RT Journal Article
SR Electronic
T1 Changes in regional distribution of gas and blood volumes within a single respiratory cycle: Effect of tidal volume, PEEP and respiratory pattern
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP P543
VO 44
IS Suppl 58
A1 Liisa Porra
A1 Mats Wallin
A1 Magnus Hallbäck
A1 Ludovic Broche
A1 Pekka Suortti
A1 Anssi Sovijärvi
A1 Ferenc Petak
A1 Walid Habre
A1 Sam Bayat
YR 2014
UL http://erj.ersjournals.com/content/44/Suppl_58/P543.abstract
AB Rationale: Regional lung function depends on the amount of capillary blood that interfaces with alveolar air, and both parameters dynamically change during the respiratory cycle. Although the spatial distribution of regional blood (Vb) and gas (Vg) within the lung has previously been assessed by different techniques, the dynamic changes of these parameters during the respiratory cycle have not been directly quantified.Methods: We used K-edge subtraction synchrotron CT imaging and a post-gating reconstruction sequence to quantitatively image regional Vg, tissue density and Vb in 6 anaesthetized healthy and mechanically ventilated rabbits. Images were repeatedly collected during ventilation and steady-state inhalation of 70% Xe, or iodine infusion. Data were acquired in 2 different axial chest positions, PEEP, VT and breathing patterns. Regional Vg and Vb were calculated from xenon and iodine distributions, respectively.Results: A video of the dynamic changes in gas and blood volume during the respiratory cycle was obtained. Changes in the Vg and Vb are shown in the Figure.Figure: Relative lung gas and blood volumes during 2 successive respiratory cycles.Conclusions: This study shows for the first time, the relation between regional blood and gas volume during the respiratory cycle. The dynamics of Vg and Vb were affected both by VT and PEEP level.