Necrotising Lung Infections and Respiratory ECMO-Incidence and Outcome A Retrospective Cohort Study in Adult Patients

BackgroundNecrotizing lung infections (NLI) are rare yet severe complications of lower respiratory tract infections with high mortality. Due to their scarcity and varying severity, there are no specific guidelines on managing these entities. Incidence and outcomes of NLI in patients on VV-ECMO remains largely unknown.MethodsThis observational cohort study retrospectively analyzed data from a prospective ECMO registry at University Medical Centre Ljubljana. Consecutive adult VV-ECMO patients hospitalized between 2010 and 2023 were screened. Patients with NLI, defined as computed tomography (CT) documented necrotising pneumonia, lung abscess or necrotizing cavitation were identified and included in the analysis.ResultsOut of 125 VV-ECMO patients with severe respiratory failure due to lung infections, 38 (30.4%) had NLI. Majority of patients (71%) initially presented with viral pneumonia with secondary bacterial superinfection and most had multi-lobar involvement (73.7%). There was considerable overlap of all necrotizing entities. Duration of hospitalization prior to ECMO initiation was the only significant factor determining patient outcome (2 days in survivors vs 8 days in non-survivors, p = 0.04), while duration of mechanical ventilation prior to cannulation had no significant effect on patient outcome. Although not statistically significant, survival rates were considerably higher in patients who primarily presented with community-aquired pneumonia compared to those with hospital-aquired pneumonia (38% vs 14%). Patients with additional complications like empyema or bronchopulmonary fistula had poor outcomes, with only 5% survival. Surgical lobectomy was performed in 5 (13%) patients, all patients died. Nine (24%) patients survived to ICU and hospital discharge and were still alive at 1-year follow-up.ConclusionsIncidence of NLI in VV ECMO patients is higher than reported in non-ECMO population. Surgical interventions were not successful in this cohort. Considering the combination of severe respiratory failure and necrotising complications, overall survival rate of respiratory ECMO patients with NLI is still reasonable.