Bloodstream infections in adults undergoing extracorporeal membrane oxygenation: Epidemiology and risk factors

Abstract

Detection of nosocomial infections (NIs) occurring during extracorporeal membrane oxygenation (ECMO) is difficult and their related side effects appear to contribute to the high mortality rates (40–50%) of these patients. The most common ones are ventilator-associated pneumonia and bloodstream infections (BSI). Thus we empirically developed a standardized protocol with systematic blood cultures on days 2, 6, 10 and 15. The objectives of this study were to analyze BSI incidence, distribution of microorganisms, risk factors in adult undergoing ECMO support and to evaluate the efficiency of our protocol. We prospectively included all adult patients who underwent veinoarterial (VA-ECMO) or veinovenous extracorporeal membrane oxygenation (VV-ECMO) between May 2014 and March 2016. Anamnestic data and blood culture results using the protocol and additional blood samples were analyzed. Among the 81 patients who underwent ECMO support for more than 48 hours, 10 patients in the VA-ECMO group ( n = 10/56; 17.9%) and 3 patients in the VV-ECMO group ( n = 3/25; 12%) developed 18 BSI, corresponding to a global rate of 22.4 BSI per 1000 ECMO days. Microorganisms associated with these infections were most frequently gram-negative bacilli. Only the duration of ECMO was significantly correlated with BSI occurrence, with a median duration of 6.5 days for “patients without BSI” and of 14 days for “patients with BSI” ( P = 0.0170). The efficiency of the protocol in diagnosing BSI was roughly 5% (5/96) for the VA-ECMO group and around 6% (3/49) for the VV-ECMO group. Probability of developing BSI in adults undergoing ECMO increases with ECMO duration. Systematic blood cultures do not appear to be an effective way of improving BSI detection.