scholarly journals Electrical Impedance Tomography Analysis Between Two Similar Respiratory System Compliance During Decremetal PEEP Titration in ARDS Patients

2021 ◽  
Author(s):  
Po-Lan Su ◽  
Wei-Chieh Lin ◽  
Yen-Fen Ko ◽  
Kuo-Sung Cheng ◽  
Chang-Wen Chen
Keyword(s):  
Electrical Impedance Tomography ◽  
Respiratory System ◽  
Electrical Impedance ◽  
Peep Level ◽  
Stress Index ◽  
Respiratory System Compliance ◽  
Impedance Tomography ◽  
Additional Information ◽  
Alveolar Collapse ◽  
The Difference

Abstract Purpose The positive end-expiratory pressure (PEEP) level with best respiratory system compliance (Crs) is frequently used for PEEP selection in acute respiratory distress syndrome (ARDS) patients. On occasion, two similar best Crs (where the difference between the Crs of two PEEP levels is < 1 ml/cm H2O) may be identified during decremental PEEP titration. Selecting PEEP under such conditions is challenging. The aim of this study was to provide supplementary rationale for PEEP selection by assessing the global and regional ventilation distributions between two PEEP levels in this situation. Methods Eight ARDS cases with similar best Crs at two different PEEP levels were analyzed using examination-specific electrical impedance tomography (EIT) measures and airway stress index (SIaw). Five Crs were measured at PEEP values of 25 cm H2O (PEEP25), 20 cm H2O (PEEP20), 15 cm H2O (PEEPH), 11 cm H2O (PEEPI), and 7 cm H2O (PEEPL). The higher PEEP value of the two PEEPs with similar best Crs was designated as PEEPupper, while the lower designated as PEEPlower. Results PEEPH and PEEPI shared the best Crs in two cases, while similar Crs was found at PEEPI and PEEPL in the remaining six cases. SIaw was higher with PEEPupper as compared to PEEPlower (1.06 ± 0.10 versus 0.99 ± 0.09, p = 0.05). Proportion of lung hyperdistension was significantly higher with PEEPupper than PEEPlower (7.0 ± 5.1% versus 0.3 ± 0.5%, p = 0.0002). In contrast, proportion of recruitable lung collapse was higher with PEEPlower than PEEPupper (18.6 ± 4.4% versus 5.9 ± 3.7%, p < 0.0001). Cyclic alveolar collapse and reopening during tidal breathing was higher at PEEPlower than PEEPupper (34.4 ± 19.3% versus 16.0 ± 9.1%, p = 0.046). The intratidal gas distribution (ITV) index was also significantly higher at PEEPlower than PEEPupper (2.6 ± 1.3 versus 1.8 ± 0.7, p = 0.042). Conclusions PEEPupper is a rational selection in ARDS cases with two similar best Crs. EIT provides additional information for the selection of PEEP in such circumstances.

scholarly journals Derecruitment volume assessment derived from pressure–impedance curves with electrical impedance tomography in experimental acute lung injury

2020 ◽  
Vol 48 (8) ◽  
pp. 030006052094903
Author(s):  
Xiu-Mei Sun ◽  
Guang-Qiang Chen ◽  
Yu-Mei Wang ◽  
Yi-Min Zhou ◽  
Jing-Ran Chen ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Peep Level ◽  
Impedance Tomography ◽  
Whole Process ◽  
Volume Assessment ◽  
The Mean ◽  
The Difference

Objective To investigate the accuracy of derecruitment volume (VDER) assessed by pressure–impedance (P-I) curves derived from electrical impedance tomography (EIT). Methods Six pigs with acute lung injury received decremental positive end-expiratory pressure (PEEP) from 15 to 0 in steps of 5 cmH2O. At the end of each PEEP level, the pressure–volume (P-V) curves were plotted using the low constant flow method and release maneuvers to calculate the VDER between the PEEP of setting levels and 0 cmH2O (VDER-PV). The VDER derived from P-I curves that were recorded simultaneously using EIT was the difference in impedance at the same pressure multiplied by the ratio of tidal volume and corresponding tidal impedance (VDER-PI). The regional P-I curves obtained by EIT were used to estimate VDER in the dependent and nondependent lung. Results The global lung VDER-PV and VDER-PI showed close correlations (r = 0.948, P<0.001); the mean difference was 48 mL with limits of agreement of −133 to 229 mL. Lung derecruitment extended into the whole process of decremental PEEP levels but was unevenly distributed in different lung regions. Conclusions P-I curves derived from EIT can assess VDER and provide a promising method to estimate regional lung derecruitment at the bedside.

Bedside estimation of recruitable alveolar collapse and hyperdistension by electrical impedance tomography

2012 ◽  
pp. 165-170
Author(s):  
Eduardo L. V. Costa ◽  
João Batista Borges ◽  
Alexandre Melo ◽  
Fernando Suarez-Sipmann ◽  
Carlos Toufen ◽  
...  
Keyword(s):  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Impedance Tomography ◽  
Alveolar Collapse

scholarly journals Measurement of Electrical Impedance Tomography-Based Regional Ventilation Delay for Individualized Titration of End-Expiratory Pressure

2021 ◽  
Vol 10 (13) ◽  
pp. 2933
Author(s):  
Thomas Muders ◽  
Benjamin Hentze ◽  
Stefan Kreyer ◽  
Karin Henriette Wodack ◽  
Steffen Leonhardt ◽  
...  
Keyword(s):  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Peep Level ◽  
Positive End Expiratory Pressure ◽  
Regional Ventilation ◽  
Impedance Tomography ◽  
Clinical Applicability ◽  
Tidal Recruitment ◽  
Controlled Mechanical Ventilation ◽  
Clinical Risks

Rationale: Individualized positive end-expiratory pressure (PEEP) titration might be beneficial in preventing tidal recruitment. To detect tidal recruitment by electrical impedance tomography (EIT), the time disparity between the regional ventilation curves (regional ventilation delay inhomogeneity [RVDI]) can be measured during controlled mechanical ventilation when applying a slow inflation of 12 mL/kg of body weight (BW). However, repeated large slow inflations may result in high end-inspiratory pressure (PEI), which might limit the clinical applicability of this method. We hypothesized that PEEP levels that minimize tidal recruitment can also be derived from EIT-based RVDI through the use of reduced slow inflation volumes. Methods: Decremental PEEP trials were performed in 15 lung-injured pigs. The PEEP level that minimized tidal recruitment was estimated from EIT-based RVDI measurement during slow inflations of 12, 9, 7.5, or 6 mL/kg BW. We compared RVDI and PEI values resulting from different slow inflation volumes and estimated individualized PEEP levels. Results: RVDI values from slow inflations of 12 and 9 mL/kg BW showed excellent linear correlation (R2 = 0.87, p < 0.001). Correlations decreased for RVDI values from inflations of 7.5 (R2 = 0.68, p < 0.001) and 6 (R2 = 0.42, p < 0.001) mL/kg BW. Individualized PEEP levels estimated from 12 and 9 mL/kg BW were comparable (bias −0.3 cm H2O ± 1.2 cm H2O). Bias and scatter increased with further reduction in slow inflation volumes (for 7.5 mL/kg BW, bias 0 ± 3.2 cm H2O; for 6 mL/kg BW, bias 1.2 ± 4.0 cm H2O). PEI resulting from 9 mL/kg BW inflations were comparable with PEI during regular tidal volumes. Conclusions: PEEP titration to minimize tidal recruitment can be individualized according to EIT-based measurement of the time disparity of regional ventilation courses during slow inflations with low inflation volumes. This sufficiently decreases PEI and may reduce potential clinical risks.

Determination of optimal positive end-expiratory pressure based on respiratory compliance and electrical impedance tomography: a pilot clinical comparative trial

2019 ◽  
Vol 64 (2) ◽  
pp. 135-145 ◽  
Author(s):  
Jan Karsten ◽  
Nicolas Voigt ◽  
Hans-Joerg Gillmann ◽  
Thomas Stueber
Keyword(s):  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Peep Level ◽  
Pilot Trial ◽  
Comparative Trial ◽  
Positive End Expiratory Pressure ◽  
Impedance Tomography ◽  
Gold Standard Method ◽  
Intensive Care Patients ◽  
Respiratory Compliance

Abstract There is no agreement on gold standard method for positive end-expiratory pressure (PEEP) titration. Electrical impedance tomography (EIT) may aid in finding the optimal PEEP level. In this pilot trial, we investigated potential differences in the suggested optimal PEEP (BestPEEP) as derived by respiratory compliance and EIT-derived parameters. We examined if compliance-derived PEEP differs with regard to the regional ventilation distribution in relation to atelectasis and hyperinflation. Measurements were performed during an incremental/decremental PEEP trial in 15 ventilated intensive care patients suffering from mild-to-moderate impairment of oxygenation due to sepsis, pneumonia, trauma and metabolic and ischemic disorders. Measurement agreement was analyzed using Bland-Altman plots. We observed a diversity of EIT-derived and compliance-based optimal PEEP in the evaluated patients. BestPEEPCompliance did not necessarily correspond to the BestPEEPODCL with the least regional overdistension and collapse. The collapsed area was significantly smaller when the overdistension/collapse index was used for PEEP definition (p=0.022). Our results showed a clinically relevant difference in the suggested optimal PEEP levels when using different parameters for PEEP titration. The compliance-derived PEEP level revealed a higher proportion of residual regional atelectasis as compared to EIT-based PEEP.

Electrical impedance tomography for lung ventilation monitoring of the dog

2017 ◽  
Vol 45 (01) ◽  
pp. 15-21 ◽  
Author(s):  
Korbinian Pieper ◽  
Martin Zoellner ◽  
Andrea Meyer-Lindenberg ◽  
Simon Gloning
Keyword(s):  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Peep Level ◽  
Peak Inspiratory Pressure ◽  
Lung Ventilation ◽  
Mean Value ◽  
Impedance Tomography ◽  
Ventilation Monitoring ◽  
Entire Lung ◽  
Clinical Conditions

SummaryBackground: Electrical impedance tomography (EIT) is a radiation free technique which takes advantage of the different electrical conductivities of different tissues. Its main field of application is lung ventilation monitoring. The aim of this prospective study was to evaluate the feasibility of collecting EIT information on a sample of dogs with different thoracic shapes under clinical conditions by connecting an electrode belt without fur clipping. Material and methods: Fifteen pulmonary healthy dogs were anaesthetized, positioned in sternal recumbency and ventilated in a pressure-controlled mode at three different positive end-expiratory pressure levels (PEEP) of 0, 5 and 10 cmH2O for five breaths each, with a peak inspiratory pressure of 15 cmH2O. The impedance changes were recorded with a commercial EIT device applied around the thorax. Subsequently, the ventilation regi me was repeated and a computed tomography scan (CT) of the same thoracic segment was performed for each PEEP level. The tidal volume (Vt) was recorded. For the collection of EIT data the sum of regional impedance changes was recorded. The impedance value of the entire lung (global) was recorded and the ventilated area was quartered into four regions of interest (ROI). In a CT image with the fewest adjacent organs, lung tissue was selected to obtain the mean value of lung radiodensitiy in Hounsfield-Units (HU) for the entire lung and for the four ROIs. Results: EIT recordings via the electrode belt were possible without clipping. There was a significant correlation for the parameters of aeration as measured by EIT and CT for both the entire ventilated lung and the corresponding ROIs. The increasing PEEP resulted in a proportional increase of the impedance, and there was a negative correlation between EIT and Vt. The better ventilated dorsal ROIs could be identified using both EIT and CT. An intra-assay coefficient of variation showed a good reproducibility for lung ventilation in anaesthetized dogs in the EIT. Discussion: The results show that EIT is a reliable method for evaluating the ventilation of dogs in a clinical setting. The accuracy of EIT might be improved by using a mesh corresponding to the different thoracic shapes of the dogs.

scholarly journals EIT Imaging of Intracranial Hemorrhage in Rabbit Models Is Influenced by the Intactness of Cranium

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Meng Dai ◽  
Xue-Chao Liu ◽  
Hao-Ting Li ◽  
Can-Hua Xu ◽  
Bin Yang ◽  
...  
Keyword(s):  
Electrical Impedance Tomography ◽  
Intracranial Hemorrhage ◽  
Future Study ◽  
Electrical Impedance ◽  
Imaging Method ◽  
Impedance Tomography ◽  
Whole Brain ◽  
Cerebral Parenchyma ◽  
The Difference ◽  
The One

Electrical impedance tomography (EIT) has been shown to be a promising, bedside imaging method to monitor the progression of intracranial hemorrhage (ICH). However, the observed impedance changes within brain related to ICH differed among groups, and we hypothesized that the cranium intactness (open or closed) may be the one of potential reasons leading to the difference. Therefore, the aim of this study was to investigate this effect of open or closed cranium on impedance changes within brain in the rabbit ICH model. In this study, we first established the ICH model in 12 rabbits with the open cranium and in 12 rabbits with the closed cranium. Simultaneously, EIT measurements on the rabbits’ heads were performed to record the impedance changes caused by injecting the autologous nonheparinized blood into cerebral parenchyma. Finally, the regional impedance changes on EIT images and the whole impedance changes were analyzed. It was surprisingly found that when the cranium was open, the impedance of the area where the blood was injected, as well as the whole brain impedance, decreased with the amount of blood being injected; when the cranium was closed, while the impedance of the area where blood was not injected continued to increase, the impedance of the area where blood was injected decreased within 20s of the blood being injected and then remained almost unchanged, and the whole brain impedance had a small fall and then notably increased. The results have validated that the cranium completeness (open or closed) has influences on impedance changes within brain when using EIT to monitor ICH. In future study on application of EIT to monitor ICH, the cranium completeness should be taken into account for establishing an ICH model and analyzing the corresponding EIT results.

Bedside estimation of recruitable alveolar collapse and hyperdistension by electrical impedance tomography

2009 ◽  
Vol 35 (6) ◽  
pp. 1132-1137 ◽  
Author(s):  
Eduardo L. V. Costa ◽  
João Batista Borges ◽  
Alexandre Melo ◽  
Fernando Suarez-Sipmann ◽  
Carlos Toufen ◽  
...  
Keyword(s):  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Impedance Tomography ◽  
Alveolar Collapse

scholarly journals Volume ratio of two immiscible phases measured by electrical impedance tomography

2018 ◽  
Vol 168 ◽  
pp. 07012 ◽  
Author(s):  
Michal Malík ◽  
Jiří Primas ◽  
Michal Kotek ◽  
Václav Kopecký ◽  
Bohuš Kysela ◽  
...  
Keyword(s):  
Electrical Impedance Tomography ◽  
Food Industry ◽  
Electrical Impedance ◽  
Volume Ratio ◽  
The State ◽  
Theoretical Formula ◽  
Mixing Process ◽  
Impedance Tomography ◽  
Additional Information ◽  
Total Separation

The mixing of two immiscible phases is a process commonly seen in many branches of industry. Whether it be desirable (e.g. mixing of ingredients in chemical or food industry) or undesirable (e.g. sediments or contaminants in water purification) process, it has to be taken into consideration and a detailed description would be beneficial to any end product. This paper deals with a method for observing the volume ratio of two immiscible phases from the state of total separation, during the mixing process until the state of a homogenous mixture using industrial Electrical Impedance Tomography (EIT) system ITS p2+. The paper also shows a great agreement between the data obtained through measurement using this method and data derived from a theoretical formula. Also using EIT the authors were able to provide additional information describing the mixing process in real time.

Sign in / Sign up

Export Citation Format

Share Document