Title
Breath-by-breath assessment of acute pulmonary edema using electrical impedance tomography, spirometry and volumetric capnography in a sheep (Ovis Aries) model
Language
English
Description (en)
The bedside diagnosis of acute pulmonary edema is challenging. This study evaluated the breath-by-breath information from electrical impedance tomography (EIT), respiratory mechanics and volumetric capnography (VCap) to assess acute pulmonary edema induced by xylazine administration in anesthetized sheep.To determine the ability and efficiency of each monitoring modality in detecting changes in lung function associated with onset of pulmonary edema. Twenty healthy ewes were anesthetized, positioned in sternal (prone) recumbency and instrumented. Synchronized recordings of EIT, spirometry and VCap were performed for 60 s prior to start of injection, during xylazine injection over 60 s (0-60 s) and continuously for 1 min (60-120 s) after the end of injection. After visual assessment of the recorded mean variables, statistical analysis was performed using a mixed effect model for repeated measures with Bonferroni's correction for multiple comparisons, to determine at which breath after start of injection the variable was significantly different from baseline. A significant change over time was defined as an adjusted p< 0.05. All statistics were performed using GraphPad Prism 0.1.0.Electrical impedance tomography showed significant changes from baseline in all but two variables. These changes were observed simultaneously during xylazine injection at 48 s and were consistent with development of edema in dependent lung (decreased end-expiratory lung impedance, ventilation in centro-ventral and ventral lung region) and shift of ventilation into non-dependent lung (decreased non-dependent silent spaces and increased center of ventilation ventral to dorsal and increased ventilation in centro-dorsal and dorsal lung region). All changes in lung mechanics also occurred during injection, including decreased dynamic respiratory system compliance and increased peak expiratory flow, peak inspiratory pressure and airway resistance at 48, 54 and 60 s, respectively. Changes in VCap variables were delayed with all occurring after completion of the injection.In this model of pulmonary edema, EIT detected significant and rapid change in all assessed variables of lung function with changes in regional ventilation indicative of pulmonary edema. Volumetric capnography complemented the EIT findings, while respiratory mechanics were not specific to lung edema. Thus, EIT offers the most comprehensive method for pulmonary edema evaluation, including the assessment of ventilation distribution, thereby enhancing diagnostic capabilities.
Keywords (en)
Gas-Exchange; Ventilation; Xylazine; Lung; Agonists
DOI
10.3389/fvets.2024.1402748
Author of the digital object
Anthea  Raisis  (Murdoch University)
Stephan H.  Böhm  (Rostock University Medical Centre)
Sarah  Blumer  (Murdoch University)
Johannes  Schramel  (University of Veterinary Medicine Vienna)
Giselle  Hosgood  (Murdoch University)
Martina  Mosing  (University of Veterinary Medicine Vienna / Murdoch University)
Muriel  Sacks  (Murdoch University)
Format
application/pdf
Size
912.5 kB
Licence Selected
CC BY 4.0 International
Type of publication
Article
Name of Publication (en)
Frontiers in Veterinary Science
Pages or Volume
13
Volume
11
Publisher
Frontiers Media Sa
Publication Date
2024
Content
Details
Object type
PDFDocument
Format
application/pdf
Created
05.09.2024 09:41:50
This object is in collection
Metadata
University of Veterinary Medicine Vienna (Vetmeduni Vienna) | Veterinärplatz 1 | A-1210 Vienna | Austria | T +43 1 25077-0