Epidemiology and risk factors of infections among patients with extracorporeal membrane oxygenation in a tertiary heart center

Y. Uygun Kızmaz, Ş. Külahçıoğlu, S. Doğan Kaya, M.E. Gürcü, A. Karagöz, M.K. Kırali

Department of Infectious Diseases and Clinical Microbiology, Kosuyolu High Specialization Training and Research Hospital, Istanbul, Turkey. yesimuygun@hotmail.com

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• Cardiology
• Infectious Diseases

OBJECTIVE: Extracorporeal membrane oxygenation (ECMO) is an important treatment strategy for severe acute respiratory and/or cardiac failure. Despite advancements in device technology and intensive care, mortality rates, and complications remain high. Patients undergoing ECMO are at an increased risk of infection due to factors such as immunosuppression, the presence of cannulas, and variable antibiotic pharmacokinetics. Unfortunately, an acquired infection in these patients can lead to increased morbidity, longer hospital stays, and even mortality. The purpose of this study was to examine the prevalence, profiles, and sites of ECMO-related infections, as well as underlying risk factors associated with these infections.

PATIENTS AND METHODS: We retrospectively analyzed clinical data from 73 patients who received veno-arterial (VA) and/or venovenous (VV) ECMO support due to severe but potentially reversible cardiac and/or pulmonary failure lasting ≥24 hours. We involved patients with no suspicion of pre-existing infection before ECMO insertion from January 2015 to February 2023, classifying them into either infected or non-infected based on available evidence. The estimated probability for infection according to ECMO-day was established. Significance was set at p<0.05. The primary interesting outcome is the infection probability.

RESULTS: Mean age was 52.2±14.8 years in all groups, and 55 (75.3%) were male. Median hospital stay was 6 (2-16) days and duration of ICU was 5 (2-10) days in all groups. The duration of ICU stay was significantly higher in the infected group compared to the non-infected group [10 days (5-15) vs. 3 days (2-7)], p<0.001, respectively. 66 patients (90.4%) received VA ECMO and 18 of them (94.7%) were infected. In all groups, the ECMO wean ratio was 28.8%. Death before 48 hours occurred in 28 patients (38.4%). 26% of patients under ECMO support consisted of the infected group and had 68 episodes per 1,000 ECMO days. Of these, the most frequent infection site was lower respiratory tract infection (47.3%). The most common pathogen among these was K. pneumonia. 39.7% of patients received no antibiotics. The probability of infection was 19% for 1.5 (mean-1SD) ECMO days, approximately 41% for 4 ECMO days, and 52% for (mean+1SD) 6.5 ECMO days.

CONCLUSIONS: Nosocomial infections, which are commonly observed during ECMO procedures, are considered a significant concern. The respiratory system is frequently affected by such infections. Even though the use of antibiotics for prophylaxis remains debatable, it is predicted that there will be an inclination towards the regular application of prophylactic measures and the development of standardized protocols based on solid evidence obtained from prospective research studies in the future.

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