Association between multidrug-resistant bacteria and outcomes in intensive care unit patients: a non-interventional study

Abstract

Background: In intensive care units (ICUs), infections by multidrug-resistant (MDR) microorganisms should be monitored to prevent healthcare-associated infections (HAIs).

Methods: From 2018 to 2020, we investigated all medical records of patients admitted to the ICU of a public university hospital. All patients colonized/infected by MDR microorganisms and submitted to active surveillance cultures (ASCs) were included.

Results and discussion: Male patients prevailed, and 9.5% were positive for MDR bacteria. In-hospital deaths were statistically significant (p < 0.05) for older patients, patients with orotracheal tube use during previous and current hospitalization, and patients with high blood pressure, cardiac and pulmonary diseases, and chronic kidney disease. Carbapenem resistant Enterobacteriaceae was the most frequently resistance profile, followed by extended-spectrum beta-lactamase. The diagnosis or evolution of HAIs was statistically significant (p < 0.0001) for patients treated with meropenem and vancomycin, and in-hospital deaths occurred in 29.5% of patients using polypeptides while the use of macrolides reduced the odds for mortality. The BRADEN Scale demonstrated that 50% of the patients were at high risk of dying.

Conclusion: Patients hospitalized in the ICU, colonized or infected by MDR bacteria, using invasive medical devices, and with underlying medical conditions presented increased mortality rates. The prescription of meropenem and vancomycin should be carefully monitored once patients using these antimicrobials already have or develop an HAI.

Keywords: active surveillance cultures; healthcare-associated infection; intensive care unit; invasive devices; multidrug-resistant bacteria.

Figure 1

MDR profile of the microbial community recovered from ASCs in patients admitted to the intensive care unit of a university public hospital from 2018 to 2020. ESBL, Extended-spectrum beta-lactamase producing Enterobacteriaceae; KPC, Klebsiella pneumoniae carbapenemases producing; KPC/POLY, Klebsiella pneumoniae carbapenemases producing/polymyxin resistant strains; MR, Detection of multidrug resistant microorganism; MRSA, Staphylococcus aureus methicillin-resistant; CRE, Carbapenem resistant Enterobacteriaceae; and VRE, Vancomycin-resistant Enterococci. Data are showed as percentage and each color represent a microorganism as indicated in the legend. (A) Informs the total distribution of bacteria recovered from patients (left side) and their respective resistance profile to antimicrobials (right side). The gray bar represents the percentage (0–100) of all the resistance profiles observed. (B) The five main species and genus are highlighted, and the colored bars correspond the respective percentage of their resistance profile.