Invasive ventilation and closed-loop ventilation in critically ill patients

The aim of this thesis was to investigate the association of ventilation strategies, including closed-loop ventilation, with clinical outcomes in critically ill patients.
In the first part of this thesis, we focused on patients with COVID–ARDS.
Using the PRoVAcT–COVID database, we explored whether different PEEP/FiO₂ strategies were associated with better outcomes. In a large multicenter cohort, a high PEEP/low FiO₂ strategy was associated with improved ICU survival. Further analysis showed that this effect was moderated by respiratory subphenotypes— only patients with the low mechanical power phenotype appeared to benefit. We then studied the timing of spontaneous ventilation initiation and found that an early transition to spontaneous breathing was not associated with improved outcomes. Additionally, we investigated the incidence of air leaks and found it to be relatively high but comparable to rates in pre–COVID ARDS.
The second part of this thesis focused on closed–loop ventilation.
A systematic review of 51 randomized controlled trials highlighted that closed–loop ventilation may optimize ventilator settings and reduce workload. In a prospective cross–over study in ABI patients, we demonstrated that automated ventilation significantly increased the proportion of breaths within optimal protective zones and reduced the proportion in critical zones, outperforming conventional ventilation. These findings support the effectiveness of closed–loop ventilation in improving the delivery of lung- and brain-protective ventilation.