Predictors Of And Mortality From Resistant Infections In Icu Patients
BACKGROUND: Resistant infections are a source of healthcare utilization and cost. We hypothesized that the risk factors for resistant Gram-negative rods (rGNR), resistant Gram-positive cocci (rGPC), and fungal infections would be similar in a cohort of ICU-acquired infections.
METHODS: Data were collected on patients requiring intensive care from 1997 to 2017 in a single university surgical-trauma ICU. Patients with ICU-acquired infections were analyzed, conditioned on the presence of rGNR, rGPC, or fungi. Continuous variables were compared using Student's t-test and categorical variables were compared using the chi-square test. Independent predictors of the presence of a resistant pathogen and mortality were determined by logistic regression analysis.
RESULTS: 4319 ICU-acquired infections were identified; 1998 were resistant and 2321 were non-resistant. Any resistant organism infection was significantly associated with female sex, non-trauma diagnosis, APACHE II score, liver disease, steroid use, any prior infection, and a prior resistant infection, but not days of prior antibiotic use (all p ≤ 0.02, C = 0.72, H-L test = 0.001). Controlling for severity of illness and demographics, resistant infections were not associated with mortality compared to non-resistant infections (OR = 1.12, p = 0.17, C = 0.74, H-L test = 0.08).
CONCLUSION: The likelihood of rGNR infection appears to be most closely linked to recent antimicrobial exposure, while rGPC infection appears to be associated with totality of prior antimicrobial exposure. Fungal infections may not be associated with prior exposure. These findings suggest disparate mechanisms of dysbiosis for different classes of resistant pathogens.