Epidemiology, Associated Factors, and Outcomes of Intensive Care Unit–Acquired Infections Caused by Multidrug-Resistant Organism in Critically Ill Patients

Abstract

Abstract Background Nosocomial infections are a major health problem in the intensive care unit (ICU). Limited data exist on the epidemiology of ICU-acquired multidrug-resistant (MDR) microorganism infection. The study aimed to define the clinical characteristics, risk factors, and outcomes associated with the occurrence of an ICU-acquired MDR infection. Methods This is a retrospective, observational, single-center, case-control study, including all patients admitted to the unit between January 2015 and December 2019. Results During the study period, 3507 patients were admitted in the ICU. The overall incidence of ICU nosocomial infection was 9.6%, whereas the incidence of MDR infection was 0.9%, remaining stable throughout the study period. Based on multivariate analysis, only the presence of neutropenia on admission, days of mechanical ventilation, days with a urinary catheter, and ICU length of stay were identified as clinical factors independently associated with MDR infections. The occurrence of these infections was associated with increased length of stay and need for invasive devices, although there were no differences in associated mortality between groups. There was a 46% rate of pathogen-directed antibiotic treatment in cases of MDR infection, although when empirical treatment is used, MDR patients were less likely to receive initial appropriate antimicrobial therapy (25% vs 7%; P < 0.001). Conclusions Multidrug-resistant infections presented a nonnegligible incidence and are associated with the existence of immunosuppression before admission, as well as the need for mechanical ventilation, urinary catheter, and prolonged ICU stay. They represent an increase in patient morbidity, although they are not related to an increase in mortality.