Electrical impedance tomography during major open upper abdominal surgery: a pilot-study

BMC Anesthesiology

Research Article

Ursula Schmalz¹  Peter Kienbaum¹  Bea Bastin¹  Viktoria Wania¹  Tanja A Treschan¹  Maximilian S Schaefer¹  Martin Beiderlinden² 

[1] Department of Anaesthesiology, Duesseldorf University Hospital, Heinrich-Heine University Duesseldorf, Moorenstraße 5, 40225, Duesseldorf, Germany;Department of Anaesthesiology, Duesseldorf University Hospital, Heinrich-Heine University Duesseldorf, Moorenstraße 5, 40225, Duesseldorf, Germany;Department of Anaesthesiology, Marienhospital Osnabrück, Bischofsstraße 1, 49074, Osnabrück, Germany;

关键词: Electrical impedance tomography;    General anesthesia;    Abdominal surgery;    Atelectasis;    Lung function;   

DOI  :  10.1186/1471-2253-14-51

 received in 2014-02-20, accepted in 2014-07-02,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundElectrical impedance tomography (EIT) of the lungs facilitates visualization of ventilation distribution during mechanical ventilation. Its intraoperative use could provide the basis for individual optimization of ventilator settings, especially in patients at risk for ventilation-perfusion mismatch and impaired gas exchange, such as patients undergoing major open upper abdominal surgery. EIT throughout major open upper abdominal surgery could encounter difficulties in belt positioning and signal quality. Thus, we conducted a pilot-study and tested whether EIT is feasible in patients undergoing major open upper abdominal surgery.MethodsFollowing institutional review board’s approval and written informed consent, we included patients scheduled for major open upper abdominal surgery of at least 3 hours duration. EIT measurements were conducted prior to intubation, at the time of skin incision, then hourly during surgery until shortly prior to extubation and after extubation. Number of successful intraoperative EIT measurements and reasons for failures were documented. From the valid measurements, a functional EIT image of changes in tidal impedance was generated for every time point. Regions of interest were defined as horizontal halves of the picture. Monitoring of ventilation distribution was assessed using the center of ventilation index, and also using the total and dorsal ventilated lung area. All parameter values prior to and post intubation as well as extubation were compared. A p < 0.05 was considered statistically significant.ResultsA total of 120 intraoperative EIT measurements during major abdominal surgery lasting 4-13 hours were planned in 14 patients. The electrode belt was attached between the 2nd and 4th intercostal space. Consecutive valid measurements could be acquired in 13 patients (93%). 111 intraoperative measurements could be retrieved as planned (93%). Main obstacle was the contact of skin electrodes. Despite the high belt position, distribution of tidal volume showed a significant shift of ventilation towards ventral lung regions after intubation. This was reversed after weaning from mechanical ventilation.ConclusionsDespite a high belt position, monitoring of ventilation distribution is feasible in patients undergoing major open upper abdominal surgery lasting from 4 to 13 hours. Therefore, further interventional trials in order to optimize ventilatory management should be initiated.

【 授权许可】

Unknown   
© Schaefer et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.