct mono- or combination antibiotic regimens used to treat infections caused by carbapenem-resistant Enterobacterales (CRE), including Klebsiella pneumoniae and Escherichia coli, as well as carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenem-resistant Pseudomonas aeruginosa (CRPA). The most commonly prescribed therapies were: Klebsiella species were the most prevalent carbapenem-resistant gram-negative organisms, accounting for 63.36% of cases, while Pseudomonas species were the least common, representing only 2.97%. CONCLUSIONS: Overall, this study highlights the variety of therapeutic strategies used in managing carbapenem-resistant bloodstream infections. Notably, the Ceftriaxone/Sulbactam/EDTA-based regimen (either mono- or combination therapy) demonstrated superior survival outcomes compared to other antibiotic regimens. Further research, especially randomised control trials, is needed to refine treatment protocols and improve patient survival in patients with CRE (including Klebsiella pneumoniae, Escherichia coli), CRAB, or CRPA-associated BSI.