%0 Journal Article %A Luca Fardin %A Ludovic Broche %A Goran Lovric %A Alberto Mittone %A Anders Larsson %A Alberto Bravin %A Sam Bayat %T Within-breath dynamics of atelectrauma during mechanical ventilation studied by in vivo 4D microscopy in injured rabbit lung %D 2020 %R 10.1183/13993003.congress-2020.1933 %J European Respiratory Journal %P 1933 %V 56 %N suppl 64 %X Introduction: Atelectrauma is a mechanism of Ventilator-Induced Lung Injury (VILI) in ARDS patients. High PEEP is applied to prevent atelectrauma but has not conclusively improved survival. It is urgent to understand whether the contribution of atelectrauma to VILI is overestimated or whether PEEP does not prevent its occurrence. Here, we investigate the within-breath pressure-time dependency of atelectrauma under protective ventilation in a rabbit model of VILI.Methods: Lung injury was induced in 5 anesthetized, mechanically ventilated New Zealand White rabbits by whole lung lavage followed by injurious ventilation. Synchrotron radiation 4D microscopy was acquired during protective ventilation (PEEP=5cmH2O) and volumetric images were reconstructed at different phases of the respiratory cycle. Aerated and closed regions were determined at each time point and cross-correlated to compute a map of opening/closing units.Results: Cyclic recruitment and derecruitment of lung units were dynamically mapped and quantified as a function of time and pressure along a whole breath (Figure). Derecruitment was detected at the beginning of expiration at pressures above 10cmH2O.Conclusions: We determined a method allowing to study the within-breath dynamics of atelectrauma during mechanical ventilation. In our VILI model moderate to high PEEP levels may be insufficient to prevent cyclic derecruitment.FootnotesCite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 1933.This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only). %U