Comparison of clinical characteristics and outcomes of bloodstream infections due to multidrug-resistant Acinetobacter baumannii and other Gram-negative bacteria in ICU patients

Abstract

Background: Multidrug-resistant (MDR) bloodstream infection (BSI) by Gram-negative bacteria (GNB) is an important cause of mortality in the intensive care unit (ICU). The purpose of this study was to compare the clinical characteristics of some GNB BSIs and to analyze their drug resistance, with an emphasis on the analysis of prognostic risk factors related to MDR-Acinetobacter baumannii (A. baumannii) BSI.Methods: A retrospective study was conducted in the ICU of lianyungang hospital in China. Patients with BSIs due to MDR-A. baumannii, MDR-Klebsiella pneumoniae (K. pneumoniae), MDR-Pseudomonas aeruginosa (P. aeruginosa) and MDR-Escherichia coli (E. coli) were included.Results: The overall drug resistance rate to imipenem of A. baumannii and K. pneumoniae was significantly higher than that of P. aeruginosa and E. coli (95.8% and 75.5% vs 44.6% and 9.2% respectively). The mortality rates were 71.9%, 63.3%, 41.5% and 38.1%, respectively. The multivariate analysis of MDR-A. baumannii BSI, APACHE II score, hormone use, development of septic shock were associated with the 30-day mortality, while high albumin level with survival.Conclusion: The treatment of MDR-A. baumannii and MDR-K. pneumoniae infection resulted difficult due to their high drug resistance rate. However, the understanding of the clinical characteristics of different BSIs might be helpful to predict, to some extent, the pathogenic bacteria involved so as to proceed with an early sensitive antibiotic treatment. The high mortality rate due to BSI MDR-A. baumannii might be correlated with APACHE II score, nutritional status, and hormone therapy, while septic shock was a warning sign of poor prognosis.