Nosocomial bloodstream infection in critically ill patients: is extracorporeal membrane oxygenation a relevant factor?

BACKGROUND

Nosocomial bloodstream infection (BSI) in critically ill patients can cause clinical deterioration, prolong intensive care unit (ICU) stays, and increase mortality risk. Extracorporeal membrane oxygenation support (ECMO) is a known risk factor for BSI, and infections in these patients are assumed to have a worse prognosis.

AIM

To compare risk factors for BSI between ECMO and non-ECMO patients.

METHODS

A three-year prospective observational study was conducted in a 24-bed medical ICU. Consecutive nosocomial BSI episodes were recorded, and BSIs in mechanically ventilated patients were analysed based on ECMO treatment status.

FINDINGS

A total of 98 BSI episodes were included: 30 (30.6%) in ECMO and 68 (69.3%) in non-ECMO patients. The total number of ECMO patients during the study period was 110, with a bacteraemia rate of 27.7% (20.26 episodes per 1000 treatment-days). In non-ECMO patients, the BSI rate was 7.9% (P < 0.001). ECMO patients were younger and had fewer comorbidities. BSI type and aetiology were similar between groups, but severity was higher in ECMO patients. Although multidrug-resistant micro-organisms were more frequent in ECMO patients, the appropriate treatment rate was similar. ICU mortality was 66.6% in ECMO patients and 30.8% in non-ECMO patients (P < 0.001). However, continuous renal replacement therapy (odds ratio (OR): 3.67), Sepsis Organ Failure Assessment score (OR: 1.54), and COVID-19 diagnosis (OR: 1.54) were the only independent risk factors associated with mortality in BSI patients.

CONCLUSION

Although BSI was more frequent and severe in ECMO patients, ECMO support was not independently related to mortality in patients with healthcare-associated BSI.