Exploring Infection Risk Factors and Multidrug-Resistant Organisms (MDROs) in Burn Intensive Care Units: A Multicenter Case-Control Study.

Background: Despite the widespread incidence of MDRO within burn centers, there is a lack of research investigating infection risks in critically ill burn patients. This study aimed to identify the risk factors associated with the acquisition of MDROs among critically ill burn patients admitted to the Burn ICU (BICU) and to determine the prevalence of MDROs in this population.

Method: This was a multicenter observational case-control study included adult patients (age≥18) admitted to BICU between January, 2015, to December, 2022. Patients were excluded if burn injury affected < 10% of the body surface area (BSA), died within 24 hours of ICU admission, unknown timing of burn injury, and history of MDRO within 1 year prior to admission or antibiotics use 3 months prior to admission. We identified the risk factors and prevalence of MDROs, ICU length of stay (LOS), hospital LOS, 30-day mortality, and in-hospital mortality rates as the study outcomes. An exact matching approach with 1:1 ratio was used to match the groups based on age, gender, and admission year. Stepwise forward selection logistic and linear regression analyses were used when appropriate.

Results: A total of 173 patients were included, and only 168 patients were matched: 84 patients in the case group (MDR) were matched with 84 patients in the control group (non-MDR). Patients who had MDR organisms had lower Glasgow Coma Scale (GCS) baseline (Unadjusted OR: 0.88, 95% CI [0.827, 0.944]), higher baseline Sequential Organ Failure Assessment (SOFA) score (Unadjusted OR: 1.19, 95% CI [1.069, 1.329]), APACHE II score (Unadjusted OR: 1.11, 95% CI [1.054, 1.161]), invasive mechanical ventilation (MV) status at admission (Unadjusted OR: 3.76, 95% CI [1.96, 7.20]), and higher total body surface area (TBSA) affected (Unadjusted OR: 1.04, 95% CI [1.024, 1.058]) compared to the non-MDR group. However, regression analysis showed that those with lower Baseline GCS (OR: 0.904, 95% CI [0.828, 0.987]), higher TBSA affected (OR: 1.023, 95% CI [1.002, 1.045]), and urinary tract infections (UTIs) (OR: 7.198, 95% CI [1.973, 26.259]) were significantly more prone to MDR infections. The most common isolated pathogens in the MDRO group was Acinetobacter baumannii (57%), while the most common infection was pneumonia (52.4%). The MDR group had significantly longer MV duration and ICU LOS (median: 12 vs. 0 days, P=0.0002) and (median: 28 vs. 17 days, P=0.0002), respectively. There was no significant difference between the groups in other outcomes.

Conclusion: Our study showed a significantly increased risk of infections with MDRO in patients with burn who had larger TBSA burns, lower GCS, and higher SOFA and APACHE II scores. Future studies with larger sample size are needed to confirm our results.