Evaluation of risk factors associated with mortality in patients with ventilator-associated pneumonia caused by Pseudomonas aeruginosa with difficult-to-treat resistance

ABSTRACT

Introduction: Evaluation of prognostic factors in patients with ventilator- associated pneumonia (VAP) due to P. aeruginosa. The effectiveness of novel antipseudomonal antibiotics was reviewed. Method(s) Retrospective, single-center cohort analysis between April 2018 and June 2022. Data were obtained from the ENVIN-HELICS and electronic medical records. Demographic variables, underlying diseases and diagnosis to admission were registered. We considered each treatment appropriate according to Tamma PD et al. [1] criteria. We registered ventilator-associated tracheobronchitis (VAT) and pneumonia (VAP) episodes together with the recurrency of the infection. Result(s) From 61 patients included, 77% were admitted for ARDS due to COVID-19. The mean APACHE-II was 14.3 +/- 6.6. 7 patients required ECMO and 4 required RRT. The median length of stay in the ICU was 52 (ICR 36-84) days. 91 respiratory infections were recorded 60 VAP and 31 VAT. On the first episode, carbapenem-resistance to meropenem was 40%;rising up to 58% on the second one. 6 patients developed a third episode (VAT) with a 100% of carbapenem- resistance. 13 (14%) respiratory infections showed resistance to the novel beta-lactamase inhibitor cephalosporins (8 to ceftalozanetazobactam and 5 to ceftazidime-avibactam). No resistance to cefiderocol was detected. During ICU stay, 21 patients (34%) developed secondary bacteremia from other foci and 7 (11%) invasive mycoses. Overall mortality was 49.2%. On the univariate analysis we found statistical significant relationships between mortality and COVID-19 admission, SOFA >= 7 points on the first VAP or the development of secondary bacteremia (Table 1). Conclusion(s) COVID-19 admission, SOFA >= 7 points on the first VAP or other secondary bacteremia were associated with mortality. The 14.3% of respiratory infections were resistant to the new beta-lactamase inhibitor cephalosporins. No resistance to cefiderocol was detected.