Clinical value of electrical impedance tomography (EIT) in the management of patients with acute respiratory failure: a single centre experience

Objective:to describe our clinical experience using Electrical Impedance Tomography (EIT) in the management of mechanical ventilation in patients with acute respiratory failure and to determine to which extent EIT-guided PEEP setting differed from clinically set values.Approach:a retrospective, observational cohort study performed in a hub centre for the treatment of acute respiratory failure and veno-venous Extracorporeal Membrane Oxygenation (ECMO).Main results:between January 2017 and December 2019, EIT was performed 54 times in 41 patients, not feasible only in one case because of signal instability. More than 50% was on veno-venous ECMO support. In 16 cases (30%) EIT was used for monitoring mechanical ventilation i.e. to evaluate recruitability or sigh setting. In 37 cases (70%) EIT was used to set PEEP both with incremental (11 cases in nine patients) and decremental (26 cases, 18 patients) PEEP trial. Clinical PEEP before decremental PEEP trial (PEEPPRE) was 14.1 ± 3.4 cmH2O and clinical PEEP set by clinicians after PEEP trial (PEEPPOST) was 13.6 ± 3.1 (p =ns). EIT analyses demonstrated that more hypoxic patients were higher derecruited when compared to less hypoxic patients that were, on the contrary, more overdistended (p < 0.05). No acute effects of PEEP adjustment based on EIT on respiratory mechanics or regional EIT parameters modification were observed.Significance:variability of EIT findings in our population confirmed the need to provide ventilation settings individually tailored and EIT confirmed to be an optimal useful clinical bedside noninvasive tool to provide real-time monitoring of the PEEP effect and ventilation distribution.