7: Microbiology in Adult Extracorporeal Life Support Patients – A Single Centre UK Study

Background: Infections in extracorporeal life support (ECLS) patients are well described. Multiple factors: invasive lines, prolonged runs of extracorporeal membrane oxygenation (ECMO), increase infection risks. Methods: Microbiology results from day one of ECMO to seven days after decannulation, in all patients on veno-venous (VV) ECMO and veno-arterial (VA) ECMO from January 2018 – April 2024, were recorded. Results: The study included 254 patients: 110 on VV-ECMO (34.5% =female, mean age =46.9yrs, median number of days on ECMO =13); 144 on VA-ECMO (33.3% =female, mean age =48.2yrs, median number of days on ECMO = 6). Positive blood cultures were identified in 42/110 (38.2%) of VV-ECMO patients, and 30/144 (20.8%) of VA-ECMO patients. The most common organisms isolated in both groups were coagulase-negative staphylococci: 25.7% in VV-ECMO and 32.7% in VA-ECMO. Patients with positive blood cultures were 14.9% higher in the VV-ECMO group; p=0.0035; 95% CI (0.0176- 0.2821). Amongst VA ECMO patients, K. pneumoniae was significantly 16.7% higher; p= 0.0087; 95% CI (0.042-0.292). Positive sputum/BAL cultures were identified in 68/110 (61.8%) of VV-ECMO patients, and 46/144 (31.9%) of VA-EMO patients. The most common organism isolated in both groups was P. aeruginosa: 18% in VV-ECMO and 16.7% in VA-ECMO patients. There were 29.9% more positive sputum/BAL cultures in the VV-ECMO group; p