Antibiotic resistance and mortality in icu patients: a retrospective analysis of first culture growth results in rnt medical college, Udaipur

Background: Intensive care unit (ICU) patients are highly vulnerable to infections due to immunosuppression, invasive procedures, prolonged hospitalization, and widespread antibiotic exposure. Multidrug-resistant (MDR) organisms remain a major cause of hospital-acquired infections, limiting treatment options and increasing mortality. Methods: This retrospective observational study included 60 ICU patients aged ≥18 years with at least one positive microbiological culture. Only the first culture growth per patient was analyzed. Demographic data, clinical diagnoses, isolated organisms, and antibiotic susceptibility patterns were collected. Standard microbiological techniques and CLSI-based antimicrobial susceptibility testing were used. MDR organisms were defined as resistant to ≥1 agent in ≥3 antimicrobial classes. ICU mortality served as the primary outcome. Results: The mean patient age was 50.63 ± 18.82 years, with a female predominance (5:1). Respiratory involvement was most common (73.33%), with ventilator-associated pneumonia constituting 23.33% of diagnoses. Among 38 isolates, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa were the most frequent (13.16% each). Other isolates included Acinetobacter species, Acinetobacter baumannii, Enterococcus species, and several less common pathogens. Antibiotic susceptibility testing revealed widespread resistance. Polymyxin B exhibited the highest activity across multiple Gram-negative organisms, while tigecycline, levofloxacin, and gentamycin showed moderate effectiveness. Carbapenems demonstrated variable sensitivity, and linezolid and vancomycin remained effective primarily against Gram-positive pathogens. Conclusion: MDR organisms are prevalent among ICU infections, with Gram-negative pathogens dominating the microbiological landscape. Significant resistance to multiple antibiotic classes underscores the urgent need for continuous surveillance, early targeted therapy, and strengthened antimicrobial stewardship to reduce ICU morbidity and mortality