-
Randomized Controlled Trial
Ventilation distribution assessed with electrical impedance tomography and the influence of tidal volume, recruitment and positive end-expiratory pressure in isoflurane-anesthetized dogs.
- Aline M Ambrosio, Tatiana P A Carvalho-Kamakura, Keila K Ida, Barbara Varela, Felipe S R M Andrade, Lara L Facó, and Denise T Fantoni.
- Department of Surgery, Faculty of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil; Laboratory of Medical Investigation 8, Posgraduate Program in Anesthesiology, Medical School, University of São Paulo, São Paulo, Brazil.
- Vet Anaesth Analg. 2017 Mar 1; 44 (2): 254-263.
ObjectiveTo examine the intrapulmonary gas distribution of low and high tidal volumes (VT) and to investigate whether this is altered by an alveolar recruitment maneuver (ARM) and 5 cmH2O positive end-expiratory pressure (PEEP) during anesthesia.Study DesignProspective randomized clinical study.AnimalsFourteen client-owned bitches weighing 26 ± 7 kg undergoing elective ovariohysterectomy.MethodsIsoflurane-anesthetized dogs in dorsal recumbency were ventilated with 0 cmH2O PEEP and pressure-controlled ventilation by adjusting the peak inspiratory pressure (PIP) to achieve a low (7 mL kg-1; n = 7) or a high (12 mL kg-1; n = 7) VT. Ninety minutes after induction (T90), an ARM (PIP 20 cmH2O for 10 seconds, twice with a 10 second interval) was performed followed by the application of 5 cmH2O PEEP for 35 minutes (RM35). The vertical (ventral=0%; dorsal=100%) and horizontal (right=0%; left=100%) center of ventilation (CoV), four regions of interest (ROI) (ventral, central-ventral, central-dorsal, dorsal) identified in electrical impedance tomography images, and cardiopulmonary data were analyzed using two-way repeated measures anova.ResultsThe low VT was centered in more ventral (nondependent) areas compared with high VT at T90 (CoV: 38.8 ± 2.5% versus 44.6 ± 7.2%; p = 0.0325). The ARM and PEEP shifted the CoV towards dorsal (dependent) areas only during high VT (50.5 ± 7.9% versus 41.1 ± 2.8% during low VT, p = 0.0108), which was more distributed to the central-dorsal ROI compared with low VT (p = 0.0046). The horizontal CoV was centrally distributed and cardiovascular variables remained unchanged throughout regardless of the VT, ARM, and PEEP.Conclusions And Clinical RelevanceBoth low and high VT were poorly distributed to dorsal dependent regions, where ventilation was improved following the current ARM and PEEP only during high VT. Studies on the role of high VT on pulmonary complications are required.Copyright © 2017 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.
Notes
Knowledge, pearl, summary or comment to share?You can also include formatting, links, images and footnotes in your notes
- Simple formatting can be added to notes, such as
*italics*
,_underline_
or**bold**
. - Superscript can be denoted by
<sup>text</sup>
and subscript<sub>text</sub>
. - Numbered or bulleted lists can be created using either numbered lines
1. 2. 3.
, hyphens-
or asterisks*
. - Links can be included with:
[my link to pubmed](http://pubmed.com)
- Images can be included with:
![alt text](https://bestmedicaljournal.com/study_graph.jpg "Image Title Text")
- For footnotes use
[^1](This is a footnote.)
inline. - Or use an inline reference
[^1]
to refer to a longer footnote elseweher in the document[^1]: This is a long footnote.
.