Early individualized positive end-expiratory pressure guided by electrical impedance tomography in acute respiratory distress syndrome: a randomized controlled clinical trial

Abstract

Background Individualized positive end-expiratory pressure (PEEP) by electrical impedance tomography (EIT) has potential interest in the optimization of ventilation distribution in acute respiratory distress syndrome (ARDS). The aim of the study was to determine whether early individualized titration of PEEP with EIT improved outcomes in patients with ARDS. Methods A total of 117 ARDS patients receiving mechanical ventilation were randomly assigned to EIT group (n = 61, PEEP adjusted based on ventilation distribution) or control group (n = 56, low PEEP/FiO2 table). The primary outcome was 28-day mortality. Secondary and exploratory outcomes were ventilator-free days, length of ICU stay, incidence of pneumothorax and barotrauma, and difference in Sequential Organ Failure Assessment (SOFA) score at day 1 (ΔD1-SOFA) and day 2 (ΔD2-SOFA) compared with baseline. Measurements and main results There was no statistical difference in the value of PEEP between the EIT group and control group, but the combination of PEEP and FiO2 was different between groups. In the control group, a significantly positive correlation was found between the PEEP value and the corresponding FiO2 (r = 0.47, p < 0.00001) since a given matched table was used for PEEP settings. Diverse combinations of PEEP and FiO2 were found in the EIT group (r = 0.05, p = 0.68). There was no significant difference in mortality rate (21% vs. 27%, EIT vs. control, p = 0.63), ICU length of stay (13.0 (7.0, 25.0) vs 10.0 (7.0, 14.8), median (25th–75th percentile); p = 0.17), and ventilator-free days at day 28 (14.0 (2.0, 23.0) vs 19.0 (0.0, 24.0), p = 0.55) between the two groups. The incidence of new barotrauma was zero. Compared with control group, significantly lower ΔD1-SOFA and ΔD2-SOFA were found in the EIT group (p < 0.001) in a post hoc comparison. Moreover, the EIT group exhibited a significant decrease of SOFA at day 2 compared with baseline (paired t-test, difference by − 1 (− 3.5, 0), p = 0.001). However, the control group did show a similar decrease (difference by 1 (− 2, 2), p = 0.131). Conclusion Our study showed a 6% absolute decrease in mortality in the EIT group: a statistically non-significant, but clinically non-negligible result. This result along with the showed improvement in organ function might justify further reserach to validate the beneficial effect of individualized EIT-guided PEEP setting on clinical outcomes of patients with ARDS. Trial registration: ClinicalTrials, NCT02361398. Registered 11 February 2015—prospectively registered, https://clinicaltrials.gov/show/NCT02361398.

Comparison of Global and Regional Compliance-Guided Positive End-Expiratory Pressure Titration on Regional Lung Ventilation in Moderate-to-Severe Pediatric Acute Respiratory Distress Syndrome

“…They also concluded that if the study population doubled and the intergroup mortality remained unchanged, the mortality of the PEEP group titrated according to the regional compliance would be significantly lower. Recently, Hsu et al ( 9 ) and He et al ( 10 ) reported that PEEP titrated by the regional C rs method can reduce mortality when compared with traditional methods in adult patients with ARDS.…”

“…Several recent reviews have summarized the applications of EIT in the treatment of adult ARDS ( 7 , 8 ). Two randomized controlled studies indicated that EIT-guided PEEP titration may reduce ARDS mortality ( 9 , 10 ). In terms of children, Rosemeier et al reported that during lung recruitment and PEEP titration, EIT could help to minimize regional alveolar overdistension and collapse and improve oxygenation ( 11 ).…”

Imaging the acute respiratory distress syndrome: past, present and future

“…Conversely, this study showed that the best PEEP was 5 cmH 2 O in a third of enrolled severe ARDS patients treated with ECMO. Finally, in a large randomized, open label, controlled trial comparing an EIT-based PEEP selection versus a low PEEP-FiO 2 table, the authors concluded in no difference in PEEP levels, oxygenation, and clinical outcome [ 36 ]. Taken together, these results clearly demonstrate that the priority is PEEP individualization in these patients.…”

Effect of Prone Positioning With Individualized Positive End-Expiratory Pressure in Acute Respiratory Distress Syndrome Using Electrical Impedance Tomography

“…Similarly, recruitable alveolar collapse (CL) can be estimated at lower PEEPs against the best pixel compliance. Previous randomized controlled trials (total n > 200) suggested that PEEP titration using OD and CL information resulted in better clinical outcomes ( He et al, 2021 ; Hsu et al, 2021 ). The limitations of the method were discussed in a previous study ( Zhao et al, 2020 ) and considered in the clinical practice.…”

“…EIT generates cross-sectional images of the impedance distribution within the thorax and measures continuously regional lung volume changes at the bedside ( Hinz et al, 2003 ; Kotani et al, 2016 ; Aguirre-Bermeo et al, 2018 ; Holanda et al, 2018 ). EIT is widely used in lung ventilation assessment in hypoxemia patients, including the PEEP titration (Dalla Corte et al, 2020 ; He et al, 2021 ; He et al, 2020 ; Yun et al, 2016 ; Becher et al, 2021 ; Gibot et al, 2021 ; Muders et al, 2021 ; Scaramuzzo et al, 2020b ).…”