Abstract
Background: Electrical impedance tomography (EIT) is able to detect variations in regional lung electrical impedance associated with changes in both air and blood content and potentially capable of assessing regional ventilation-perfusion relationships. However, regional lung perfusion is difficult to determine because the impedance changes synchronous with the heart rate are of very small amplitude. Objectives: The aim of our study was to determine the redistribution of lung perfusion elicited by one-lung ventilation using EIT with a novel region-of-interest analysis. Methods: Ten patients (65 ± 9 years, mean age ± SD) scheduled for elective chest surgery were studied after intubation with a double-lumen endotracheal tube during bilateral and unilateral ventilation of the right and left lungs. EIT data were acquired at a rate of 25 scans/s. Relative impedance changes synchronous with the heart rate were evaluated in the right and left lung regions. Results: During bilateral ventilation, the mean right-to-left lung ratio of the sum of heart rate-related impedance changes was 1.12 ± 0.20, but the ratio significantly changed (0.81 ± 0.16 and 1.48 ± 0.37) during unilateral left- and right-lung ventilation with reduced perfusion of the non-ventilated lung. Increased perfusion most likely occurred in the ventilated lung because the impedance values summed over both regions did not change (0.62 ± 0.23 vs. 0.58 ± 0.22) compared with bilateral ventilation. Conclusions: Our results indicate that redistribution of regional lung perfusion can be assessed by EIT during one-lung ventilation. The performance of EIT in detecting changes in lung perfusion in even smaller lung regions remains to be established.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.