Screening for multidrug resistance carriage and appropriate initial antibiotic treatment of intensive care...

To determine whether hospitalisation in an intensive care unit (ICU) with a routine multidrug-resistant organism (MDRO) screening policy increases appropriate initial antibiotic therapy (IAT) for treatment of patients with ICU-acquired bloodstream infections (BSIs).

A subanalysis of the EUROBACT-2 prospective international cohort study, including adult patients with ICU-acquired BSI. Exposure was the admitting ICU's MDRO screening policy, classified as universal on-admission ± weekly screening versus no screening. Primary outcome was appropriate, empiric IAT given within 24 hours of BSI onset, which was concordant with antimicrobial susceptibilities. Associations were evaluated using mixed-effects logistic regression models. Subgroup analyses by BSI source, causative pathogen, local epidemiology and time period were completed.

Overall, 1800 patients with ICU-acquired BSIs from 304 ICUs were included. Patients were significantly more likely to receive appropriate IAT in the first 24 hours of the BSI onset when hospitalised in MDRO screening versus non screening ICUs (51.8% versus 43.1%; p <0.001). Considering patients' demographics, clinical severity, clustering effects and ICU-level factors, the protective effect of MDRO screening policy remained significant (adjusted OR 1.47, 95% CI 1.09-1.99; p 0.012). This association was strongest in patients with intra-abdominal or respiratory BSI sources, monomicrobial Gram-negative BSIs, ICUs with lower antimicrobial resistance prevalence, in the pre-COVID period and in ICUs performing both on-admission and weekly screening.

More appropriate IAT for ICU-acquired BSIs was given when patients were hospitalised in ICUs practicing routine MDRO screening. These results support the role of regular screening in improving empiric antibiotic decision making for ICU-acquired BSIs.