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Jiang H, Han Y, Zheng X, Fang Q. Roles of electrical impedance tomography in lung transplantation. Front Physiol 2022; 13:986422. [PMID: 36407002 PMCID: PMC9669435 DOI: 10.3389/fphys.2022.986422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 10/25/2022] [Indexed: 11/06/2022] Open
Abstract
Lung transplantation is the preferred treatment method for patients with end-stage pulmonary disease. However, several factors hinder the progress of lung transplantation, including donor shortages, candidate selection, and various postoperative complications. Electrical impedance tomography (EIT) is a functional imaging tool that can be used to evaluate pulmonary ventilation and perfusion at the bedside. Among patients after lung transplantation, monitoring the graft’s pulmonary function is one of the most concerning issues. The feasible application of EIT in lung transplantation has been reported over the past few years, and this technique has gained increasing interest from multidisciplinary researchers. Nevertheless, physicians still lack knowledge concerning the potential applications of EIT in lung transplantation. We present an updated review of EIT in lung transplantation donors and recipients over the past few years, and discuss the potential use of ventilation- and perfusion-monitoring-based EIT in lung transplantation.
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Affiliation(s)
| | | | - Xia Zheng
- *Correspondence: Xia Zheng, ; Qiang Fang,
| | - Qiang Fang
- *Correspondence: Xia Zheng, ; Qiang Fang,
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Heines SJH, de Jongh SAM, Strauch U, van der Horst ICC, van de Poll MCG, Bergmans DCJJ. The global inhomogeneity index assessed by electrical impedance tomography overestimates PEEP requirement in patients with ARDS: an observational study. BMC Anesthesiol 2022; 22:258. [PMID: 35971060 PMCID: PMC9377133 DOI: 10.1186/s12871-022-01801-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 08/08/2022] [Indexed: 11/24/2022] Open
Abstract
Background Electrical impedance tomography (EIT) visualises alveolar overdistension and alveolar collapse and enables optimisation of ventilator settings by using the best balance between alveolar overdistension and collapse (ODCL). Besides, the global inhomogeneity index (GI), measured by EIT, may also be of added value in determining PEEP. Optimal PEEP is often determined based on the best dynamic compliance without EIT at the bedside. This study aimed to assess the effect of a PEEP trial on ODCL, GI and dynamic compliance in patients with and without ARDS. Secondly, PEEP levels from “optimal PEEP” approaches by ODCL, GI and dynamic compliance are compared. Methods In 2015–2016, we included patients with ARDS using postoperative cardiothoracic surgery patients as a reference group. A PEEP trial was performed with four consecutive incremental followed by four decremental PEEP steps of 2 cmH2O. Primary outcomes at each step were GI, ODCL and best dynamic compliance. In addition, the agreement between ODCL, GI, and dynamic compliance was determined for the individual patient. Results Twenty-eight ARDS and 17 postoperative cardiothoracic surgery patients were included. The mean optimal PEEP, according to best compliance, was 10.3 (±2.9) cmH2O in ARDS compared to 9.8 (±2.5) cmH2O in cardiothoracic surgery patients. Optimal PEEP according to ODCL was 10.9 (±2.5) in ARDS and 9.6 (±1.6) in cardiothoracic surgery patients. Optimal PEEP according to GI was 17.1 (±3.9) in ARDS compared to 14.2 (±3.4) in cardiothoracic surgery patients. Conclusions Currently, no golden standard to titrate PEEP is available. We showed that when using the GI, PEEP requirements are higher compared to ODCL and best dynamic compliance during a PEEP trial in patients with and without ARDS. Supplementary Information The online version contains supplementary material available at 10.1186/s12871-022-01801-7.
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Affiliation(s)
- Serge J H Heines
- Department of Intensive Care Medicine, Maastricht University Medical Centre+, P. Debyelaan 25, P.O. Box 5800, 6202, AZ, Maastricht, The Netherlands.
| | - Sebastiaan A M de Jongh
- Department of Intensive Care Medicine, Maastricht University Medical Centre+, P. Debyelaan 25, P.O. Box 5800, 6202, AZ, Maastricht, The Netherlands
| | - Ulrich Strauch
- Department of Intensive Care Medicine, Maastricht University Medical Centre+, P. Debyelaan 25, P.O. Box 5800, 6202, AZ, Maastricht, The Netherlands
| | - Iwan C C van der Horst
- Department of Intensive Care Medicine, Maastricht University Medical Centre+, P. Debyelaan 25, P.O. Box 5800, 6202, AZ, Maastricht, The Netherlands.,Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Marcel C G van de Poll
- Department of Intensive Care Medicine, Maastricht University Medical Centre+, P. Debyelaan 25, P.O. Box 5800, 6202, AZ, Maastricht, The Netherlands.,Department of Surgery, Maastricht University Medical Centre+, P. Debyelaan 25, 6229HX, Maastricht, the Netherlands.,School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, the Netherlands
| | - Dennis C J J Bergmans
- Department of Intensive Care Medicine, Maastricht University Medical Centre+, P. Debyelaan 25, P.O. Box 5800, 6202, AZ, Maastricht, The Netherlands.,School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, the Netherlands
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Santos TBR, Nakanishi RM, de Camargo EDLB, Amato MBP, Kaipio JP, Lima RG, Mueller JL. Improved resolution of D-bar images of ventilation using a Schur complement property and an anatomical atlas. Med Phys 2022; 49:4653-4670. [PMID: 35411573 PMCID: PMC9544658 DOI: 10.1002/mp.15669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 03/31/2022] [Accepted: 03/31/2022] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Electrical impedance tomography (EIT) is a nonionizing imaging technique for real-time imaging of ventilation of patients with respiratory distress. Cross-sectional dynamic images are formed by reconstructing the conductivity distribution from measured voltage data arising from applied alternating currents on electrodes placed circumferentially around the chest. Since the conductivity of lung tissue depends on air content, blood flow, and the presence of pathology, the dynamic images provide regional information about ventilation, pulsatile perfusion, and abnormalities. However, due to the ill-posedness of the inverse conductivity problem, EIT images have a coarse spatial resolution. One method of improving the resolution is to include prior information in the reconstruction. PURPOSE In this work, we propose a technique in which a statistical prior built from an anatomical atlas is used to postprocess EIT reconstructions of human chest data. The effectiveness of the method is demonstrated on data from two patients with cystic fibrosis. METHODS A direct reconstruction algorithm known as the D-bar method was used to compute a two-dimensional reconstruction of the conductivity distribution in the plane of the electrodes. Reconstructions using one step in an iterative (regularized) Newton's method were also computed for comparison. An anatomical atlas consisting of 1589 synthetic EIT images computed from X-ray computed tomography (CT) scans of 74 adult male subjects was computed for use as a statistical prior. The resolution of the D-bar images was then improved by maximizing the conditional probability density function of an image that is consistent with the a priori information and the statistical model. A new method to evaluate the accuracy of the EIT images using CT scans of the imaged patient as ground truth is presented. The novel approach is tested on data from two patients with cystic fibrosis. RESULTS AND CONCLUSIONS The D-bar images resulted in better structural similarity index measures (SSIM) and multiscale (MS) SSIM measures for both subjects using the mask or amplitude evaluation approach than the one-step (regularized) Newton's method. Further improvement was achieved using the Schur complement (SC) approach, with MS-SSIM values of 0.718 and 0.682 using SC evaluated with the mask and amplitude approach, respectively, for Patient 1, and MS-SSIM values of 0.726 and 0.692 using SC evaluated with the mask and amplitude approach, respectively, for Patient 2. The results from applying an anatomical atlas and statistical prior to EIT data from two patients with cystic fibrosis suggest that the spatial resolution of the EIT image can be improved to reveal pathology that may be difficult to discern in the original EIT image. The novel metric of evaluation is consistent with the appearance of improved spatial resolution and provides a new way to evaluate the accuracy of EIT reconstructions when a CT scan is available.
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Affiliation(s)
| | - Rafael Mikio Nakanishi
- Mechanical Engineering DepartmentPolytechnic School of the University of São PauloSão PauloSPBrazil
| | | | | | - Jari P. Kaipio
- Department of MathematicsUniversity of AucklandNew Zealand
- Department of Applied PhysicsUniversity of Eastern FinlandKuopioFinland
| | - Raul Gonzalez Lima
- Mechanical Engineering DepartmentPolytechnic School of the University of São PauloSão PauloSPBrazil
| | - Jennifer L. Mueller
- Department of Mathematics and School of Biomedical Engineering and the Department of Electrical and Computer EngineeringColorado State UniversityColoradoUSA
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Mi L, Chi Y, Yuan S, He H, Long Y, Frerichs I, Zhao Z. Effect of Prone Positioning With Individualized Positive End-Expiratory Pressure in Acute Respiratory Distress Syndrome Using Electrical Impedance Tomography. Front Physiol 2022; 13:906302. [PMID: 35845997 PMCID: PMC9282375 DOI: 10.3389/fphys.2022.906302] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 06/13/2022] [Indexed: 12/01/2022] Open
Abstract
Background: Positive end-expiratory pressure (PEEP) optimization during prone positioning remains under debate in acute respiratory distress syndrome (ARDS). This study aimed to investigate the effect of prone position on the optimal PEEP guided by electrical impedance tomography (EIT). Methods: We conducted a retrospective analysis on nineteen ARDS patients in a single intensive care unit. All patients underwent PEEP titration guided by EIT in both supine and prone positions. EIT-derived parameters, including center of ventilation (CoV), regional ventilation delay (RVD), percentage of overdistension (OD) and collapse (CL) were calculated. Optimal PEEP was defined as the PEEP level with minimal sum of OD and CL. Patients were divided into two groups: 1) Lower Optimal PEEPPP (LOP), where optimal PEEP was lower in the prone than in the supine position, and 2) Not-Lower Optimal PEEPPP (NLOP), where optimal PEEP was not lower in the prone compared with the supine position. Results: Eleven patients were classified as LOP (9 [8-9] vs. 12 [10-15] cmH2O; PEEP in prone vs. supine). In the NLOP group, optimal PEEP increased after prone positioning in four patients and remained unchanged in the other four patients. Patients in the LOP group had a significantly higher body mass index (26 [25-28] vs. 22 [17-25] kg/m2; p = 0.009) and lower ICU mortality (0/11 vs. 4/8; p = 0.018) compared with the NLOP group. Besides, PaO2/FiO2 increased significantly during prone positioning in the LOP group (238 [170-291] vs. 186 [141-195] mmHg; p = 0.042). CoV and RVD were also significantly improved during prone positioning in LOP group. No such effects were found in the NLOP group. Conclusion: Broad variability in optimal PEEP between supine and prone position was observed in the studied ARDS patients. Not all patients showed decreased optimal PEEP during prone positioning. Patients with higher body mass index exhibited lower optimal PEEP in prone position, better oxygenation and ventilation homogeneity.
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Affiliation(s)
- Liangyu Mi
- State Key Laboratory of Complex Severe and Rare Disease, Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Yi Chi
- State Key Laboratory of Complex Severe and Rare Disease, Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Siyi Yuan
- State Key Laboratory of Complex Severe and Rare Disease, Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Huaiwu He
- State Key Laboratory of Complex Severe and Rare Disease, Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
- *Correspondence: Huaiwu He, ; Yun Long,
| | - Yun Long
- State Key Laboratory of Complex Severe and Rare Disease, Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
- *Correspondence: Huaiwu He, ; Yun Long,
| | - Inéz Frerichs
- Department of Anesthesiology and Intensive Care Medicine, University Medical Center of Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - Zhanqi Zhao
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China
- Institute of Technical Medicine, Furtwangen University, VS-Schwenningen, Germany
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Li Z, Qin S, Chen C, Mei S, Yao Y, Zhao Z, Li W, Deng Y, Gao Y. Emerging Trends and Hot Spots of Electrical Impedance Tomography Applications in Clinical Lung Monitoring. Front Med (Lausanne) 2022; 8:813640. [PMID: 35174185 PMCID: PMC8841839 DOI: 10.3389/fmed.2021.813640] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 12/28/2021] [Indexed: 12/14/2022] Open
Abstract
Objective This study explores the emerging trends and hot topics concerning applications on electrical impedance tomography (EIT) in clinical lung monitoring. Methods Publications on EIT applications in clinical lung monitoring in 2001–2021 were extracted from the Web of Science Core Collection (WoSCC). The search strategy was “electrical impedance tomography” and “lung.” CiteSpace, a VOS viewer was used to study the citation characteristics, cooperation, and keyword co-occurrence. Moreover, co-cited reference clustering, structural variation analysis (SVA), and future research trends were presented. Results Six hundred and thirty-six publications were included for the final analysis. The global annual publications on clinical lung monitoring gradually increased in the last two decades. Germany contributes 32.2% of total global publications. University Medical Center Schleswig-Holstein (84 publications, cited frequency 2,205), Physiological Measurement (105 publications, cited frequency 2,056), and Inéz Frerichs (116 articles, cited frequency 3,609) were the institution, journal, and author with the largest number of article citations in the research field. “Electrical impedance tomography” (occurrences, 304), “mechanical ventilation” (occurrences, 99), and “acute respiratory distress syndrome” (occurrences, 67) were the top most three frequent keywords, “noninvasive monitoring” (Avg, pub, year: 2008.17), and “extracorporeal membrane oxygenation” (Avg, pub, year: 2019.60) were the earliest and latest keywords. The keywords “electrical impedance tomography” (strength 7.88) and co-cited reference “Frerichs I, 2017, THORAX” (strength 47.45) had the highest burst value. “Driving pressure,” “respiratory failure,” and “titration” are the three keywords still maintaining a high brush value until now. The largest and smallest cluster of the co-cited references are “obstructive lung diseases” (#0, size: 97) and “lung perfusion” (#20, size: 5). Co-cited reference “Frerichs I, 2017, THORAX” (modularity change rate: 98.49) has the highest structural variability. Categories with most and least interdisciplinary crossing are “ENGINEERING” and “CRITICAL CARE MEDICINE.” Conclusions EIT is a valuable technology for clinical lung monitoring, gradually converting from imaging techniques to the clinic. Research hot spots may continue monitoring techniques, the ventilation distribution of acute respiratory distress syndrome (ARDS), and respiratory therapy strategies. More diversified lung function monitoring studies, such as lung perfusion and interdisciplinary crossing, are potentially emerging research trends.
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Affiliation(s)
- Zhe Li
- Department of Critical Care Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Shaojie Qin
- Department of Critical Care Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Chen Chen
- Department of Critical Care Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Shuya Mei
- Department of Critical Care Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yulong Yao
- Department of Critical Care Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Zhanqi Zhao
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
| | - Wen Li
- Department of Critical Care Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- *Correspondence: Wen Li
| | - Yuxiao Deng
- Department of Critical Care Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Yuxiao Deng
| | - Yuan Gao
- Department of Critical Care Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Yuan Gao
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Hysteresis and Lung Recruitment in Acute Respiratory Distress Syndrome Patients: A CT Scan Study. Crit Care Med 2021; 48:1494-1502. [PMID: 32897667 DOI: 10.1097/ccm.0000000000004518] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
OBJECTIVES Hysteresis of the respiratory system pressure-volume curve is related to alveolar surface forces, lung stress relaxation, and tidal reexpansion/collapse. Hysteresis has been suggested as a means of assessing lung recruitment. The objective of this study was to determine the relationship between hysteresis, mechanical characteristics of the respiratory system, and lung recruitment assessed by a CT scan in mechanically ventilated acute respiratory distress syndrome patients. DESIGN Prospective observational study. SETTING General ICU of a university hospital. PATIENTS Twenty-five consecutive sedated and paralyzed patients with acute respiratory distress syndrome (age 64 ± 15 yr, body mass index 26 ± 6 kg/m, PaO2/FIO2 147 ± 42, and positive end-expiratory pressure 9.3 ± 1.4 cm H2O) were enrolled. INTERVENTIONS A low-flow inflation and deflation pressure-volume curve (5-45 cm H2O) and a sustained inflation recruitment maneuver (45 cm H2O for 30 s) were performed. A lung CT scan was performed during breath-holding pressure at 5 cm H2O and during the recruitment maneuver at 45 cm H2O. MEASUREMENTS AND MAIN RESULTS Lung recruitment was computed as the difference in noninflated tissue and in gas volume measured at 5 and at 45 cm H2O. Hysteresis was calculated as the ratio of the area enclosed by the pressure-volume curve and expressed as the hysteresis ratio. Hysteresis was correlated with respiratory system compliance computed at 5 cm H2O and the lung gas volume entering the lung during inflation of the pressure-volume curve (R = 0.749, p < 0.001 and R = 0.851, p < 0.001). The hysteresis ratio was related to both lung tissue and gas recruitment (R = 0.266, p = 0.008, R = 0.357, p = 0.002, respectively). Receiver operating characteristic analysis showed that the optimal cutoff value to predict lung tissue recruitment for the hysteresis ratio was 28% (area under the receiver operating characteristic curve, 0.80; 95% CI, 0.62-0.98), with sensitivity and specificity of 0.75 and 0.77, respectively. CONCLUSIONS Hysteresis of the respiratory system computed by low-flow pressure-volume curve is related to the anatomical lung characteristics and has an acceptable accuracy to predict lung recruitment.
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Hsu HJ, Chang HT, Zhao Z, Wang PH, Zhang JH, Chen YS, Frerichs I, Möller K, Fu F, Hsu HS, Chuang SP, Hsia HY, Yen DHT. Positive end-expiratory pressure titration with electrical impedance tomography and pressure-volume curve: a randomized trial in moderate to severe ARDS. Physiol Meas 2021; 42:014002. [PMID: 33361553 DOI: 10.1088/1361-6579/abd679] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE The aim of the study was to compare titration of positive end-expiratory pressure (PEEP) with electrical impedance tomography (EIT) and with ventilator-embedded pressure-volume (PV) loop in moderate to severe acute respiratory distress syndrome (ARDS). APPROACH Eighty-seven moderate to severe ARDS patients (arterial oxygen partial pressure to fractional inspired oxygen ratio, PaO2/FiO2 ≤ 200 mmHg) were randomized to either EIT group (n = 42) or PV group (n = 45). All patients received identical medical care using the same general support guidelines and protective mechanical ventilation. In the EIT group, the selected PEEP equaled the airway pressure at the intercept between cumulated collapse and overdistension percentages curves and in the PV group, at the pressure where maximal hysteresis was reached. MAIN RESULTS Baseline characteristics and settings were comparable between the groups. After optimization, PEEP was significantly higher in the PV group (17.4 ± 1.7 versus 16.2 ± 2.6 cmH2O, PV versus EIT groups, p = 0.02). After 48 h, driving pressure was significantly higher in the PV group (12.4 ± 3.6 versus 10.9 ± 2.5 cmH2O, p = 0.04). Lung mechanics and oxygenation were better in the EIT group but did not statistically differ between the groups. The survival rate was lower in the PV group (44.4% versus 69.0%, p = 0.02; hazard ratio 2.1, confidence interval 1·1-3.9). None of the other pre-specified exploratory clinical endpoints were significantly different. SIGNIFICANCE In moderate to severe ARDS, PEEP titration guided with EIT, compared with PV curve, might be associated with improved driving pressure and survival rate. TRIAL REGISTRATION NCT03112512, 13 April, 2017.
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Affiliation(s)
- Hui-Ju Hsu
- Institute of Emergency and Critical Care Medicine, National Yang-Ming University, Taipei, Taiwan. Department of Internal Medicine, Far Eastern Memorial Hospital, Taipei, Taiwan
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Qadri SK, Ng P, Toh TSW, Loh SW, Tan HL, Lin CB, Fan E, Lee JH. Critically Ill Patients with COVID-19: A Narrative Review on Prone Position. Pulm Ther 2020; 6:233-246. [PMID: 33085052 PMCID: PMC7575418 DOI: 10.1007/s41030-020-00135-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 09/26/2020] [Indexed: 01/08/2023] Open
Abstract
INTRODUCTION Prone position is known to improve mortality in patients with acute respiratory distress syndrome (ARDS). The impact of prone position in critically ill patients with coronavirus disease of 2019 (COVID-19) remains to be determined. In this review, we describe the mechanisms of action of prone position, systematically appraise the current experience of prone position in COVID-19 patients, and highlight unique considerations for prone position practices during this pandemic. METHODS For our systematic review, we searched PubMed, Scopus and EMBASE from January 1, 2020, to April 16, 2020. After completion of our search, we became aware of four relevant publications during article preparation that were published in May and June 2020, and these studies were reviewed for eligibility and inclusion. We included all studies reporting clinical characteristics of patients admitted to the hospital with COVID-19 disease who received respiratory support with high-flow nasal cannula, or noninvasive or mechanical ventilation and reported the use of prone position. The full text of eligible articles was reviewed, and data regarding study design, patient characteristics, interventions and outcomes were extracted. RESULTS We found seven studies (total 1899 patients) describing prone position in COVID-19. Prone position has been increasingly used in non-intubated patients with COVID-19; studies show high tolerance and improvement in oxygenation and lung recruitment. Published studies lacked a description of important clinical outcomes (e.g., mortality, duration of mechanical ventilation). CONCLUSIONS Based on the findings of our review, we recommend prone position in patients with moderate to severe COVID-19 ARDS as per existing guidelines. A trial of prone position should be considered for non-intubated COVID-19 patients with hypoxemic respiratory failure, as long as this does not result in a delay in intubation.
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Affiliation(s)
- Syeda Kashfi Qadri
- Children's Intensive Care Unit, Department of Pediatric Subspecialties, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore, 229899, Singapore.
- Duke NUS Medical School, 8 College Road, Singapore, 169857, Singapore.
| | - Priscilla Ng
- Duke NUS Medical School, 8 College Road, Singapore, 169857, Singapore
| | - Theresa Shu Wen Toh
- Department of Pediatrics, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore, 229899, Singapore
| | - Sin Wee Loh
- Department of Pediatrics, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore, 229899, Singapore
| | - Herng Lee Tan
- Children's Intensive Care Unit, Department of Pediatric Subspecialties, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore, 229899, Singapore
| | - Cheryl Bin Lin
- Children's Intensive Care Unit, Department of Pediatric Subspecialties, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore, 229899, Singapore
| | - Eddy Fan
- Interdepartmental Division of Critical Care Medicine, University of Toronto, 204 Victoria Street, 4th Floor, Room 411, Toronto, ON, M5B1T8, Canada
| | - Jan Hau Lee
- Children's Intensive Care Unit, Department of Pediatric Subspecialties, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore, 229899, Singapore
- Duke NUS Medical School, 8 College Road, Singapore, 169857, Singapore
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Zhao Z, Fu F, Frerichs I. Thoracic electrical impedance tomography in Chinese hospitals: a review of clinical research and daily applications. Physiol Meas 2020; 41:04TR01. [PMID: 32197257 DOI: 10.1088/1361-6579/ab81df] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Chinese scientists and researchers have a long history with electrical impedance tomography (EIT), which can be dated back to the 1980s. No commercial EIT devices for chest imaging were available until the year 2014 when the first device received its approval from the China Food and Drug Administration. Ever since then, clinical research and daily applications have taken place in Chinese hospitals. Up to this date (2019.11) 47 hospitals have been equipped with 50 EIT devices. Twenty-three SCI publications are recorded and a further 21 clinical trials are registered. Thoracic EIT is mainly used in patients before or after surgery, or in intensive care units (ICU). Application fields include the development of strategies for protective lung ventilation (e.g. tidal volume and positive end-expiratory pressure (PEEP) titration, recruitment, choice of ventilation mode and weaning from ventilator), regional lung perfusion monitoring, perioperative monitoring, and potential feedback for rehabilitation. The main challenges for promoting clinical use of EIT are the financial cost and the education of personnel. In this review, the past, present and future of EIT in China are introduced and discussed.
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Affiliation(s)
- Zhanqi Zhao
- Department of Biomedical Engineering, Fourth Military Medical University, No. 169 Changle West Road, Xincheng District, Xi'an 710005 People's Republic of China. Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
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Influence of different PEEP levels on electrical impedance tomography findings in patients under general anesthesia ventilated in the lateral decubitus position. J Clin Monit Comput 2020; 34:311-318. [PMID: 31062131 PMCID: PMC7223527 DOI: 10.1007/s10877-019-00318-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 04/30/2019] [Indexed: 12/12/2022]
Abstract
To determine the effect of various PEEP levels on electrical impedance tomography (EIT) measured differences in regional ventilation, hemodynamics, lung mechanics and parameters of alveolar gas exchange. Thirty three patients scheduled for elective urologic surgery in general anesthesia in lateral decubitus position were randomized into three groups-PEEP 0, 5 and 10 mbar. EIT recording, arterial blood gas analysis and hemodynamic parameters were captured at three timepoints-before induction (T0), 5 min after lateral positioning (T1) and 90 min after positioning (T2). Dynamic compliance (Cdyn) was measured at T1 and T2. Offline EIT data analysis was performed to calculate EIT derived parameters of ventilation distribution. Patients ventilated with PEEP of 10 mbar had a significantly lower A-a (alveolo arterial) gradient over measurements and symmetrical distribution of ventilation measured by EIT. There was no significant difference in Cdyn, center of ventilation indices and inhomogeneity index between groups. There was no difference of mean arterial pressure, cardiac index and heart rate between groups. Patients with 5 mbar of PEEP had higher stroke volume index compared to 0 and 10 mbar at baseline and over measurements. Nondependent/dependent TV ratio as well as global inhomogeneity index were correlated with A-a gradient. Dynamic compliance showed no correlation to A-a gradient. In our study, a PEEP level of 10 mbar improved alveolar gas exchange without compromising hemodynamic stability in patients mechanically ventilated in the lateral decubitus position. EIT measured parameters may be used to determine optimal ventilation parameters in these patients with inhomogeneous lung mechanics. Further studies are needed in patients with various lung pathologies.
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Zhao Z, Chang MY, Frerichs I, Zhang JH, Chang HT, Gow CH, Möller K. Regional air trapping in acute exacerbation of obstructive lung diseases measured with electrical impedance tomography: a feasibility study. Minerva Anestesiol 2019; 86:172-180. [PMID: 31808658 DOI: 10.23736/s0375-9393.19.13732-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND Since bronchial abnormalities often exhibit spatial non-uniformity which may be not correctly assessed by conventional global lung function measures, regional information may help to characterize the disease progress. We hypothesized that regional air trapping during mechanical ventilation could be characterized by regional end-expiratory flow (EEF) derived from electrical impedance tomography (EIT). METHODS Twenty-five patients suffering from chronic obstructive pulmonary disease (COPD grade 3 or 4) or severe asthma with acute exacerbation were examined prospectively. Patients were ventilated under assist-control mode. EIT measurements were conducted before and one hour after inhaled combined corticosteroid and long-acting β2 agonist, on two consecutive days. Regional EEF was calculated as derivative of relative impedance for every image pixel in the lung regions. The results were normalized to global flow values measured by the ventilator. RESULTS Regional and global EEF were highly correlated (P<0.00001) and regional effects of medication and disease progression were visible in the regional EEF maps. The sums of regional EEF in lung regions were 3.8 [2.0, 5.1] and 3.6 [1.9, 4.5] L/min in COPD patients before and after medication (median [lower, upper quartiles]; P=0.37). The corresponding values in asthma patients were 3.0 [2.5, 4.2] and 2.2 [1.7, 3.2] L/min (P<0.05). Histograms of regional EEF showed high spatial heterogeneity of EEF before medication. After one day of treatment, the histograms exhibited less heterogeneous and a decrease in EEF level. CONCLUSIONS Regional EEF characterizes air trapping and intrinsic PEEP, which could provide diagnostic information for monitoring the disease progress during treatment.
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Affiliation(s)
- Zhanqi Zhao
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China.,Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
| | - Mei-Yun Chang
- Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei City, Taiwan
| | - Inéz Frerichs
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Center of Schleswig-Holstein Campus, Kiel, Germany
| | - Jia-Hao Zhang
- Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei City, Taiwan
| | - Hou-Tai Chang
- Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei City, Taiwan
| | - Chien-Hung Gow
- Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei City, Taiwan - .,Department of Healthcare Information and Management, Ming-Chuan University, Taoyuan, Taiwan
| | - Knut Möller
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
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12
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Frerichs I, Zhao Z. Electrical impedance tomography for chest imaging in acute respiratory failure. Eur Respir J 2019; 54:54/4/1901497. [PMID: 31672905 DOI: 10.1183/13993003.01497-2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Accepted: 07/30/2019] [Indexed: 11/05/2022]
Affiliation(s)
- Inéz Frerichs
- Dept of Anaesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Zhanqi Zhao
- Dept of Biomedical Engineering, Fourth Military Medical University, Xi'an, China.,Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
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13
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Zhao Z, Lee LC, Chang MY, Frerichs I, Chang HT, Gow CH, Hsu YL, Möller K. The incidence and interpretation of large differences in EIT-based measures for PEEP titration in ARDS patients. J Clin Monit Comput 2019; 34:1005-1013. [PMID: 31587120 DOI: 10.1007/s10877-019-00396-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 09/26/2019] [Indexed: 12/18/2022]
Abstract
Positive end-expiratory pressure (PEEP) can be titrated by electrical impedance tomography (EIT). The aim of the present study was to examine the performance of different EIT measures during PEEP trials with the aim of identifying "optimum" PEEP and to provide possible interpretations of largely diverging results. After recruitment (maximum plateau pressure 35 cmH2O), decremental PEEP trial with steps of 2 cmH2O and duration of 2 min per step was performed. Ventilation gain and loss, the global inhomogeneity (GI) index, trend of end-expiratory lung impedance (EELI) and regional compliance (Creg) for estimation of overdistension and collapse were calculated. Largely diverging results of PEEP selection among the measures were defined as differences ≥ 4 PEEP steps (i.e. ≥ 8 cmH2O). In 30 ARDS patients we examined so far, 3 patients showed significant differences in PEEP selections. Overdistension and collapse estimation based on Creg tended to select lower PEEP while the GI index and EELI trend suggested higher PEEP settings. Regional inspiration times were heterogeneous indicating that the assumption of a uniform driving pressure in the calculation of Creg may not be valid. Judging by the predominant ventilation distribution in the most dependent regions, these patients were non-recruitable with the applied recruitment method or pressure levels. The existence of differences in the recommended PEEP among the analyzed EIT measures might be an indicator of non-recruitable lungs and heterogeneous airway resistances. In these extreme cases, the largely diverging results may prompt the attending clinician to develop individual ventilation strategies.Clinical Trial Registration Registration number NCT03112512, https://clinicaltrials.gov/ Registered 13 April 2017.
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Affiliation(s)
- Zhanqi Zhao
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China.,Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
| | - Li-Chung Lee
- Department of Internal Medicine, Far Eastern Memorial Hospital, No. 21, Sec. 2, Nanya S. Rd., Banciao Dist., New Taipei City, Taiwan
| | - Mei-Yun Chang
- Department of Internal Medicine, Far Eastern Memorial Hospital, No. 21, Sec. 2, Nanya S. Rd., Banciao Dist., New Taipei City, Taiwan
| | - Inez Frerichs
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre of Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - Hou-Tai Chang
- Department of Internal Medicine, Far Eastern Memorial Hospital, No. 21, Sec. 2, Nanya S. Rd., Banciao Dist., New Taipei City, Taiwan.
| | - Chien-Hung Gow
- Department of Internal Medicine, Far Eastern Memorial Hospital, No. 21, Sec. 2, Nanya S. Rd., Banciao Dist., New Taipei City, Taiwan
| | - Yeong-Long Hsu
- Department of Internal Medicine, Far Eastern Memorial Hospital, No. 21, Sec. 2, Nanya S. Rd., Banciao Dist., New Taipei City, Taiwan. .,Department of Healthcare Management, College of Medical Technology and Nursing, Yuanpei University of Medical Technology, No. 306 Yuanpei Street, Hsinchu, Taiwan.
| | - Knut Möller
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
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14
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Electrical Impedance Tomography for Cardio-Pulmonary Monitoring. J Clin Med 2019; 8:jcm8081176. [PMID: 31394721 PMCID: PMC6722958 DOI: 10.3390/jcm8081176] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/05/2019] [Accepted: 08/06/2019] [Indexed: 12/14/2022] Open
Abstract
Electrical impedance tomography (EIT) is a bedside monitoring tool that noninvasively visualizes local ventilation and arguably lung perfusion distribution. This article reviews and discusses both methodological and clinical aspects of thoracic EIT. Initially, investigators addressed the validation of EIT to measure regional ventilation. Current studies focus mainly on its clinical applications to quantify lung collapse, tidal recruitment, and lung overdistension to titrate positive end-expiratory pressure (PEEP) and tidal volume. In addition, EIT may help to detect pneumothorax. Recent studies evaluated EIT as a tool to measure regional lung perfusion. Indicator-free EIT measurements might be sufficient to continuously measure cardiac stroke volume. The use of a contrast agent such as saline might be required to assess regional lung perfusion. As a result, EIT-based monitoring of regional ventilation and lung perfusion may visualize local ventilation and perfusion matching, which can be helpful in the treatment of patients with acute respiratory distress syndrome (ARDS).
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15
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Cui Y, Cao R, Wang Y, Li G. Lung Recruitment Maneuvers for ARDS Patients: A Systematic Review and Meta-Analysis. Respiration 2019; 99:264-276. [PMID: 31330508 DOI: 10.1159/000501045] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 05/16/2019] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Lung recruitment maneuvers (LRMs) may reduce mortality and improve oxygenation in patients with acute respiratory distress syndrome (ARDS). However, the existing literature provides controversial conclusions. OBJECTIVES To determine whether LRMs have benefits on ARDS patients. Searching Methods: We searched relevant studies in PubMed, EMBASE, Medline, and the Cochrane Library up to May 2018. We considered for inclusion all prospective and randomized controlled trials which compared LRMs and non-LRM in adult patients with ARDS. We collected data about in-hospital mortality, 28-day mortality, the length of ICU and hospital stay, PaO2/FiO2, and FiO2. MAIN RESULTS Ten trials including 3,025 patients were analyzed. No significant difference was found in the hospital and 28-day mortality, as well as the length of ICU stay and oxygen requirement, even undergoing subgroup analysis. However, the results of this meta-analysis showed a significant benefit of LRMs for shortening the length of hospital stay (mean difference, MD = -1.75; 95% CI, -3.40 to -0.09; p = 0.04; p for heterogeneity = 0.3, I2 = 18%) and improving PaO2/FiO2 ratio on the third day (MD = 52.72; 95% CI, 18.77-86.67; p = 0.002), but with extremely high heterogeneity (p for heterogeneity <0.0001, I2 = 99%). CONCLUSION LRMs do not produce significant reduction of mortality in patients with ARDS but may shorten the length of hospital stay and improve oxygenation on the third day. However, the results must be interpreted cautiously as most studies were on multiple intervention exposures.
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Affiliation(s)
- Yu Cui
- Department of Anesthesiology, Chengdu Women's and Children's Central Hospital, Chengdu, China,
| | - Rong Cao
- Department of Anesthesiology, Chengdu Women's and Children's Central Hospital, Chengdu, China
| | - Yu Wang
- Department of Anesthesiology, AVIC 363 Hospital, Chengdu, China
| | - Gen Li
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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16
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Freynet A, Decloedt C, Grandet P, Ouattara A, Fleureau C. Décubitus ventral et kinésithérapie respiratoire : y a-t-il une indication ? Description d’un cas clinique. MEDECINE INTENSIVE REANIMATION 2019. [DOI: 10.3166/rea-2019-0107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Contexte : Le décubitus ventral (DV) est appliqué dans un objectif de recrutement alvéolaire, dans le cadre de syndrome de détresse respiratoire aiguë (SDRA). Le DV mobilise parfois des sécrétions bronchiques, interrogeant l’intérêt d’une kinésithérapie de désencombrement.
Matériel et méthode : Une femme de 43 ans, myopathe de Steinert, est hospitalisée pour une insuffisance hépatique aiguë. À j3, elle présente une pneumopathie d’inhalation, suivie d’un SDRA. Le positionnement en DV est réalisé, mobilisant des sécrétions bronchiques. Une séance de kinésithérapie respiratoire est alors appliquée.
Résultats : Après la mise en DVet la séance de kinésithérapie, la quantité de sécrétions recueillies est de 2,4 g. Le rapport entre la pression partielle en oxygène et la fraction inspirée en oxygène (PaO2/FiO2) s’améliore, passant de 64 à 180 au bout de 11 heures de DV. La pression motrice et la pression de plateau sont restées inférieures aux valeurs délétères au cours de la séance de kinésithérapie, celle-ci n’ayant pas généré d’hypoxie pendant ou après la séance.
Discussion : Le positionnement en DV libère les parties postérieures des poumons, permettant une amélioration du rapport PaO2/FiO2. La clairance mucociliaire a été améliorée, mais il n’est pas possible de discriminer les effets du DVou de la kinésithérapie. Dans la littérature, la kinésithérapie respiratoire n’a pas montré son efficacité pour ces patients, même si aucun effet délétère n’a été observé à travers ce cas clinique. Les risques de dé-recrutement alvéolaire restent importants.
Conclusion : Il est difficile de recommander en pratique courante la kinésithérapie respiratoire de désencombrement en DV. Des études ultérieures sont nécessaires, dans un objectif de recherche centré plutôt sur le recrutement alvéolaire que sur le désencombrement, chez ces patients fragiles.
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17
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de Castro Martins T, Sato AK, de Moura FS, de Camargo EDLB, Silva OL, Santos TBR, Zhao Z, Möeller K, Amato MBP, Mueller JL, Lima RG, de Sales Guerra Tsuzuki M. A Review of Electrical Impedance Tomography in Lung Applications: Theory and Algorithms for Absolute Images. ANNUAL REVIEWS IN CONTROL 2019; 48:442-471. [PMID: 31983885 PMCID: PMC6980523 DOI: 10.1016/j.arcontrol.2019.05.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Electrical Impedance Tomography (EIT) is under fast development, the present paper is a review of some procedures that are contributing to improve spatial resolution and material properties accuracy, admitivitty or impeditivity accuracy. A review of EIT medical applications is presented and they were classified into three broad categories: ARDS patients, obstructive lung diseases and perioperative patients. The use of absolute EIT image may enable the assessment of absolute lung volume, which may significantly improve the clinical acceptance of EIT. The Control Theory, the State Observers more specifically, have a developed theory that can be used for the design and operation of EIT devices. Electrode placement, current injection strategy and electrode electric potential measurements strategy should maximize the number of observable and controllable directions of the state vector space. A non-linear stochastic state observer, the Unscented Kalman Filter, is used directly for the reconstruction of absolute EIT images. Historically, difference images were explored first since they are more stable in the presence of modelling errors. Absolute images require more detailed models of contact impedance, stray capacitance and properly refined finite element mesh where the electric potential gradient is high. Parallelization of the forward program computation is necessary since the solution of the inverse problem often requires frequent solutions of the forward problem. Several reconstruction algorithms benefit by the Bayesian inverse problem approach and the concept of prior information. Anatomic and physiologic information are used to form the prior information. An already tested methodology is presented to build the prior probability density function using an ensemble of CT scans and in vivo impedance measurements. Eight absolute EIT image algorithms are presented.
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Affiliation(s)
| | - André Kubagawa Sato
- Computational Geometry Laboratory, Escola Politécnica da Universidade de São Paulo, Brazil
| | - Fernando Silva de Moura
- Universidade Federal do ABC, Center of Engineering, Modeling and Applied Social Sciences, Brazil
| | | | - Olavo Luppi Silva
- Universidade Federal do ABC, Center of Engineering, Modeling and Applied Social Sciences, Brazil
| | | | - Zhanqi Zhao
- Institute of Technical Medicine, Furtwangen University, Germany
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Knut Möeller
- Institute of Technical Medicine, Furtwangen University, Germany
| | - Marcelo Brito Passos Amato
- Respiratory Intensive Care Unit, Pulmonary Division, Hospital das Clínicas, Universidade de São Paulo, Brazil
| | - Jennifer L Mueller
- Department of Mathematics, and School of Biomedical Engineering, Colorado State University, United States of America
| | - Raul Gonzalez Lima
- Department of Mechanical Engineering, Escola Politécnica da Universidade de São Paulo, Brazil
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18
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Clinical Scenarios of the Application of Electrical Impedance Tomography in Paediatric Intensive Care. Sci Rep 2019; 9:5362. [PMID: 30926828 PMCID: PMC6441075 DOI: 10.1038/s41598-019-41774-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 12/20/2018] [Indexed: 11/25/2022] Open
Abstract
EIT is a radiation-free functional modality that enables bedside imaging and monitoring of lung function and expansion. Clinical interest in this method has been driven by the need for bedside monitoring of the dynamics of the lungs and the effects of ventilatory manoeuvres, including changes in ventilator settings, suctioning, chest drains, positioning and physiotherapy. We aimed to describe the use of Electrical Impedance Tomography (EIT) as a clinical tool in a tertiary Paediatric Intensive Care unit. Children requiring intensive care with a variety of clinical conditions had an electrode belt with 16 electrodes wrapped around the chest, which sequentially applied a small alternating current from each electrode pair. The signal gives information on both real time, regional, global, and relative data. With the correct application, and understanding of the monitor, much clinical information can be gained, with potentially significant patient benefit. We present the clinical use of EIT in six conditions: Asthma, Ventilation weaning and expansion recoil, Sequential Lobar Collapse, Targeted Physiotherapy, Pleural Effusion assessment, and PEEP optimisation. Screenshots and analyses are offered displaying the pragmatic use of this technology. Electrical Impedance Tomography is a clinically useful tool on the Paediatric Intensive Care unit. It allows monitoring of a patient’s respiratory function in ways which are not possible through any other means. An understanding of respiratory physiology will allow use of this information to improve patient outcomes.
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19
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Shono A, Kotani T. Clinical implication of monitoring regional ventilation using electrical impedance tomography. J Intensive Care 2019; 7:4. [PMID: 30680219 PMCID: PMC6339287 DOI: 10.1186/s40560-019-0358-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 01/09/2019] [Indexed: 11/10/2022] Open
Abstract
Mechanical ventilation can initiate ventilator-associated lung injury (VALI) and contribute to the development of multiple organ dysfunction. Although a lung protective strategy limiting both tidal volume and plateau pressure reduces VALI, uneven intrapulmonary gas distribution is still capable of increasing regional stress and strain, especially in non-homogeneous lungs, such as during acute respiratory distress syndrome. Real-time monitoring of regional ventilation may prevent inhomogeneous ventilation, leading to a reduction in VALI. Electrical impedance tomography (EIT) is a technique performed at the patient's bedside. It is noninvasive and radiation-free and provides dynamic tidal images of gas distribution. Studies have reported that EIT provides useful information both in animal and clinical studies during mechanical ventilation. EIT has been shown to be useful during lung recruitment, titration of positive end-expiratory pressure, lung volume estimation, and evaluation of homogeneity of gas distribution in a single EIT measure or in combination with multiple EIT measures. EIT-guided mechanical ventilation preserved the alveolar architecture and maintained oxygenation and lung mechanics better than low-tidal volume ventilation in animal models. However, careful assessment is required for data analysis owing to the limited understanding of the results of EIT interpretation. Previous studies indicate monitoring regional ventilation by EIT is feasible in the intensive care setting and has potential to lead to lung protective ventilation. Further clinical studies are warranted to evaluate whether monitoring of regional ventilation using EIT can shorten the duration of ventilation or improve mortality in patients with acute respiratory distress syndrome.
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Affiliation(s)
- Atsuko Shono
- 1Department of Anesthesiology, Shimane University, 89-1 Enya-cho, Izumo City, Shimane 693-8501 Japan
| | - Toru Kotani
- 2Department of Intensive Care Medicine, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142-8666 Japan
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20
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Zhao Z, Chu CC, Chang MY, Chang HT, Hsu YL. Management of adult-onset methylmalonic acidemia with hypotonia and acute respiratory failure: A case report. Medicine (Baltimore) 2018; 97:e11162. [PMID: 29924026 PMCID: PMC6024463 DOI: 10.1097/md.0000000000011162] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
RATIONALE Methylmalonic acidemia (MMA) is an autosomal recessive disease of organic acidemia. PATIENT CONCERNS We report a 26-year-old male who presented with metabolic acidosis, acute renal failure required hemodialysis and acute respiratory failure required mechanical ventilation support. Progressive hypotonia of muscles made weaning from mechanical ventilator difficult. DIAGNOSES High level of serum methylmalonic acid and the mut genotype sequences confirmed the diagnosis of this adult-onset MMA. Two mut genotype sequences were found by analyzing all coding exons and exon-intron junctions. One genotype was well documented (Exon 6 Mutation, c. 1280G>A. p. G427D, heterozygous). The other mut genotype sequence had never been reported elsewhere (Intron 6 Novel, c. 1333-13_c. 1333-8delTTTTTC, heterozygous). INTERVENTIONS Diet modification, medication, regular hemodialysis and physical rehabilitation. Weaning strategy adjusted with help of electrical impedance tomography. OUTCOMES The muscle power of the patient gradually recovered. Extubation of the patient was successful and he was discharged without oxygen required. LESSONS This case gives us the lesson that MMA can be newly diagnosed in adult patient. A new mut genotype sequence was discovered. The use of electrical impedance tomography to select a suitable method for inspiratory muscle training was possible and useful.
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Affiliation(s)
- Zhanqi Zhao
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
| | | | | | - Hao-Tai Chang
- Division of Chest Medicine, Department of Internal Medicine, Far Eastern Memorial Hospital, Ban-Chiao District, New Taipei City, Taiwan
| | - Yeong-Long Hsu
- Division of Chest Medicine, Department of Internal Medicine, Far Eastern Memorial Hospital, Ban-Chiao District, New Taipei City, Taiwan
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21
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Heines SJH, Strauch U, van de Poll MCG, Roekaerts PMHJ, Bergmans DCJJ. Clinical implementation of electric impedance tomography in the treatment of ARDS: a single centre experience. J Clin Monit Comput 2018; 33:291-300. [PMID: 29845479 PMCID: PMC6420412 DOI: 10.1007/s10877-018-0164-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 05/27/2018] [Indexed: 11/24/2022]
Abstract
To report on our clinical experience using EIT in individualized PEEP titration in ARDS. Using EIT assessment, we optimized PEEP settings in 39 ARDS patients. The EIT PEEP settings were compared with the physicians' PEEP settings and the PEEP settings according to the ARDS network. We defined a PEEP difference equal to or greater than 4 cm H2O as clinically relevant. Changes in lung compliance and PaO2/FiO2-ratio were compared in patients with EIT-based PEEP adjustments and in patients with unaltered PEEP. In 28% of the patients, the difference in EIT-based PEEP and physician-PEEP was clinically relevant; in 36%, EIT-based PEEP and physician-PEEP were equal. The EIT-based PEEP disagreed with the PEEP settings according to the ARDS network. Adjusting PEEP based upon EIT led to a rapid increase in lung compliance and PaO2/FiO2-ratio. However, this increase was also observed in the group where the PEEP difference was less than 4 cm H2O. We hypothesize that this can be attributed to the alveolar recruitment during the PEEP trial. EIT based individual PEEP setting appears to be a promising method to optimize PEEP in ARDS patients. The clinical impact, however, remains to be established.
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Affiliation(s)
- Serge J H Heines
- Department of Intensive Care, Maastricht University Medical Centre+, P. Debyelaan 25, 6229HX, Maastricht, The Netherlands.
| | - Ulrich Strauch
- Department of Intensive Care, Maastricht University Medical Centre+, P. Debyelaan 25, 6229HX, Maastricht, The Netherlands
| | - Marcel C G van de Poll
- Department of Intensive Care, Maastricht University Medical Centre+, P. Debyelaan 25, 6229HX, Maastricht, The Netherlands.,Department of Surgery, Maastricht University Medical Centre+, P. Debyelaan 25, 6229HX, Maastricht, The Netherlands.,School of Nutrition and Translational Research in Medicine (NUTRIM), Maastricht University, P.O. Box 616, 6200MD, Maastricht, The Netherlands
| | - Paul M H J Roekaerts
- Department of Intensive Care, Maastricht University Medical Centre+, P. Debyelaan 25, 6229HX, Maastricht, The Netherlands.,Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, P.O. Box 616, 6200MD, Maastricht, The Netherlands
| | - Dennis C J J Bergmans
- Department of Intensive Care, Maastricht University Medical Centre+, P. Debyelaan 25, 6229HX, Maastricht, The Netherlands
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22
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Ferrando C, Tusman G, Suarez-Sipmann F, León I, Pozo N, Carbonell J, Puig J, Pastor E, Gracia E, Gutiérrez A, Aguilar G, Belda FJ, Soro M. Individualized lung recruitment maneuver guided by pulse-oximetry in anesthetized patients undergoing laparoscopy: a feasibility study. Acta Anaesthesiol Scand 2018; 62:608-619. [PMID: 29377061 DOI: 10.1111/aas.13082] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 12/21/2017] [Accepted: 01/02/2018] [Indexed: 01/27/2023]
Abstract
BACKGROUND We conducted this study to test whether pulse-oximetry hemoglobin saturation (SpO2 ) can personalize the implementation of an open-lung approach during laparoscopy. Thirty patients with SpO2 ≥ 97% on room-air before anesthesia were studied. After anesthesia and capnoperitoneum the FIO2 was reduced to 0.21. Those patients whose SpO2 decreased below 97% - an indication of shunt related to atelectasis - completed the following phases: (1) First recruitment maneuver (RM), until reaching lung's opening pressure, defined as the inspiratory pressure level yielding a SpO2 ≥ 97%; (2) decremental positive end-expiratory (PEEP) titration trial until reaching lung's closing pressure defined as the PEEP level yielding a SpO2 < 97%; (3) second RM and, (4) ongoing ventilation with PEEP adjusted above the detected closing pressure. RESULTS When breathing air, in 24 of 30 patients SpO2 was < 97%, PaO2 /FIO2 ˂ 53.3 kPa and negative end-expiratory transpulmonary pressure (PTP-EE ). The mean (SD) opening pressures were found at 40 (5) and 33 (4) cmH2 O during the first and second RM, respectively (P < 0.001; 95% CI: 3.2-7.7). The closing pressure was found at 11 (5) cmH2 O. This SpO2 -guided approach increased PTP-EE (from -6.4 to 1.2 cmH2 O, P < 0.001) and PaO2 /FIO2 (from 30.3 to 58.1 kPa, P < 0.001) while decreased driving pressure (from 18 to 10 cmH2 O, P < 0.001). SpO2 discriminated the lung's opening and closing pressures with accuracy taking the reference parameter PTP-EE (area under the receiver-operating-curve of 0.89, 95% CI: 0.80-0.99). CONCLUSION The non-invasive SpO2 monitoring can help to individualize an open-lung approach, including all involved steps, from the identification of those patients who can benefit from recruitment, the identification of opening and closing pressures to the subsequent monitoring of an open-lung condition.
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Affiliation(s)
- C. Ferrando
- Department of Anaesthesiology and Critical Care; Hospital Clínico Universitario; Valencia Spain
- CIBER de Enfermedades Respiratorias; Instituto de Salud Carlos III; Madrid Spain
| | - G. Tusman
- Department of Anesthesiology; Hospital Privado de Comunidad Mar de Plata; Mar de Plata Argentina
| | - F. Suarez-Sipmann
- Department of Anaesthesiology and Critical Care; Hospital Clínico Universitario; Valencia Spain
- Deparment of Intensive Care; Hospital Universitario La Princesa; Madrid Spain
| | - I. León
- Department of Anaesthesiology and Critical Care; Hospital Clínico Universitario; Valencia Spain
| | - N. Pozo
- Department of Anaesthesiology and Critical Care; Hospital Clínico Universitario; Valencia Spain
| | - J. Carbonell
- Department of Anaesthesiology and Critical Care; Hospital Clínico Universitario; Valencia Spain
| | - J. Puig
- Department of Anaesthesiology and Critical Care; Hospital Clínico Universitario; Valencia Spain
| | - E. Pastor
- Department of Anaesthesiology and Critical Care; Hospital Clínico Universitario; Valencia Spain
| | - E. Gracia
- Department of Anaesthesiology and Critical Care; Hospital Clínico Universitario; Valencia Spain
| | - A. Gutiérrez
- Department of Anaesthesiology and Critical Care; Hospital Clínico Universitario; Valencia Spain
| | - G. Aguilar
- Department of Anaesthesiology and Critical Care; Hospital Clínico Universitario; Valencia Spain
| | - F. J. Belda
- Department of Anaesthesiology and Critical Care; Hospital Clínico Universitario; Valencia Spain
| | - M. Soro
- Department of Anaesthesiology and Critical Care; Hospital Clínico Universitario; Valencia Spain
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Zhao Z, Wang W, Zhang Z, Xu M, Frerichs I, Wu J, Moeller K. Influence of tidal volume and positive end-expiratory pressure on ventilation distribution and oxygenation during one-lung ventilation. Physiol Meas 2018; 39:034003. [DOI: 10.1088/1361-6579/aaaeb2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Dmytrowich J, Holt T, Schmid K, Hansen G. Mechanical ventilation guided by electrical impedance tomography in pediatric acute respiratory distress syndrome. J Clin Monit Comput 2017; 32:503-507. [DOI: 10.1007/s10877-017-0048-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 07/18/2017] [Indexed: 11/24/2022]
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