2293. Revival of Polymyxins: A Single-Center Historical Cohort of Critically Ill Patients in Brazil

Abstract

Background. The epidemiological scenario of multidrug-resistant bacteria has brought polymyxins back to medical prescriptions, as they are last-line therapy against carbapenem-resistant bacteria. There is a lack of knowledge of which is the best way to use this drug, especially in critically ill patients. We aimed to evaluate polymyxin use in an intensive care unit (ICU) in a university hospital and to describe its epidemiological characteristics. Methods. This historical cohort included all consecutive patients who used polymyxins to treat ventilator-associated pneumonia from January 1, 2017 to January 31, 2018, during hospitalization in an ICU from a public university hospital, endemic for carbapenem-resistant bacteria, in Londrina, Brazil. Microbiological processing for diagnosis followed the guidelines from the Clinical and Laboratory Standards Institute (CLSI). Statistical analyses were performed using MedCalc for Windows, version 18.9 (MedCalc Software, Ostend, Belgium) and significance level adopted was 0.05. Results. There were 179 patients; median of age was 57 years (IQR: 40.0 - 70.75). Polymyxin B was the most prescribed polymyxin (97.2%). Most of the patients had comorbidities (72.6%). Age was higher in the group of patients who died (60.0 vs. 36.5 years, P < 0.0001). Comorbidities prevalence was higher in non-survivors (80.7% vs. 38.2%, P < 0.0001). Sequential Organ Failure Assessment (SOFA) score on polymyxin prescribing day was higher in non-survivors (8.0 vs. 7.0, P = 0.0093), as well as Simplified Acute Physiology Score 3 (SAPS 3) score (70.7 vs. 59.35, P = 0.0003). Thirty-day mortality was 43%. Analysis of 14-day survival showed a higher mortality for patients who had sepsis (Log-rank test, P = 0.0284) and septic shock (Log-rank test, P = 0.0065). Acinetobacter baumannii was the most common etiologic agent, in 125 samples (73.9%), with 97.6% of resistance to carbapenem and 5.6% of resistance to polymyxins. Conclusion. Polymyxin B was the most prescribed polymyxin. Age was higher in non-survivors, as well as comorbidities prevalence, SOFA and SAPS 3 scores. Patients with sepsis and septic shock showed a 14-day higher mortality. Acinetobacter baumannii was the most isolated agent. Carbapenem resistance was high.