Bloodstream infections in COVID-19 patients undergoing extracorporeal membrane oxygenation in ICU: An observational cohort study
Simone Carelli, Antonio Maria Dell’Anna, Luca Montini, Giulia Bernardi, Mariangela Gozza, Salvatore Lucio Cutuli, Daniele Natalini, Filippo Bongiovanni, Eloisa Sofia Tanzarella, Gabriele Pintaudi, Maria Grazia Bocci, Alessandra Bisanti, Giuseppe Bello, Domenico Luca Grieco, Gennaro De Pascale, Massimo Antonelli
Abstract
BACKGROUND: COVID-19 patients undergoing ECMO are at highly increased risk of nosocomial infections. OBJECTIVES: To study incidence, clinical outcomes and microbiological features of bloodstream infections (BSI) occurring during ECMO in COVID-19 patients. METHODS: Observational prospective cohort study enrolling consecutive COVID-19 patients undergoing veno-venous-ECMO in an Italian ICU from March 2020 to March 2022. RESULTS: In the study population of 68 patients (age 53 [49-60] years, 82% males), 30 (44%) developed bloodstream infections (BSI group) while 38 did not (N-BSI group) with an incidence of 32 events/1000 days of ECMO. In BSI group pre-ECMO respiratory support was shorter (6 [4-9] vs 9 [5-12] days, p = 0.02) and ECMO treatment was longer (18 [10-29] vs 11 [7-18] days, p = 0.03) than in N-BSI group. The overall ECMO and ICU mortality were 50% and 59%, respectively, without any inter-group difference (p = 1.00). A longer ECMO treatment was independently correlated with higher rate of BSI (p = 0.04, OR [95% CI] 1.06 [1.02-1.11]). Sixteen primary and 14 secondary infectious events were documented. Gram-positive pathogens were more common in primary than secondary BSI (88% vs 43%, p = 0.02) and Enterococcus faecalis (56%) was the most frequent one. Conversely, Gram-negative microorganisms were more often isolated in secondary rather than primary BSI (57% vs 13%, p = 0.02), with Acinetobacter baumannii (21%) and Pseudomonas aeruginosa (21%) as most represented species. The administration of Sars-CoV-2 antiviral drug showed independent correlation with a reduced rate of ICU mortality (p = 0.01, OR [95% CI] 0.22 [0.07-0.73]). CONCLUSIONS: Bloodstream infections represented a frequent complication without worsening clinical outcomes in our COVID-19 patients undergoing ECMO. Primary and secondary BSI events showed peculiar microbiological profiles.