Epidemiology and Clinical Characteristics of Bloodstream Infection in Patients Under Extracorporeal Membranous Oxygenation

Background

Bloodstream infection (BSI) is an important complication of extracorporeal membranous oxygenation (ECMO) and a major cause of mortality. This study evaluated the epidemiological and clinical characteristics of BSI that occur during ECMO application according to microbial etiology.

Methods

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

Results

A total of 1,100 patients underwent ECMO during the study period, and 65 BSI episodes occurred in 61 patients. The BSI incidence was 8.3 episodes/1,000 ECMO days, which significantly decreased over time (P = 0.03), primarily in gram-positive cocci BSI. Gram-positive cocci, gram-negative rods, and fungi accounted for 38%, 40%, and 22% of the 73 blood isolates, respectively. Baseline characteristics were comparable between groups. Catheter-related infection (CRI) and pneumonia were the most common sources of BSI; 52% of gram-positive cocci BSIs and 79% of fungi BSIs were caused by CRI, and 75% of gram-negative BSIs by pneumonia. Patients with gram-negative rods BSI died more frequently and earlier than those with other BSIs. Independent risk factors for 14-day mortality were older age and gram-negative rods BSI.

Conclusions

The decreased BSI incidence during ECMO was mainly because of the decrease of gram-positive cocci BSI. The high early mortality of gram-negative rods BSI makes prevention and adequate treatment necessary.