English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

Background  It is not well known what is the main mechanism causing lung heterogeneity in healthy lungs under mechanical ventilation. We aimed to investigate the mechanisms causing heterogeneity of regional ventilation and parenchymal densities in healthy lungs under anesthesia and mechanical ventilation.    Methods  In a small animal model, synchrotron imaging was used to measure lung aeration and regional‐specific ventilation ( sV̇ ). Heterogeneity of ventilation was calculated as the coefficient of variation in  sV̇  ( CV   sV̇  ). The coefficient of variation in lung densities ( CV D  ) was calculated for all lung tissue, and within hyperinflated, normally and poorly aerated areas. Three conditions were studied: zero end‐expiratory pressure ( ZEEP ) and  F I O  2  0.21;  ZEEP  and  F I O  2  1.0;  PEEP  12 cmH 2 O and  F I O  2 1.0 (Open Lung‐ PEEP  =  OLP ).    Results  The mean tissue density at  OLP  was lower than  ZEEP ‐1.0 and  ZEEP ‐0.21. There were larger subregions with low  sV̇  and poor aeration at  ZEEP ‐0.21 than at  OLP : 12.9 ± 9.0 vs. 0.6 ± 0.4% in the non‐dependent level, and 17.5 ± 8.2 vs. 0.4 ± 0.1% in the dependent one ( P  = 0.041). The  CV   sV̇   of the total imaged lung at  PEEP  12 cmH 2 O was significantly lower than on  ZEEP , regardless of  F I O  2 , indicating more heterogeneity of ventilation during  ZEEP  (0.23 ± 0.03 vs. 0.54 ± 0.37,  P  = 0.049).  CV D   changed over the different mechanical ventilation settings ( P  = 0.011); predominantly,  CV D   increased during  ZEEP . The spatial distribution of the  CV D   calculated for the poorly aerated density category changed with the mechanical ventilation settings, increasing in the dependent level during  ZEEP .    Conclusion   ZEEP  together with low  F I O  2  promoted heterogeneity of ventilation and lung tissue densities, fostering a greater amount of airway closure and ventilation inhomogeneities in poorly aerated regions.

Zero expiratory pressure and low oxygen concentration promote heterogeneity of regional ventilation and lung densities