Role of multidrug-resistant bacteria in weaning from invasive mechanical ventilation

<bold>Background:</bold> Although multidrug-resistant bacteria (MDR) are common in patients undergoing prolonged weaning, there is little data on their impact on weaning and patient outcomes. <bold>Methods:</bold> This is a retrospective analysis of consecutive patients who underwent prolonged weaning at a university weaning centre from January 2018 to December 2020. The influence of MDR colonisation and infection on weaning success (with or without non-invasive ventilation) compared with weaning failure (continued invasive mechanical ventilation, IMV) or death was investigated. Considered pathogen groups were: multidrug-resistant gram-negative bacteria (MDRGN), methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus spp. (VRE). <bold>Results:</bold> 206 patients were studied. 91 (44%) had evidence of MDR bacteria (32 % VRE, 1.5 % MRSA, 16 % MDRGN), 25 patients met the criteria for MDR infection. 70.9 % of the 206 were successfully weaned from IMV, 8.7 % died. The main cause of death was infections (72.2%). Patients with MDR (infection and colonisation) had a higher incidence of weaning failure than those without (48% vs. 34.8% vs. 21.7%). In multivariate analyses, MDR infection (OR 4.9, p=0.004) was an independent risk factor for weaning failure, along with male sex, Charlson Comorbidity Index, pH, and duration of IMV before admission. MDR infection was the only independent risk factor for death (OR 6.66, p=0.007). <bold>Conclusion:</bold> Patients with MDR infection are significantly more likely to die during the weaning process. There is an urgent need to develop non-antibiotic approaches for the prevention and treatment of MDR infections. Research on antibiotic stewardship in prolonged weaning is needed.