Epidemiology of bacteriological analyses in adult patients supported by veinoarterial extracorporeal membrane oxygenation

Abstract

Nosocomial infections (NIs) occurrence during veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support and their complications appear to contribute to the high mortality rates (40–60%) of these patients. The most common ones are ventilator-associated pneumonia and bloodstream infections (BSI). In clinical practice, detection of NIs is difficult due to confounding factors caused by the device. The objectives of our study were to analyze BSI and positive tracheal aspirate (TA) culture incidences, distribution of microorganisms and risk factors in adult undergoing veinoarterial ECMO (VA-ECMO). We prospectively and consecutively included all adult patients who underwent VA-ECMO between May 2014 and March 2016 in our intensive care unit. Anamnestic data, blood culture and TA culture were analyzed. Primary endpoint was the occurrence of a BSI or a positive TA culture more than 24 hours after ECMO initiation and within 48 hours after ECMO discontinuation. Among the 56 patients who underwent ECMO support for more than 48 hours, the BSI prevalence was 27.4 cases per 1000 ECMO days and microorganisms associated were most frequently gram-negative bacilli. As for positive TA cultures, microorganisms associated were oropharyngeal germs and gram-negative bacilli. Two risk factors were associated with nosocomial bacteria occurrence in TA cultures: prior antibiotics and duration of mechanical ventilation more than 5 days. We demonstrated a link between “positive TA culture” and “positive blood culture” and we showed a protective effect of using an antibioprophylaxis on “positive TA culture” and “global positive cultures” development ( Table 1 ). Use of an antibioprophylaxis at ECMO implantation is associated with a decrease of global positive cultures development.