Abstract

Background. The spread of Gram-negative pathogens with acquired antimicrobial resistance mechanisms is one of the major challenges in modern intensive care. In the management of sepsis in cardiac surgery patients, the critical factor is not the infection itself, but rather the rapid evolution of pathogens from the MDR phenotype to XDR and PDR categories.
Aim: to investigate the microbiological spectrum and antibiotic resistance profiles in cardiac surgery patients with Gram-negative sepsis.
Materials and methods. A retrospective analysis of the medical records of 116 adult patients in the Intensive Care Unit of the State Institution “Amosov National Institute of Cardiovascular Surgery of the National Academy of Medical Sciences of Ukraine” was conducted for the period 2020-2025. The inclusion criteria were defined as: age >18 years, presence of sepsis (according to Sepsis-3 definitions), and isolation of Gram-negative bacteria from blood. Interpretation of the obtained minimum inhibitory concentration (MIC) values and categorization of strains were performed according to the clinical breakpoints of the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Antimicrobial resistance was classified according to international CDC criteria.
Results. An analysis of the primary reasons for ICU admission revealed that elective admissions accounted for 33.6% of cases, while emergency admissions constituted 66.4%. The predominant reasons for ICU admission among patients with Gram-negative bloodstream infections were elective cardiac surgery – 39 (33.6%) patients, emergency surgery for acute aortic dissection – 18 (15.5%) patients, surgical treatment of infective endocarditis – 16 (13.9%) patients, and ST-segment elevation acute coronary syndrome – 10 (8.8%) patients. Among Klebsiella pneumoniae isolates, the category of pan-drug-resistant (PDR) pathogens was predominant (70.4% of cases), while in the Pseudomonas aeruginosa population, PDR was recorded in 85.7% of cases.
Conclusions. The high prevalence of multidrug-resistant and pan-drug-resistant strains among Gram-negative flora in the ICU necessitates the implementation of effective treatment approaches. Optimization of antibiotic therapy regimens is a priority task for overcoming resistance and improving the effectiveness of medical care for this patient group