Epidemiologyand Clinical Characteristics of Bloodstream Infection in PatientsUnder Extracorporeal Membranous Oxygenation

Abstract

Background: Bloodstreaminfection (BSI) is an important complication of extracorporealmembranous oxygenation (ECMO) and a major cause of mortality.This study evaluated the epidemiological and clinicalcharacteristics of BSI that occur during ECMO applicationaccording to microbial etiology.

Methods: Adultpatients who underwent ECMO from January 2009 to December 2016were retrospectively analyzed for BSI episodes at a 2,700-bed,tertiary center. Epidemiological and clinical characteristicsand outcomes of BSI were evaluated and were compared foretiologic groups (gram-positive cocci, gram-negative rods, andfungi groups). Risk factors for 14-day mortality were analyzed.

Results: Atotal of 1,100 patients underwent ECMO during the study period,and 65 BSI episodes occurred in 61 patients. The BSI incidencewas 8.3 episodes/1,000 ECMO days, which significantly decreasedover time ( P =0.03), primarily in gram-positive cocci BSI. Gram-positivecocci, gram-negative rods, and fungi accounted for 38%, 40%, and22% of the 73 blood isolates, respectively. Baselinecharacteristics were comparable between groups. Catheter-relatedinfection (CRI) and pneumonia were the most common sources ofBSI; 52% of gram-positive cocci BSIs and 79% of fungi BSIs werecaused by CRI, and 75% of gram-negative BSIs by pneumonia.Patients with gram-negative rods BSI died more frequently andearlier than those with other BSIs. Independent risk factors for14-day mortality were older age and gram-negative rods BSI.

Conclusions: Thedecreased BSI incidence during ECMO was mainly because of thedecrease of gram-positive cocci BSI. The high early mortality ofgram-negative rods BSI makes prevention and adequate treatment necessary.