Antimicrobial and Microbiological Characteristics of Critically III Patients with Complicated Intra-Abdominal Infection: Observational Data from Beth Israel Deaconess Medical Center

Purpose: We describe the clinical characteristics, isolated microorganisms and antibiotics used in patients with cIAIs during ICU stay. Methods: A retrospective analysis of data from Beth Israel Deaconess Medical Center was performed. Results: A total of 316 patients with cIAIs were included, 57.0% of them were male and the median age was 63 years. A total of 239 patients did have cultures taken, and 74 patients had a positive microbial result. The main pathogens were Escherichia coli, Staphylococci (coagulase negative), Enterococcus sp. and Bacteroides fragilis. The main antibiotics given were vancomycin, metronidazole, piperacillin tazobactam and ciprofloxacin. Univariable and multivariable Cox regression analyses showed that receiving more antibiotics reduced ICU mortality, but the same results were not obtained in the analysis of hospital mortality. Conclusion: The main Gram-positive microorganisms for empirical antimicrobial therapy were Staphylococci (coagulase negative), Enterococcus sp. and Staphylococcus aureus, and Gram-negative microorganisms were Escherichia coli, Bacteroides fragilis and Klebsiella pneumoniae. The use of more antibiotics reduced ICU mortality, but the same results were not obtained in the analysis of hospital mortality.