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An amendment to this paper has been published and can be accessed via the original article.

Background: This study hypothesized that patients with extubation failure exhibit a loss of lung aeration and heterogeneity in air distribution, which could be monitored by chest EIT and lung ultrasound. Methods:Patients at risk of extubation failure were included after a successful spontaneous breathing trial. Lung ultrasound (with calculation of lung ultrasound score (LUS)) and chest EIT (with calculation of the Global inhomogeneity index, front-back Center of ventilation (CoV), Regional ventilation delay (RVD) and Surface available for ventilation) were performed before extubation during pressure support ventilation (H0) and two hours after extubation during spontaneous breathing (H2). EIT was then repeated six hours (H6) after extubation. EIT derived indices and LUS were compared between patients successfully extubated and patients with extubation failure. Results: 40 patients were included, of whom 12 (30%) failed extubation. Before extubation, as compared to patients with successful extubation, patients who failed extubation had a higher LUS (19 vs 10, p=0.003) and a smaller Surface available for ventilation (352 vs 406 pixels, p=0.042). After extubation, GI index and LUS were higher in the extubation failure group, whereas Surface available for ventilation was lower. The RVD and the CoV were not different between groups. Conclusion: Before extubation, a loss of lung aeration was observed in patients who developed extubation failure afterwards. After extubation, this loss of lung aeration persisted and was associated with regional lung ventilation heterogeneity. Trial registration: Clinical trials, NCT04180410, Registered 27 November 2019 – prospectively registered, https://clinicaltrials.gov/ct2/show/NCT04180410.

Extubation failure can occur in 10 to 25% of patients who were successfully separated from their ventilator. In which case, patients need to be re-intubated. To reduce the extubation failure rate, we monitor patients during 48h after extubation using Electrical Impedance Tomography (EIT). In total, we recruited 34 patients from which 8 failed their extubation in the ICU ward. Prediction of extubation success or failure using only non-invasive EIT data show a sensitivity of 0.80 and a specificity of 0.73. The prediction for the 8 extubation failures was accurate for most right after the extubation and achieved 100% accuracy for the measurement set preceding the failure.