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Leali M, Marongiu I, Spinelli E, Chiavieri V, Perez J, Panigada M, Grasselli G, Mauri T. Absolute values of regional ventilation-perfusion mismatch in patients with ARDS monitored by electrical impedance tomography and the role of dead space and shunt compensation. Crit Care 2024; 28:241. [PMID: 39010228 PMCID: PMC11251389 DOI: 10.1186/s13054-024-05033-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Accepted: 07/11/2024] [Indexed: 07/17/2024] Open
Abstract
BACKGROUND Assessment of regional ventilation/perfusion (V'/Q) mismatch using electrical impedance tomography (EIT) represents a promising advancement for personalized management of the acute respiratory distress syndrome (ARDS). However, accuracy is still hindered by the need for invasive monitoring to calibrate ventilation and perfusion. Here, we propose a non-invasive correction that uses only EIT data and characterized patients with more pronounced compensation of V'/Q mismatch. METHODS We enrolled twenty-one ARDS patients on controlled mechanical ventilation. Cardiac output was measured invasively, and ventilation and perfusion were assessed by EIT. Relative V'/Q maps by EIT were calibrated to absolute values using the minute ventilation to invasive cardiac output (MV/CO) ratio (V'/Q-ABS), left unadjusted (V'/Q-REL), or corrected by MV/CO ratio derived from EIT data (V'/Q-CORR). The ratio between ventilation to dependent regions and perfusion reaching shunted units ( V D ' /QSHUNT) was calculated as an index of more effective hypoxic pulmonary vasoconstriction. The ratio between perfusion to non-dependent regions and ventilation to dead space units (QND/ V DS ' ) was calculated as an index of hypocapnic pneumoconstriction. RESULTS Our calibration factor correlated with invasive MV/CO (r = 0.65, p < 0.001), showed good accuracy and no apparent bias. Compared to V'/Q-ABS, V'/Q-REL maps overestimated ventilation (p = 0.013) and perfusion (p = 0.002) to low V'/Q units and underestimated ventilation (p = 0.011) and perfusion (p = 0.008) to high V'/Q units. The heterogeneity of ventilation and perfusion reaching different V'/Q compartments was underestimated. V'/Q-CORR maps eliminated all these differences with V'/Q-ABS (p > 0.05). HigherV D ' / Q SHUNT correlated with higher PaO2/FiO2 (r = 0.49, p = 0.025) and lower shunt fraction (ρ = - 0.59, p = 0.005). HigherQ ND / V DS ' correlated with lower PEEP (ρ = - 0.62, p = 0.003) and plateau pressure (ρ = - 0.59, p = 0.005). Lower values of both indexes were associated with less ventilator-free days (p = 0.05 and p = 0.03, respectively). CONCLUSIONS Regional V'/Q maps calibrated with a non-invasive EIT-only method closely approximate the ones obtained with invasive monitoring. Higher efficiency of shunt compensation improves oxygenation while compensation of dead space is less needed at lower airway pressure. Patients with more effective compensation mechanisms could have better outcomes.
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Affiliation(s)
- Marco Leali
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Ines Marongiu
- Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Elena Spinelli
- Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Valentina Chiavieri
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Joaquin Perez
- Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Mauro Panigada
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
- Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Giacomo Grasselli
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
- Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Tommaso Mauri
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy.
- Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
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Cui Z, Liu X, Qu H, Wang H. Technical Principles and Clinical Applications of Electrical Impedance Tomography in Pulmonary Monitoring. SENSORS (BASEL, SWITZERLAND) 2024; 24:4539. [PMID: 39065936 PMCID: PMC11281055 DOI: 10.3390/s24144539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 06/11/2024] [Accepted: 07/10/2024] [Indexed: 07/28/2024]
Abstract
Pulmonary monitoring is crucial for the diagnosis and management of respiratory conditions, especially after the epidemic of coronavirus disease. Electrical impedance tomography (EIT) is an alternative non-radioactive tomographic imaging tool for monitoring pulmonary conditions. This review proffers the current EIT technical principles and applications on pulmonary monitoring, which gives a comprehensive summary of EIT applied on the chest and encourages its extensive usage to clinical physicians. The technical principles involving EIT instrumentations and image reconstruction algorithms are explained in detail, and the conditional selection is recommended based on clinical application scenarios. For applications, specifically, the monitoring of ventilation/perfusion (V/Q) is one of the most developed EIT applications. The matching correlation of V/Q could indicate many pulmonary diseases, e.g., the acute respiratory distress syndrome, pneumothorax, pulmonary embolism, and pulmonary edema. Several recently emerging applications like lung transplantation are also briefly introduced as supplementary applications that have potential and are about to be developed in the future. In addition, the limitations, disadvantages, and developing trends of EIT are discussed, indicating that EIT will still be in a long-term development stage before large-scale clinical applications.
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Affiliation(s)
- Ziqiang Cui
- School of Electrical and Information Engineering, Tianjin University, Tianjin 300072, China; (X.L.); (H.Q.); (H.W.)
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Frerichs I, Händel C, Becher T, Schädler D. Sex differences in chest electrical impedance tomography findings. Physiol Meas 2024; 45:075005. [PMID: 38959902 DOI: 10.1088/1361-6579/ad5ef7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Accepted: 07/03/2024] [Indexed: 07/05/2024]
Abstract
Objective.Electrical impedance tomography (EIT) has been used to determine regional lung ventilation distribution in humans for decades, however, the effect of biological sex on the findings has hardly ever been examined. The aim of our study was to determine if the spatial distribution of ventilation assessed by EIT during quiet breathing was influenced by biological sex.Approach.219 adults with no known acute or chronic lung disease were examined in sitting position with the EIT electrodes placed around the lower chest (6th intercostal space). EIT data were recorded at 33 images/s during quiet breathing for 60 s. Regional tidal impedance variation was calculated in all EIT image pixels and the spatial distribution of the values was determined using the established EIT measures of centre of ventilation in ventrodorsal (CoVvd) and right-to-left direction (CoVrl), the dorsal and right fraction of ventilation, and ventilation defect score.Main results.After exclusion of one subject due to insufficient electrode contact, 218 data sets were analysed (120 men, 98 women) (age: 53 ± 18 vs 50 ± 16 yr (p= 0.2607), body mass index: 26.4 ± 4.0 vs 26.4 ± 6.6 kg m-2(p= 0.9158), mean ± SD). Highly significant differences in ventilation distribution were identified between men and women between the right and left chest sides (CoVrl: 47.0 ± 2.9 vs 48.8 ± 3.3% of chest diameter (p< 0.0001), right fraction of ventilation: 0.573 ± 0.067 vs 0.539 ± 0.071 (p= 0.0004)) and less significant in the ventrodorsal direction (CoVvd: 55.6 ± 4.2 vs 54.5 ± 3.6% of chest diameter (p= 0.0364), dorsal fraction of ventilation: 0.650 ± 0.121 vs 0.625 ± 0.104 (p= 0.1155)). Ventilation defect score higher than one was found in 42.5% of men but only in 16.6% of women.Significance.Biological sex needs to be considered when EIT findings acquired in upright subjects in a rather caudal examination plane are interpreted. Sex differences in chest anatomy and thoracoabdominal mechanics may explain the results.
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Affiliation(s)
- I Frerichs
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - C Händel
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - T Becher
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - D Schädler
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein, Campus Kiel, Kiel, Germany
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Gaulton TG, Xin Y, Victor M, Nova A, Cereda M. Imaging the pulmonary vasculature in acute respiratory distress syndrome. Nitric Oxide 2024; 147:6-12. [PMID: 38588918 PMCID: PMC11253040 DOI: 10.1016/j.niox.2024.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 03/21/2024] [Accepted: 04/03/2024] [Indexed: 04/10/2024]
Abstract
Acute respiratory distress syndrome (ARDS) is characterized by a redistribution of regional lung perfusion that impairs gas exchange. While speculative, experimental evidence suggests that perfusion redistribution may contribute to regional inflammation and modify disease progression. Unfortunately, tools to visualize and quantify lung perfusion in patients with ARDS are lacking. This review explores recent advances in perfusion imaging techniques that aim to understand the pulmonary circulation in ARDS. Dynamic contrast-enhanced computed tomography captures first-pass kinetics of intravenously injected dye during continuous scan acquisitions. Different contrast characteristics and kinetic modeling have improved its topographic measurement of pulmonary perfusion with high spatial and temporal resolution. Dual-energy computed tomography can map the pulmonary blood volume of the whole lung with limited radiation exposure, enabling its application in clinical research. Electrical impedance tomography can obtain serial topographic assessments of perfusion at the bedside in response to treatments such as inhaled nitric oxide and prone position. Ongoing technological improvements and emerging techniques will enhance lung perfusion imaging and aid its incorporation into the care of patients with ARDS.
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Affiliation(s)
- Timothy G Gaulton
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Department of Anesthesia, Critical Care and Pain Medicine, Harvard Medical School, Boston, MA, USA.
| | - Yi Xin
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Department of Anesthesia, Critical Care and Pain Medicine, Harvard Medical School, Boston, MA, USA
| | - Marcus Victor
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Department of Anesthesia, Critical Care and Pain Medicine, Harvard Medical School, Boston, MA, USA; Electronics Engineering Division, Aeronautics Institute of Technology, Sao Paulo, Brazil
| | - Alice Nova
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Department of Anesthesia, Critical Care and Pain Medicine, Harvard Medical School, Boston, MA, USA
| | - Maurizio Cereda
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Department of Anesthesia, Critical Care and Pain Medicine, Harvard Medical School, Boston, MA, USA
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Wang Q, He H, Yuan S, Jiang J, Chi Y, Long Y, Zhao Z. Early bedside detection of pulmonary perfusion defect by electrical impedance tomography after pulmonary endarterectomy. Pulm Circ 2024; 14:e12372. [PMID: 38699668 PMCID: PMC11063724 DOI: 10.1002/pul2.12372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 02/04/2024] [Accepted: 04/12/2024] [Indexed: 05/05/2024] Open
Abstract
Pulmonary endarterectomy (PEA) is the standard treatment for chronic thromboembolic pulmonary hypertension. However, it poses risks of perioperative vascular complications, which can lead to serious clinical outcomes. This study introduces a novel noninvasive and radiation-free clinical imaging tool, electrical impedance tomography (EIT), for real-time bedside assessment of lung perfusion after PEA. It identifies ventilation-perfusion mismatches arising from postoperative complications, particularly valuable for patients with hemodynamic instability, thus eliminating risks tied to CT room transfers. The article reports a case where EIT was used to identify an in-situ thrombosis post-PEA, marking the first such application. The emphasis is on early detection using EIT, which offers a promising approach for therapeutic interventions and improved postoperative evaluations.
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Affiliation(s)
- Qianlin Wang
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare DiseasesPeking Union Medical College Hospital, Chinese Academy of Medical SciencesBeijingChina
| | - Huaiwu He
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare DiseasesPeking Union Medical College Hospital, Chinese Academy of Medical SciencesBeijingChina
| | - Siyi Yuan
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare DiseasesPeking Union Medical College Hospital, Chinese Academy of Medical SciencesBeijingChina
| | - Jing Jiang
- Department of Critical Care MedicineChongqing General HospitalChongqingLiangjiang New AreaChina
| | - Yi Chi
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare DiseasesPeking Union Medical College Hospital, Chinese Academy of Medical SciencesBeijingChina
| | - Yun Long
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare DiseasesPeking Union Medical College Hospital, Chinese Academy of Medical SciencesBeijingChina
| | - Zhanqi Zhao
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare DiseasesPeking Union Medical College Hospital, Chinese Academy of Medical SciencesBeijingChina
- Institute of Technical MedicineFurtwangen UniversityVillingen‐SchwenningenGermany
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佘 林, 周 睿, 潘 盼, 李 展, 刘 继, 谢 菲. [Research progress on electrical impedance tomography in pulmonary perfusion]. SHENG WU YI XUE GONG CHENG XUE ZA ZHI = JOURNAL OF BIOMEDICAL ENGINEERING = SHENGWU YIXUE GONGCHENGXUE ZAZHI 2023; 40:1249-1254. [PMID: 38151950 PMCID: PMC10753299 DOI: 10.7507/1001-5515.202302025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 10/04/2023] [Indexed: 12/29/2023]
Abstract
Electrical impedance tomography (EIT) is an emerging technology for real-time monitoring based on the impedance differences of different tissues and organs in the human body. It has been initially applied in clinical research as well as disease diagnosis and treatment. Lung perfusion refers to the blood flow perfusion function of lung tissue, and the occurrence and development of many diseases are closely related to lung perfusion. Therefore, real-time monitoring of lung perfusion is particularly important. The application and development of EIT further promote the monitoring of lung perfusion, and related research has made great progress. This article reviews the principles of EIT imaging, lung perfusion imaging methods, and their clinical applications in recent years, with the aim of providing assistance to clinical and scientific researchers.
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Affiliation(s)
- 林君 佘
- 河南中医药大学 第一临床医学院(郑州 450000)The First Clinical Medical College, Henan University of Traditional Chinese Medicine, Zhengzhou 450000, P. R. China
| | - 睿 周
- 河南中医药大学 第一临床医学院(郑州 450000)The First Clinical Medical College, Henan University of Traditional Chinese Medicine, Zhengzhou 450000, P. R. China
| | - 盼 潘
- 河南中医药大学 第一临床医学院(郑州 450000)The First Clinical Medical College, Henan University of Traditional Chinese Medicine, Zhengzhou 450000, P. R. China
| | - 展 李
- 河南中医药大学 第一临床医学院(郑州 450000)The First Clinical Medical College, Henan University of Traditional Chinese Medicine, Zhengzhou 450000, P. R. China
| | - 继红 刘
- 河南中医药大学 第一临床医学院(郑州 450000)The First Clinical Medical College, Henan University of Traditional Chinese Medicine, Zhengzhou 450000, P. R. China
| | - 菲 谢
- 河南中医药大学 第一临床医学院(郑州 450000)The First Clinical Medical College, Henan University of Traditional Chinese Medicine, Zhengzhou 450000, P. R. China
- 中国人民解放军总医院第一医学中心 呼吸与危重症医学科(北京 100091)Department of Respiratory and Critical Care Medicine, The First Medical Center of Chinese PLA General Hospital, Beijing 100091, P. R. China
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Gremme Y, Derlien S, Katzer K, Reuken PA, Stallmach A, Lewejohann JC, Lemhöfer C. Visualizing exertional dyspnea in a post-COVID patient using electrical impedance tomography. Infection 2023; 51:1841-1845. [PMID: 37322387 PMCID: PMC10665229 DOI: 10.1007/s15010-023-02062-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 06/08/2023] [Indexed: 06/17/2023]
Abstract
PURPOSE AND METHOD Many post-COVID patients suffer from dyspnea on exertion. To visualize exercise-induced dyspnea, a post-COVID patient and a healthy volunteer underwent an exercise test on a treadmill under stress relevant to everyday life monitored by electrical impedance tomography (EIT). RESULTS The lung-healthy volunteer showed an even ventilation distribution throughout the assessment, a large ventilated area, and a butterfly-like lung shape with a convex lung rim. The post-COVID patient showed clear differences in the ventilated area compared to the control subject. During exercise, a constantly changing picture of differently ventilated areas is shown. However, especially the anterior regions were under-ventilated and larger areas were partially absent from ventilation. Overall, uncoordinated breathing and an uneven distribution of ventilation dominated the findings. CONCLUSION EIT is suitable for visualizing disturbed ventilation of the lungs, both at rest and under stress. The potential as a diagnostic tool in dyspnea assessment should be investigated.
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Affiliation(s)
- Yvonne Gremme
- Department of Internal Medicine IV (Gastroenterology, Hepatology and Infectious Diseases), Jena University Hospital/Friedrich-Schiller-Universität Jena, Jena, Germany.
| | - Steffen Derlien
- Institute of Physical and Rehabilitation Medicine, Jena University Hospital/Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Katrin Katzer
- Department of Internal Medicine IV (Gastroenterology, Hepatology and Infectious Diseases), Jena University Hospital/Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Philipp A Reuken
- Department of Internal Medicine IV (Gastroenterology, Hepatology and Infectious Diseases), Jena University Hospital/Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Andreas Stallmach
- Department of Internal Medicine IV (Gastroenterology, Hepatology and Infectious Diseases), Jena University Hospital/Friedrich-Schiller-Universität Jena, Jena, Germany
- Center for Sepsis Control and Care (CSCC), Jena University Hospital/Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Jan-Christoph Lewejohann
- Department of Emergency Medicine, Jena University Hospital/Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Christina Lemhöfer
- Institute of Physical and Rehabilitation Medicine, Jena University Hospital/Friedrich-Schiller-Universität Jena, Jena, Germany
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Yuan X, Zhao Z, Chao Y, Chen D, Chen H, Zhang R, Liu S, Xie J, Yang Y, Qiu H, Heunks L, Liu L. Effects of early versus delayed application of prone position on ventilation-perfusion mismatch in patients with acute respiratory distress syndrome: a prospective observational study. Crit Care 2023; 27:462. [PMID: 38012731 PMCID: PMC10683149 DOI: 10.1186/s13054-023-04749-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 11/18/2023] [Indexed: 11/29/2023] Open
Abstract
BACKGROUND Prone position has been shown to improve oxygenation and survival in patients with early acute respiratory distress syndrome (ARDS). These beneficial effects are partly mediated by improved ventilation/perfusion (V/Q) distribution. Few studies have investigated the impact of early versus delayed proning on V/Q distribution in patients with ARDS. The aim of this study was to assess the regional ventilation and perfusion distribution in early versus persistent ARDS after prone position. METHODS This is a prospective, observational study from June 30, 2021, to October 1, 2022 at the medical ICU in Zhongda Hospital, Southeast University. Fifty-seven consecutive adult patients with moderate-to-severe ARDS ventilated in supine and prone position. Electrical impedance tomography was used to study V/Q distribution in the supine position and 12 h after a prone session. RESULTS Of the 57 patients, 33 were early ARDS (≤ 7 days) and 24 were persistent ARDS (> 7 days). Oxygenation significantly improved after proning in early ARDS (157 [121, 191] vs. 190 [164, 245] mm Hg, p < 0.001), whereas no significant change was found in persistent ARDS patients (168 [136, 232] vs.177 [155, 232] mm Hg, p = 0.10). Compared to supine position, prone reduced V/Q mismatch in early ARDS (28.7 [24.6, 35.4] vs. 22.8 [20.0, 26.8] %, p < 0.001), but increased V/Q mismatch in persistent ARDS (23.8 [19.8, 28.6] vs. 30.3 [24.5, 33.3] %, p = 0.006). In early ARDS, proning significantly reduced shunt in the dorsal region and dead space in the ventral region. In persistent ARDS, proning increased global shunt. A significant correlation was found between duration of ARDS onset to proning and the change in V/Q distribution (r = 0.54, p < 0.001). CONCLUSIONS Prone position significantly reduced V/Q mismatch in patients with early ARDS, while it increased V/Q mismatch in persistent ARDS patients. Trial registration ClinicalTrials.gov (NCT05207267, principal investigator Ling Liu, date of registration 2021.08.20).
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Affiliation(s)
- Xueyan Yuan
- Jiangsu Provincial Key Laboratory of Critical Care Medicine and Department of Critical Care Medicine, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, 210009, Jiangsu, China
| | - Zhanqi Zhao
- School of Biomedical Engineering, Guangzhou Medical University, Guangzhou, China
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
| | - Yali Chao
- Jiangsu Provincial Key Laboratory of Critical Care Medicine and Department of Critical Care Medicine, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, 210009, Jiangsu, China
| | - Dongyu Chen
- Jiangsu Provincial Key Laboratory of Critical Care Medicine and Department of Critical Care Medicine, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, 210009, Jiangsu, China
| | - Hui Chen
- Jiangsu Provincial Key Laboratory of Critical Care Medicine and Department of Critical Care Medicine, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, 210009, Jiangsu, China
| | - Rui Zhang
- Jiangsu Provincial Key Laboratory of Critical Care Medicine and Department of Critical Care Medicine, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, 210009, Jiangsu, China
| | - Songqiao Liu
- Jiangsu Provincial Key Laboratory of Critical Care Medicine and Department of Critical Care Medicine, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, 210009, Jiangsu, China
- Nanjing Lishui People's Hospital, Zhongda Hospital Lishui Branch, Southeast University, No. 86 Chongwen Road, Lishui District, Nanjing, 211200, Jiangsu, China
| | - Jianfeng Xie
- Jiangsu Provincial Key Laboratory of Critical Care Medicine and Department of Critical Care Medicine, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, 210009, Jiangsu, China
| | - Yi Yang
- Jiangsu Provincial Key Laboratory of Critical Care Medicine and Department of Critical Care Medicine, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, 210009, Jiangsu, China
| | - Haibo Qiu
- Jiangsu Provincial Key Laboratory of Critical Care Medicine and Department of Critical Care Medicine, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, 210009, Jiangsu, China
| | - Leo Heunks
- Department of Intensive Care, Erasmus University Medical Center, Rotterdam, The Netherlands
- Department of Intensive Care, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ling Liu
- Jiangsu Provincial Key Laboratory of Critical Care Medicine and Department of Critical Care Medicine, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, 210009, Jiangsu, China.
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Yue C, He H, Su L, Wang J, Yuan S, Long Y, Zhao Z. A novel method for diaphragm-based electrode belt position of electrical impedance tomography by ultrasound. J Intensive Care 2023; 11:41. [PMID: 37749637 PMCID: PMC10518967 DOI: 10.1186/s40560-023-00691-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 09/14/2023] [Indexed: 09/27/2023] Open
Abstract
BACKGROUND This aim of study was to introduce a diaphragm-based EIT-belt placement method based on diaphragm position by ultrasound, and to evaluate the difference between diaphragm-based EIT-belt placement and conventional EIT-belt placement. METHOD The diaphragm position (L0) determined by ultrasound was taken as zero reference level. The direction of headward is defined as positive, and toward feet is negative. For EIT data collection, the electrode belt was placed at 7 different levels, respectively (denoted as L-2 cm, L0, L2cm, L4cm, L6cm, L8cm, L10cm) at supine position in healthy volunteers. The diaphragm-based EIT-belt level (Lxcm) was defined where highest tidal impedance variation (TV) was achieved. Subsequently, EIT measurements were conducted at diaphragm-based EIT-belt levels and traditional EIT-belt level in 50 critically ill patients under mechanical ventilation. RESULT The highest TV was achieved at L6cm and the smallest at L-2 cm., so the L6cm were taken as diaphragm-based EIT-belt level by ultrasound in 8 healthy volunteers. In 23 patients, the diaphragm-based EIT-belt plane agreed with the conventional planes (4th-6th ICS), which was defined as the Agreed group. Other patients were classified to the Disagreed group (above 4th ICS). The Disagreed group has a significantly higher BMI and lower global TV at the diaphragm-based EIT-belt plane compared to the Agreed group. CONCLUSIONS The diaphragm-based EIT-belt position by ultrasound was feasible and resulted in different belt positions compared to the conventional position in > 50% of the examined subjects, especially in patients with higher BMI. Further study is required to validate the impact on EIT images with this novel method on clinical management.
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Affiliation(s)
- Chaofu Yue
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital,Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
- Department of Intensive Care Unit, QuJing No.1 Hospital, QuJing, Yun Nan, China
| | - Huaiwu He
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital,Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
| | - Longxiang Su
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital,Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Jun Wang
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital,Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
- Department of Intensive Care Unit, Shiyan People's Hospital of Bao'an District, Shenzhen, Guangdong, China
| | - Siyi Yuan
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital,Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Yun Long
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital,Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
| | - Zhanqi Zhao
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital,Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
- Institute of Technical Medicine, Furtwangen University, VS-Schwenningen, Germany.
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Yang L, Gao Z, Cao X, Fu F, Möller K, Frerichs I, Dai M, Zhao Z. The influence of gravity on electrical impedance tomography measurements during upper body position change. Heliyon 2023; 9:e15910. [PMID: 37215814 PMCID: PMC10192413 DOI: 10.1016/j.heliyon.2023.e15910] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 04/19/2023] [Accepted: 04/26/2023] [Indexed: 05/24/2023] Open
Abstract
Objective The aim of the study was to examine the influence of gravity on regional ventilation measured by electrical impedance tomography (EIT) with the standard electrode belt position at the 5th intercostal space during tilting from supine to sitting positions. Methods A total of 30 healthy volunteers were examined prospectively in supine position during quiet tidal breathing. Subsequently, the bed was tilted so that the upper body of the subjects achieved 30, 60 and 90° every 3 min. Regional ventilation distribution and end-expiratory lung impedance (EELI) were monitored with EIT throughout the whole experiment. Absolute tidal volumes were measured with spirometry and the volume-impedance ratio was calculated for each position. Results The volume-impedance ratio did not differ statistically between the studied body positions but 11 subjects exhibited a large change in ratio at one of the positions (outside 99.3% coverage). In general, ventilation distribution became more heterogeneous and moved towards dorsal regions as the upper body was tilted to 90-degree position. EELI increased and tidal volume decreased. The lung regions identified at various positions differed significantly. Conclusion Gravity has non-negligible influence on EIT data, as the upper body tilted from supine to sitting positions. The standard electrode belt position might be reconsidered if ventilation distribution is to be compared between supine and sitting positions.
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Affiliation(s)
- Lin Yang
- Department of Aerospace Medicine, Fourth Military Medical University, Xi'an, China
| | - Zhijun Gao
- Department of Aerospace Medicine, Fourth Military Medical University, Xi'an, China
| | - Xinsheng Cao
- Department of Aerospace Medicine, Fourth Military Medical University, Xi'an, China
| | - Feng Fu
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Knut Möller
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
| | - Inéz Frerichs
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre of Schleswig-Holstein Campus Kiel, Germany
| | - Meng Dai
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Zhanqi Zhao
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
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11
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Li Q, Li Y, Niu G, Li M, Deng J, Möller K, Frerichs I, Xi J, Jiang H, Zhao Z. Chest physiotherapy guided by electrical impedance tomography in high-dependency unit patients with pulmonary diseases: an introduction of methodology and feasibility. Crit Care 2023; 27:24. [PMID: 36650565 PMCID: PMC9847064 DOI: 10.1186/s13054-023-04308-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 01/07/2023] [Indexed: 01/19/2023] Open
Affiliation(s)
- Qing Li
- grid.24696.3f0000 0004 0369 153XDepartment of Pulmonary and Critical Care Medicine, Beijing Rehabilitation Hospital, Capital Medical University, Badachu Road, Shijingshan District, 100144 Beijing, China
| | - Yi Li
- grid.24696.3f0000 0004 0369 153XDepartment of Pulmonary and Critical Care Medicine, Beijing Rehabilitation Hospital, Capital Medical University, Badachu Road, Shijingshan District, 100144 Beijing, China
| | - Guangyu Niu
- grid.24696.3f0000 0004 0369 153XDepartment of Pulmonary and Critical Care Medicine, Beijing Rehabilitation Hospital, Capital Medical University, Badachu Road, Shijingshan District, 100144 Beijing, China
| | - Mingna Li
- grid.24696.3f0000 0004 0369 153XDepartment of Pulmonary and Critical Care Medicine, Beijing Rehabilitation Hospital, Capital Medical University, Badachu Road, Shijingshan District, 100144 Beijing, China
| | - Jia Deng
- grid.24696.3f0000 0004 0369 153XDepartment of Pulmonary and Critical Care Medicine, Beijing Rehabilitation Hospital, Capital Medical University, Badachu Road, Shijingshan District, 100144 Beijing, China
| | - Knut Möller
- grid.21051.370000 0001 0601 6589Institute of Technical Medicine, Furtwangen University, Jakob-Kienzle-Strasse 17, 78054 Villingen-Schwenningen, Germany
| | - Inéz Frerichs
- grid.412468.d0000 0004 0646 2097Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre of Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - Jianing Xi
- grid.24696.3f0000 0004 0369 153XDepartment of Pulmonary and Critical Care Medicine, Beijing Rehabilitation Hospital, Capital Medical University, Badachu Road, Shijingshan District, 100144 Beijing, China
| | - Hongying Jiang
- grid.24696.3f0000 0004 0369 153XDepartment of Pulmonary and Critical Care Medicine, Beijing Rehabilitation Hospital, Capital Medical University, Badachu Road, Shijingshan District, 100144 Beijing, China
| | - Zhanqi Zhao
- grid.21051.370000 0001 0601 6589Institute of Technical Medicine, Furtwangen University, Jakob-Kienzle-Strasse 17, 78054 Villingen-Schwenningen, Germany
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12
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Emerging trends and hot spots on electrical impedance tomography extrapulmonary applications. Heliyon 2022; 8:e12458. [PMID: 36619470 PMCID: PMC9812712 DOI: 10.1016/j.heliyon.2022.e12458] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 10/17/2022] [Accepted: 12/13/2022] [Indexed: 01/04/2023] Open
Abstract
Objective Electrical impedance tomography (EIT) develops rapidly in technology and applications. Nowadays EIT is used in multiple clinical and experimental scenarios including pulmonary, brain, and tissue monitoring, etc. The present study explores the research trends and hotspots on EIT extrapulmonary application research by bibliometrics analysis. Approach Publications on EIT extrapulmonary applications between 1987 and 2021 were retrieved from the Web of Science Core Collection database. For precise screening, search strategy "electrical impedance tomography" plus "hemodynamic" or "brain" or "nerve" or "cancer" or "venous" or "vessel" or "tumor" or "veterinary" or "tissue" or "cell" or "wearable" or "application" and excluding "lung", "ventilation" "respiratory", "pulmonary", "algorithm", "current", "voltage" or "electrode" were used. CiteSpace and VOSviewer were used to analyze the publication features, collaboration, keywords co-occurrence, and co-cited reference. Main results A total of 506 articles were finally identified. The global publication numbers on extrapulmonary applications gradually increased yearly in the past 30 years. The US, UK, and China contributed most three publications concerning EIT extrapulmonary applications. "tissues", "conductivity", "model" were research hotspots, and "cutaneous melanoma", "microstructure", "diagnosis" were recent topics (Portions of this research have previously been presented in poster form). Significance Overall, EIT extrapulmonary applications bibliometrics analysis provides a unique insight into research focus, current trends, and future directions.
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13
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Lin Z, Huang W, Gao Z, Yang L, Li Y, Lu Y, Dai M, Fu F, Sang L, Zhao Z. The influence of reference electrode in electrical impedance tomography. Heliyon 2022; 8:e12454. [PMID: 36590551 PMCID: PMC9800185 DOI: 10.1016/j.heliyon.2022.e12454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 09/26/2022] [Accepted: 12/12/2022] [Indexed: 12/26/2022] Open
Abstract
Background Some electrical impedance tomography (EIT) devices equip reference electrodes. In practice, it is not uncommon to observe high contact impedance for the reference electrode. The influence of bad contact reference electrode on data quality is unknown. The study aimed to investigate the influence of reference electrode on EIT image reconstruction. Methods Thirty lung healthy volunteers were prospectively examined with EIT. The subjects were spontaneously breathing in supine position. Three scenarios were constructed: 1. Normal measurement; 2. Reference electrode disconnected without recalibration; 3. Reference electrode disconnected, and the measurement restarted after recalibration of the system. EIT-based parameters measuring spatial and temporal ventilation distributions were calculated and compared. A so-call deviation score was calculated to assess the differences in EIT parameters between scenarios 2 and 1, between 3 and 1. Results The absolute differences for all parameters were significantly higher than zero (p < 0.01 for all parameters and scenarios). Deviation score for scenario 2 was 4.5 ± 3.5. Four subjects had a deviation score of 0 in scenario 2 and five subjects had a score of 1. The deviation in scenario 3 was higher (6.1 ± 3.1). No subjects had a score of 0 and only two subjects had a score of 1. Conclusions For EIT systems that equips with reference electrode, it is important to ensure the proper contact and functionality of the reference electrode. The EIT data quality would remain unchanged in only a small portion of subjects.
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Affiliation(s)
- Zhimin Lin
- State Key Lab of Respiratory Diseases, Guangzhou Institute of Respiratory Health, Guangzhou Medical University, The First Affiliated Hospital of Guangzhou Medical University, Department of Critical Care Medicine, Guangzhou, China
| | - Weixiang Huang
- State Key Lab of Respiratory Diseases, Guangzhou Institute of Respiratory Health, Guangzhou Medical University, The First Affiliated Hospital of Guangzhou Medical University, Department of Critical Care Medicine, Guangzhou, China
| | - Zhijun Gao
- Department of Aerospace Medicine, Air Force Medical University, Xi'an, China
| | - Lin Yang
- Department of Aerospace Medicine, Air Force Medical University, Xi'an, China,Corresponding author.
| | - Yimin Li
- State Key Lab of Respiratory Diseases, Guangzhou Institute of Respiratory Health, Guangzhou Medical University, The First Affiliated Hospital of Guangzhou Medical University, Department of Critical Care Medicine, Guangzhou, China
| | - Yu Lu
- Herz Medical, Suzhou, China
| | - Meng Dai
- Department of Biomedical Engineering, Air Force Medical University, Xi'an, China
| | - Feng Fu
- Department of Biomedical Engineering, Air Force Medical University, Xi'an, China
| | - Ling Sang
- State Key Lab of Respiratory Diseases, Guangzhou Institute of Respiratory Health, Guangzhou Medical University, The First Affiliated Hospital of Guangzhou Medical University, Department of Critical Care Medicine, Guangzhou, China,Guangzhou Laboratory, Guangzhou, China,Corresponding author.
| | - Zhanqi Zhao
- Department of Biomedical Engineering, Air Force Medical University, Xi'an, China,Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
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14
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Liu W, Ding X, He H, Long Y, Cui N. Screening for the causes of refractory hypoxemia in critically ill patients: A case report. Front Med (Lausanne) 2022; 9:1065319. [PMID: 36579151 PMCID: PMC9790913 DOI: 10.3389/fmed.2022.1065319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Accepted: 11/28/2022] [Indexed: 12/14/2022] Open
Abstract
Hypoxemia was a very common symptom in critical patients and should be treated immediately before resulting in permanent organ failure. Rapid diagnosis of the etiology of hypoxemia could be achieved by combining the use of various bedside and radiation-free techniques such as lung ultrasound, electrical impedance tomography and echocardiography. By presenting a case of serious acute refractory hypoxemia, we proposed an efficient protocol for diagnosing and treating hypoxemia in a safe and fast way.
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15
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Wang N, He H, Long Y, Liu D, Wang Q, Jiang J, Xue Y, Yuan S, Chi Y, Zhao Z. Two regional ventilation–perfusion patterns of lung consolidation assessed by electrical impedance tomography and ultrasound. Crit Care 2022; 26:357. [PMID: 36397063 PMCID: PMC9669526 DOI: 10.1186/s13054-022-04235-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 11/10/2022] [Indexed: 11/19/2022] Open
Affiliation(s)
- Na Wang
- grid.506261.60000 0001 0706 7839Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, 1 Shuaifuyuan, Dongcheng District, Beijing, China
| | - Huaiwu He
- grid.506261.60000 0001 0706 7839Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, 1 Shuaifuyuan, Dongcheng District, Beijing, China
| | - Yun Long
- grid.506261.60000 0001 0706 7839Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, 1 Shuaifuyuan, Dongcheng District, Beijing, China
| | - Dawei Liu
- grid.506261.60000 0001 0706 7839Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, 1 Shuaifuyuan, Dongcheng District, Beijing, China
| | - Qianling Wang
- grid.506261.60000 0001 0706 7839Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, 1 Shuaifuyuan, Dongcheng District, Beijing, China
| | - Jing Jiang
- grid.506261.60000 0001 0706 7839Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, 1 Shuaifuyuan, Dongcheng District, Beijing, China ,Department of Critical Care Medicine, Chongqing General Hospital, No. 118, Xingguang Avenue, Liangjiang New Area, Chongqing, 401147 China
| | - Yuechuan Xue
- grid.506261.60000 0001 0706 7839Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, 1 Shuaifuyuan, Dongcheng District, Beijing, China
| | - Siyi Yuan
- grid.506261.60000 0001 0706 7839Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, 1 Shuaifuyuan, Dongcheng District, Beijing, China
| | - Yi Chi
- grid.506261.60000 0001 0706 7839Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, 1 Shuaifuyuan, Dongcheng District, Beijing, China
| | - Zhanqi Zhao
- grid.233520.50000 0004 1761 4404Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China ,grid.21051.370000 0001 0601 6589Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
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16
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Yang Y, He H, Long Y, Chi Y, Yuan S, Shen Z, Frerichs I, Zhao Z. Bedside electrical impedance tomography in early diagnosis of pneumothorax in mechanically ventilated ICU patients — a single-center retrospective cohort study. J Clin Monit Comput 2022; 37:629-637. [PMID: 36333577 DOI: 10.1007/s10877-022-00935-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Accepted: 10/15/2022] [Indexed: 11/06/2022]
Abstract
PURPOSE This study aimed to evaluate the routine use of electrical impedance tomography (EIT) to diagnose pneumothorax (PTX) in mechanically ventilated patients in the intensive care unit (ICU). METHODS A retrospective cohort study was conducted including mechanically ventilated supine patients who received EIT examinations. The EIT-based tidal variation was divided into ventral and dorsal regions of interest (ROIs): upper right (UR, ROI1), upper left (UL, ROI2) lower right (LR, ROI3), and lower left (LL, ROI4), and the ventilation defect score (DS) was calculated in each quadrant. Furthermore, horizontal ventral ventilation index (HVVI) was defined as ROI1% / ROI2% in the two ventral quadrants if ROI1% > ROI2%, otherwise HVVI = ROI2% / ROI1%. RESULTS A total of 203 patients were included, 25 of them with confirmed PTX. In the PTX patients, preceding cardiac surgery was the most common cause of PTX. Compared with the patients without PTX, the PTX patients had a higher DS in the ventral quadrants [median and interquartile range (IQR): 1.00 (0.00, 2.00) vs. 0.00 (0.00, 0.00), P < 0.001] respectively, but similar in the dorsal quadrants [median and IQR: 1.00 (0.00, 1.00) vs. 0.00 (0.00, 1.00), P = 0.722]. Moreover, a higher HVVI was found in the PTX group [median and IQR: 2.51 (1.58, 3.52) vs. 1.36 (1.15, 1.77), P < 0.001]. The area under the receiver operating characteristic curve of the HVVI to differentiate PTX from non-PTX was 0.88, with a sensitivity of 70% and a specificity of 90% when the cut-off value was 2.57. CONCLUSION The ventilation defect in the ventral regions and a high HVVI on EIT were observed in mechanically ventilated patients with PTX, which should trigger further diagnostics to confirm it.
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Affiliation(s)
- Yingying Yang
- State Key Laboratory of Complex Severe and Rare Disease, Department of Critical Care Medicine, Peking Union Medical College, Peking Union Medical College Hospital, 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, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
| | - Yun Long
- State Key Laboratory of Complex Severe and Rare Disease, Department of Critical Care Medicine, Peking Union Medical College, Peking Union Medical College Hospital, 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, Peking Union Medical College Hospital, 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, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Zhoutian Shen
- Institute for Health Informatics, University of Minnesota, Minneapolis, MN, USA
| | - 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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17
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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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18
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He H, Jiang J, Xu M, Yuan S, Long Y, Chi Y, Frerichs I, Zhao Z. Saline bolus-based electrical impedance tomography method for rapid bedside assessment of regional lung perfusion during ECMO therapy. Crit Care 2022; 26:266. [PMID: 36064724 PMCID: PMC9443643 DOI: 10.1186/s13054-022-04142-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Accepted: 08/09/2022] [Indexed: 11/10/2022] Open
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19
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Yang L, Fu F, Frerichs I, Moeller K, Dai M, Zhao Z. The calculation of electrical impedance tomography based silent spaces requires individual thorax and lung contours. Physiol Meas 2022; 43. [PMID: 35995039 DOI: 10.1088/1361-6579/ac8bc2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 08/22/2022] [Indexed: 11/12/2022]
Abstract
OBJECTIVE The present study evaluates the influence of different thorax contours (generic vs individual) on the parameter "silent spaces" computed from electrical impedance tomography (EIT) measurements. APPROACH Six patients with acute respiratory distress syndrome were analyzed retrospectively. EIT measurements were performed and the silent spaces were calculated based on (1) patient-specific contours Sind, (2) generic adult male contours SEidorsA and (3) generic neonate contours SEidorsN. MAIN RESULTS The differences among all studied subjects were 5±6% and 8±7% for Sind vs. SEidorsA, Sind vs. SEidorsN, respectively (median ± interquartile range). Sind values were higher than the generic ones in two patients. SIGNIFICANCE In the present study, we demonstrated the differences in values when the silent spaces were calculated based on different body and organ contours. To our knowledge, this study was the first one showing explicitly that silent spaces calculated with generic thorax and lung contours might lead to results with different locations and values as compared to the calculation with subject-specific models. Interpretations of silent spaces should be proceeded with caution.
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Affiliation(s)
- Lin Yang
- Fourth Military Medical University, Xi'an, Xi'an, 710032, CHINA
| | - Feng Fu
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, Xi'an, 710000, CHINA
| | - Inez Frerichs
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein Campus Kiel, Kiel, Kiel, x, GERMANY
| | - Knut Moeller
- Institute of Technical Medicine, Furtwangen University, Jakob-Kienzle-Strasse 17, Villingen-Schwenningen, D-78054, GERMANY
| | - Meng Dai
- Biomedical Engineering Department, Fourth Military Medical University, 17 Changlex West Road, Xian, Shaanxi 710033, PR CHINA, Xi'an, 710000, CHINA
| | - Zhanqi Zhao
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, Xi'an, 710032, CHINA
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20
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He H, Long Y, Möller K, Zhao Z. Editorial: Bedside visual image technologies for respiratory and circulatory management in intensive care settings. Front Med (Lausanne) 2022; 9:973679. [PMID: 35924036 PMCID: PMC9340248 DOI: 10.3389/fmed.2022.973679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 07/04/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
- 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
- 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
| | - Knut Möller
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
| | - Zhanqi Zhao
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
- Zhanqi Zhao
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21
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Ball L, Scaramuzzo G, Herrmann J, Cereda M. Lung aeration, ventilation, and perfusion imaging. Curr Opin Crit Care 2022; 28:302-307. [PMID: 35653251 PMCID: PMC9178949 DOI: 10.1097/mcc.0000000000000942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
PURPOSE OF REVIEW Lung imaging is a cornerstone of the management of patients admitted to the intensive care unit (ICU), providing anatomical and functional information on the respiratory system function. The aim of this review is to provide an overview of mechanisms and applications of conventional and emerging lung imaging techniques in critically ill patients. RECENT FINDINGS Chest radiographs provide information on lung structure and have several limitations in the ICU setting; however, scoring systems can be used to stratify patient severity and predict clinical outcomes. Computed tomography (CT) is the gold standard for assessment of lung aeration but requires moving the patients to the CT facility. Dual-energy CT has been recently applied to simultaneous study of lung aeration and perfusion in patients with respiratory failure. Lung ultrasound has an established role in the routine bedside assessment of ICU patients, but has poor spatial resolution and largely relies on the analysis of artifacts. Electrical impedance tomography is an emerging technique capable of depicting ventilation and perfusion at the bedside and at the regional level. SUMMARY Clinicians should be confident with the technical aspects, indications, and limitations of each lung imaging technique to improve patient care.
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Affiliation(s)
- Lorenzo Ball
- Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa, Genoa, Italy
- Anesthesia and Intensive Care, Ospedale Policlinico San Martino, IRCCS per l’Oncologia e le Neuroscienze, Genoa, Italy
| | - Gaetano Scaramuzzo
- Department of Translational medicine, University of Ferrara, Ferrara, Italy
- Anesthesia and intensive care, Arcispedale Sant’Anna, Ferrara, Italy
| | - Jake Herrmann
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, United States of America
| | - Maurizio Cereda
- Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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22
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Chi Y, Zhao Z, Frerichs I, Long Y, He H. Prevalence and prognosis of respiratory pendelluft phenomenon in mechanically ventilated ICU patients with acute respiratory failure: a retrospective cohort study. Ann Intensive Care 2022; 12:22. [PMID: 35246748 PMCID: PMC8897528 DOI: 10.1186/s13613-022-00995-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 02/11/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Respiratory pendelluft phenomenon, defined as intrapulmonary gas redistribution caused by asynchronous alveolar ventilation, could be potentially harmful by inducing lung injury. The aim of the present study was to investigate its prevalence and prognosis in intensive care unit (ICU) patients with acute respiratory failure (ARF). METHODS This was a retrospective observational study on 200 mechanically ventilated ARF patients treated in a tertiary ICU. The presence of pendelluft was determined using electrical impedance tomography (EIT) within 48 h after admission. Its amplitude was defined as the impedance difference between the sum of all regional tidal impedance variation and the global tidal impedance variation. A value above 2.5% (the 95th percentile from 30 healthy volunteers) was considered confirmative for its occurrence. RESULTS Pendelluft was found in 61 patients (39 in 94 patients with spontaneous breathing, 22 in 106 receiving controlled ventilation), with an overall prevalence of 31%. Existence of spontaneous breathing and higher global inhomogeneity index were associated with pendelluft. Patients with pendelluft had a longer ICU length of stay [10 (6, 14) vs. 7 (4, 11) days; median (lower, upper quartile); p = 0.022] and shorter 14-day ventilator-free days [8 (1, 10) vs. 10 (6, 12) days; p = 0.015]. Subgroup survival analysis suggested the association between pendelluft and longer ventilation duration, which was significant only in patients with PaO2/FiO2 ratio below 200 mmHg (log-rank p = 0.042). ICU mortality did not differ between the patients with and without pendelluft. CONCLUSIONS Respiratory pendelluft occurred often in our study group and it was associated with longer ventilation duration. Early recognition of this phenomenon should trigger interventions aimed at alleviating pendelluft.
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Affiliation(s)
- 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, 1 shuaifuyuan, Dongcheng District, Beijing, China
| | - Zhanqi Zhao
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China.,Institute of Technical Medicine, Furtwangen University, VS-Schwenningen, Germany
| | - Inéz Frerichs
- Department of Anesthesiology and Intensive Care Medicine, University Medical Center of Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - 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, 1 shuaifuyuan, Dongcheng District, 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, 1 shuaifuyuan, Dongcheng District, Beijing, China.
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23
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Li J, Zeng F, Yang F, Luo X, Liu R, Ren Y, Lan Y, Lei Y, Zhao G, Huang X. Electrical Impedance Tomography Predicts Weaning Success in Adult Patients With Delayed Upper Abdominal Surgery: A Single-Center Retrospective Study. Front Med (Lausanne) 2021; 8:748493. [PMID: 34926497 PMCID: PMC8674867 DOI: 10.3389/fmed.2021.748493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 11/09/2021] [Indexed: 11/13/2022] Open
Abstract
Objective: To evaluate the predictive value of electrical impedance tomography (EIT) in patients with delayed ventilator withdrawal after upper abdominal surgery. Methods: We retrospectively analyzed data of patients who were ventilated >24 h after upper abdominal surgery between January 2018 and August 2019. The patients were divided into successful (group S) and failed (group F) weaning groups. EIT recordings were obtained at 0, 5, 15, and 30 min of spontaneous breathing trials (SBTs) with SBT at 0 min set as baseline. We assessed the change in delta end-expiratory lung impedance and tidal volume ratio (ΔEELI/VT) from baseline, the change in compliance change percentage variation (|Δ(CW-CL)|) from baseline, the standard deviation of regional ventilation delay index (RVDSD), and global inhomogeneity (GI) using generalized estimation equation analyses. Receiver operating characteristic curve analyses were performed to evaluate the predictive value of parameters indicating weaning success. Results: Among the 32 included patients, ventilation weaning was successful in 23 patients but failed in nine. Generalized estimation equation analysis showed that compared with group F, the ΔEELI/VT was lower, and the GI, RVDSD, and (|Δ(CW-CL)|) were higher in group S. For predicting withdrawal failure, the areas under the curve of the ΔEELI/VT, (|Δ(CW-CL)|), and the RVDSD were 0.819, 0.918, and 0.918, and 0.816, 0.884, and 0.918 at 15 and 30 min during the SBTs, respectively. Conclusion: The electrical impedance tomography may predict the success rate of ventilator weaning in patients with delayed ventilator withdrawal after upper abdominal surgery.
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Affiliation(s)
- Jiajia Li
- Department of Intensive Care Unit, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Fan Zeng
- Department of Intensive Care Unit, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Fuxun Yang
- Department of Intensive Care Unit, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Xiaoxiu Luo
- Department of Intensive Care Unit, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Rongan Liu
- Department of Intensive Care Unit, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Yinjie Ren
- Department of Intensive Care Unit, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Yunping Lan
- Department of Intensive Care Unit, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Yu Lei
- Department of Intensive Care Unit, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Gaoping Zhao
- Department of Gastrointestinal Surgery, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Xiaobo Huang
- Department of Intensive Care Unit, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
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24
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Wang X, Zhao H, Cui N. The Role of Electrical Impedance Tomography for Management of High-Risk Pulmonary Embolism in a Postoperative Patient. Front Med (Lausanne) 2021; 8:773471. [PMID: 34869492 PMCID: PMC8639861 DOI: 10.3389/fmed.2021.773471] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 10/28/2021] [Indexed: 11/21/2022] Open
Abstract
Electrical impedance tomography (EIT) is a non-invasive, radiation-free and bedside imaging tool that is widely used for real-time monitoring of lung ventilation. Recently, it has been proposed for use in quantitative assessment of regional lung perfusion with hypertonic saline bolus injection and consequently for pulmonary embolism (PE) detection. Here, we present a case of high-risk PE in a postoperative patient, in which EIT monitoring provided us with useful information for diagnosis and decision-making, especially with the challenge of anticoagulation and risk of bleeding.
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Affiliation(s)
- Xinchen Wang
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Hua Zhao
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Na Cui
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
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25
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Xu M, He H, Long Y. Lung Perfusion Assessment by Bedside Electrical Impedance Tomography in Critically Ill Patients. Front Physiol 2021; 12:748724. [PMID: 34721072 PMCID: PMC8548642 DOI: 10.3389/fphys.2021.748724] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 09/13/2021] [Indexed: 12/02/2022] Open
Abstract
As a portable, radiation-free imaging modality, electrical impedance tomography (EIT) technology has shown promise in the bedside visual assessment of lung perfusion distribution in critically ill patients. The two main methods of EIT for assessing lung perfusion are the pulsatility and conductivity contrast (saline) bolus method. Increasing attention is being paid to the saline bolus EIT method in the evaluation of regional pulmonary perfusion in clinical practice. This study seeks to provide an overview of experimental and clinical studies with the aim of clarifying the progress made in the use of the saline bolus EIT method. Animal studies revealed that the saline bolus EIT method presented good consistency with single-photon emission CT (SPECT) in the evaluation of lung regional perfusion changes in various pathological conditions. Moreover, the saline bolus EIT method has been applied to assess the lung perfusion in a pulmonary embolism and the effect of positive end-expiratory pressure (PEEP) on regional ventilation/perfusion ratio (V/Q) and acute respiratory distress syndrome (ARDS) in several clinical studies. The implementation of saline boluses, data analyses, precision, and cutoff values varied among different studies, and a consensus must be reached regarding the clinical application of the saline bolus EIT method. Further study is required to validate the impact of the described saline bolus EIT method on decision-making, therapeutic management, and outcomes in critically ill patients.
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Affiliation(s)
- Mengru Xu
- State Key Laboratory of Complex Severe and Rare Diseases, Department of Critical Care Medicine, Peking Union Medical College, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Huaiwu He
- State Key Laboratory of Complex Severe and Rare Diseases, Department of Critical Care Medicine, Peking Union Medical College, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Yun Long
- State Key Laboratory of Complex Severe and Rare Diseases, Department of Critical Care Medicine, Peking Union Medical College, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
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