Enterobacteriaceae in ventilated PICU-patients: impact of drug resistances and influence on VAP-acquisition

Abstract

Summary MDR gram-negative bacteria are an emerging problem in Germany and worldwide. The family of Enterobacteriaceae in particular is a common cause for various nosocomial infections. One important way of acquiring nosocomial bacteria is endotracheal intubation, during which potentially drug resistant bacteria can be transported into the lower respiratory tract and eventually cause severe infections such as ventilator-associated pneumonia (VAP). Against this background, we conducted a retrospective single-centre study to investigate the epidemiology of Enterobacteriaceae in tracheal aspirate of 123 ventilated PICU (paediatric intensive care unit) patients between 2005 and 2014. The study aimed to describe the frequency, distribution and resistance-status of Enterobacteriaceae in the lower respiratory tract of ventilated PICU patients; to identify risk factors and to analyse the clinical outcome of endotracheal colonization or infection with multidrug resistant Enterobacteriaceae. Furthermore, we identified patients who had a VAP due to Enterobacteriaceae and investigated risk factors and outcome with special attention to VAPs caused by MDR bacteria. A total of 167 isolates of Enterobacteriaceae were detected in the tracheal aspirate of 123 patients. The most frequently isolated species were Enterobacter spp, E.coli and Klebsiella spp with an overall MDR-proportion of 30.5%. Both incidence of Enterobacteriaceae and proportion of MDR organisms have markedly increased over the study period. Analysis by a CRT model revealed, that colonization or infection with E.coli, presence of gastrointestinal comorbidity and antibiotic exposure of more than 6.5 days prior to tracheal aspirate were the most important independent risk factors for isolation of MDR Enterobacteriaceae in the tracheal aspirate. Clinical outcome did not differ between MDR and non-MDR patients. 19 of the patients included in the study acquired a VAP, mostly caused by Enterobacter spp. VAP patients were younger, with a higher proportion of females compared to males. The most important risk factors for VAP were prolonged stay on PICU, mechanical ventilation and antibiotic pre-treatment. 47.4% of the VAPs were MDR, however, the MDR-status of the causative organism did not affect the clinical outcome of the VAP. The number of VAPs is too small to draw a final conclusion about risk factors and impact of MDR Enterobacteriaceae causing VAP on PICU. The trend of emerging MDR gram-negative organisms in the PICU setting should raise increased awareness. Surveillance, adapted screening- and treatment guidelines as well as new antibiotic agents are needed. Furthermore, the possibility of a respiratory tract infection caused by potentially drug resistant Enterobacteriaceae should be kept in mind whenever a child is on mechanical ventilation. The subject of VAP caused by MDR Enterobacteriaceae on PICU is not yet well investigated and more research is needed to assess epidemiology, risk factors and treatment options.; Nosokomiale Infektionen werden haufig durch…