1
|
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.
Collapse
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
| |
Collapse
|
2
|
Ding C, Zhu Y, Zhang S, Zhao Z, Gao Y, Li Z. Bedside electrical impedance tomography to assist the management of pulmonary embolism: A case report. Heliyon 2024; 10:e25159. [PMID: 38322858 PMCID: PMC10844270 DOI: 10.1016/j.heliyon.2024.e25159] [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: 03/30/2023] [Revised: 01/05/2024] [Accepted: 01/22/2024] [Indexed: 02/08/2024] Open
Abstract
Background Pulmonary embolism (PE) is a common worldwide disease with high mortality. Timely diagnosis and management of PE could significantly improve clinical outcomes. Electrical impedance tomography (EIT) is a novel noninvasive technique to monitor lung perfusion and help detect PE at the bedside. Here we present a case of clinical management of subsegmental PE with the help of the bilateral ventilation and perfusion(V/Q) asymmetry EIT image. Case presentation A 72-year-old cancer patient with respiratory failure and acute kidney injury in the intensive care unit was suspected of PE based on his clinical manifestation. The contraindication of computed tomography pulmonary angiography (CTPA) for PE diagnosis prevented escalating anticoagulation therapy. Besides EIT ventilation and perfusion monitoring showed an abnormal asymmetry V/Q match between the bilateral lungs which promoted our decision to start systemic continuous anticoagulation therapy and improved the patient clinically. The following CTPA which clarified the diagnosis of PE suggests that the patient has benefited from our decision. Conclusion For critically ill patients with suspected PE, the asymmetry of the EIT V/Q image may provide crucial objective information for clinical management.
Collapse
Affiliation(s)
- Chenling Ding
- Department of Critical Care Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, China
| | - Yibo Zhu
- Department of Critical Care Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, China
| | - Shuyi Zhang
- Department of Critical Care Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, China
| | - Zhanqi Zhao
- School of Biomedical Engineering, Guangzhou Medical University, Guangzhou, China
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Beijing, China
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
| | - Yuan Gao
- Department of Critical Care Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, China
| | - Zhe Li
- Department of Critical Care Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, China
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Larrabee S, Nugen S, Bruhn A, Porter I, Stowe S, Adler A, Martin-Flores M, Araos J. Three-dimensional electrical impedance tomography to study regional ventilation/perfusion ratios in anesthetized pigs. Am J Physiol Lung Cell Mol Physiol 2023; 325:L638-L646. [PMID: 37724348 DOI: 10.1152/ajplung.00180.2023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 09/08/2023] [Accepted: 09/13/2023] [Indexed: 09/20/2023] Open
Abstract
This study aimed to develop a three-dimensional (3-D) method for assessing ventilation/perfusion (V/Q̇) ratios in a pig model of hemodynamic perturbations using electrical impedance tomography (EIT). To evaluate the physiological coherence of changes in EIT-derived V/Q̇ ratios, global EIT-derived V/Q̇ mismatches were compared with global gold standards. The study found regional heterogeneity in the distribution of V/Q̇ ratios in both the ventrodorsal and craniocaudal directions. Although global EIT-derived indices of V/Q̇ mismatch consistently underestimated both low and high V/Q̇ mismatch compared with global gold standards, the direction of the change was similar. We made the software available at no cost for other researchers to use. Future studies should compare regional V/Q̇ ratios determined by our method against other regional, high-resolution methods.NEW & NOTEWORTHY In this study, we introduce a novel 3-D method for assessing ventilation-perfusion (V/Q̇) ratios using electrical impedance tomography (EIT). Heterogeneity in V/Q̇ distribution showcases the significant potential for enhanced understanding of pulmonary conditions. This work signifies a substantial step forward in the application of EIT for monitoring and managing lung diseases.
Collapse
Affiliation(s)
- Shannon Larrabee
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States
| | - Sarah Nugen
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States
| | - Alejandro Bruhn
- Departamento de Medicina Intensiva, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Ian Porter
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States
| | - Symon Stowe
- Department of Systems and Computer Engineering, Carleton University, Ottawa, Ontario, Canada
| | - Andy Adler
- Department of Systems and Computer Engineering, Carleton University, Ottawa, Ontario, Canada
| | - Manuel Martin-Flores
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States
| | - Joaquin Araos
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States
| |
Collapse
|
5
|
Zhao Y, Su L, He H, Liu D, Long Y. Whole-process respiratory management strategies based on electrical impedance tomography in a pregnant woman with diffuse alveolar hemorrhage induced by systemic lupus erythematosus under veno-venous extracorporeal membrane oxygenation. Pulm Circ 2023; 13:e12302. [PMID: 37868717 PMCID: PMC10588315 DOI: 10.1002/pul2.12302] [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: 03/23/2023] [Revised: 09/20/2023] [Accepted: 10/15/2023] [Indexed: 10/24/2023] Open
Abstract
Electrical impedance tomography (EIT) as a bedside, noninvasive, radiation-free technology, could quantify alveolar collapse and over-distension and provide real-time ventilation images of lungs. Clinical studies have shown potential benefit in reducing lung injury by EIT to guide mechanical ventilation setting in acute respiratory distress syndrome (ARDS). The respiratory management of ARDS with venous-venous extracorporeal membrane oxygenation (VV ECMO) remains a challenge for ICU doctors. Moreover, EIT has gained great interests in the respiratory management in VV ECMO therapy. Here, EIT was used for respiratory management in the presented case of a 36-year-old gravida with systemic lupus erythematosus, who developed severe hypoxia caused by diffuse alveolar hemorrhage. Although the patient received mechanical ventilation, VV ECMO was further used for the refractory respiratory failure. EIT was applied to titrate positive end-expiratory pressure (PEEP), guide prone position and early mobilization, dynamic evaluating lung development during ECMO therapy. She was successfully rescued after comprehensive therapy. In summary, an EIT-guided whole-process respiratory management strategy that included PEEP titration, prone position, early mobilization, and dynamic lung ventilation monitoring was proposed. This case demonstrated that EIT-guided whole-process respiratory management strategy was feasible in the respiratory failure patient with VV ECMO therapy.
Collapse
Affiliation(s)
- Yu Zhao
- State Key Laboratory of Complex Severe and Rare Diseases, Department of Critical Care Medicine, Peking Union Medical College, Peking Union Medical College HospitalChinese Academy of Medical SciencesBeijingChina
| | - Longxiang Su
- State Key Laboratory of Complex Severe and Rare Diseases, Department of Critical Care Medicine, Peking Union Medical College, Peking Union Medical College HospitalChinese Academy of Medical SciencesBeijingChina
| | - Huaiwu He
- State Key Laboratory of Complex Severe and Rare Diseases, Department of Critical Care Medicine, Peking Union Medical College, Peking Union Medical College HospitalChinese Academy of Medical SciencesBeijingChina
| | - Dawei Liu
- State Key Laboratory of Complex Severe and Rare Diseases, Department of Critical Care Medicine, Peking Union Medical College, Peking Union Medical College HospitalChinese Academy of Medical SciencesBeijingChina
| | - Yun Long
- State Key Laboratory of Complex Severe and Rare Diseases, Department of Critical Care Medicine, Peking Union Medical College, Peking Union Medical College HospitalChinese Academy of Medical SciencesBeijingChina
| |
Collapse
|
6
|
Aggas JR, Abasi S, Ton C, Salehi S, Liu R, Brandacher G, Grayson WL, Guiseppi-Elie A. Real-Time Monitoring Using Multiplexed Multi-Electrode Bioelectrical Impedance Spectroscopy for the Stratification of Vascularized Composite Allografts: A Perspective on Predictive Analytics. Bioengineering (Basel) 2023; 10:bioengineering10040434. [PMID: 37106621 PMCID: PMC10135882 DOI: 10.3390/bioengineering10040434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 03/20/2023] [Accepted: 03/24/2023] [Indexed: 04/29/2023] Open
Abstract
Vascularized composite allotransplantation addresses injuries to complex anatomical structures such as the face, hand, and abdominal wall. Prolonged static cold storage of vascularized composite allografts (VCA) incurs damage and imposes transportation limits to their viability and availability. Tissue ischemia, the major clinical indication, is strongly correlated with negative transplantation outcomes. Machine perfusion and normothermia can extend preservation times. This perspective introduces multiplexed multi-electrode bioimpedance spectroscopy (MMBIS), an established bioanalytical method to quantify the interaction of the electrical current with tissue components, capable of measuring tissue edema, as a quantitative, noninvasive, real-time, continuous monitoring technique to provide crucially needed assessment of graft preservation efficacy and viability. MMBIS must be developed, and appropriate models explored to address the highly complex multi-tissue structures and time-temperature changes of VCA. Combined with artificial intelligence (AI), MMBIS can serve to stratify allografts for improvement in transplantation outcomes.
Collapse
Affiliation(s)
- John R Aggas
- Bioelectronics, Biosensors and Biochips (C3B®), Department of Biomedical Engineering, Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX 77843, USA
- Test Development, Roche Diagnostics, 9115 Hague Road, Indianapolis, IN 46256, USA
| | - Sara Abasi
- Bioelectronics, Biosensors and Biochips (C3B®), Department of Biomedical Engineering, Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX 77843, USA
- Media and Metabolism, Wildtype, Inc., 2325 3rd St., San Francisco, CA 94107, USA
| | - Carolyn Ton
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21231, USA
- Translational Tissue Engineering Center, Johns Hopkins University, Baltimore, MD 21231, USA
| | - Sara Salehi
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21231, USA
- Translational Tissue Engineering Center, Johns Hopkins University, Baltimore, MD 21231, USA
| | - Renee Liu
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21231, USA
- Translational Tissue Engineering Center, Johns Hopkins University, Baltimore, MD 21231, USA
| | - Gerald Brandacher
- Translational Tissue Engineering Center, Johns Hopkins University, Baltimore, MD 21231, USA
- Department of Plastic & Reconstructive Surgery, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Warren L Grayson
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21231, USA
- Translational Tissue Engineering Center, Johns Hopkins University, Baltimore, MD 21231, USA
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Anthony Guiseppi-Elie
- Bioelectronics, Biosensors and Biochips (C3B®), Department of Biomedical Engineering, Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX 77843, USA
- Department of Cardiovascular Sciences, Houston Methodist Institute for Academic Medicine and Houston Methodist Research Institute, 6670 Bertner Ave., Houston, TX 77030, USA
- ABTECH Scientific, Inc., Biotechnology Research Park, 800 East Leigh Street, Richmond, VA 23219, USA
| |
Collapse
|
7
|
Pan P, Li L, Xie F, Hu X, Guo Y, Xie L, Su L. Physiological Regulation of Pulmonary Microcirculation under Mechanical Ventilation at Different Cardiac Outputs and Positive End-Expiratory Pressures in a Porcine Model. J Pers Med 2023; 13:jpm13010107. [PMID: 36675768 PMCID: PMC9861575 DOI: 10.3390/jpm13010107] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 12/28/2022] [Accepted: 12/29/2022] [Indexed: 01/06/2023] Open
Abstract
This study was performed to visualize the hemodynamic effects of pulmonary microcirculation and ventilation/perfusion (V/Q) matching after mechanical ventilation under different cardiac outputs and positive end-expiratory pressures (PEEPs). Ten experimental pigs were randomly divided into high and low tidal volume groups, and ventilation/perfusion were measured by electrical impedance tomography (EIT) at different PEEPs. Then, all the pigs were redivided into high cardiac output (CO) and low CO groups and measured by EIT at different PEEP levels with a low tidal volume. Additionally, sidestream dark field (SDF) was used to measure pulmonary microcirculation. Hemodynamic parameters and respiratory mechanics parameters were recorded. As PEEP increased at high tidal volume, blood flow was impaired at a higher PEEP (20 cmH2O) compared with low tidal volume (shunt: 30.01 ± 0.69% vs. 17.95 ± 0.72%; V/Q ratio: 65.12 ± 1.97% vs. 76.57 ± 1.25%, p < 0.01). Low tidal volume combined with an appropriate PEEP is the best option from the match between ventilation and pulmonary blood flow. Increasing PEEP can solve the problem of excessive shunt at high CO, and the V/Q ratio tends to match. At low CO, the increased dead space can reach as high as 64.64 ± 7.13% when PEEP = 20 cmH2O. With increasing PEEP, the microcirculation index deteriorates, including total vessel density (TVD), proportion of perfused vessel (PPV), perfused vessel density (PVD), and microcirculatory flow index (MFI). The periodic collapse of pulmonary capillaries or interruption of blood flow obviously occurred with high PEEP. The hemodynamic parameters indicated that the transpulmonary capillary wall pressure (Pcap) of the low CO group was negative at PEEP = 5 cmH2O, which determines the opening and closing of the pulmonary microcirculation and controls lung perfusion and the production of extravascular lung water. Therefore, it is essential to couple macrocirculation and pulmonary microcirculation during mechanical ventilation by improving shunting and optimizing Pcap.
Collapse
Affiliation(s)
- Pan Pan
- College of Pulmonary and Critical Care Medicine Chinese PLA General Hospital, Beijing 100089, China
| | - Lina Li
- College of Pulmonary and Critical Care Medicine Chinese PLA General Hospital, Beijing 100089, China
| | - Fei Xie
- College of Pulmonary and Critical Care Medicine Chinese PLA General Hospital, Beijing 100089, China
| | - Xingshuo Hu
- College of Pulmonary and Critical Care Medicine Chinese PLA General Hospital, Beijing 100089, China
| | - Yinghua Guo
- College of Pulmonary and Critical Care Medicine Chinese PLA General Hospital, Beijing 100089, China
| | - Lixin Xie
- College of Pulmonary and Critical Care Medicine Chinese PLA General Hospital, Beijing 100089, China
- Correspondence: (L.X.); (L.S.)
| | - Longxiang Su
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, 1st Shuaifuyuan, Dongcheng District, Beijing 100730, China
- Correspondence: (L.X.); (L.S.)
| |
Collapse
|
8
|
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.
Collapse
|
9
|
Liu L, Xie J, Wang C, Zhao Z, Chong Y, Yuan X, Qiu H, Zhao M, Yang Y, Slutsky AS. Prone position improves lung ventilation–perfusion matching in non-intubated COVID-19 patients: a prospective physiologic study. Crit Care 2022; 26:193. [PMID: 35768877 PMCID: PMC9241304 DOI: 10.1186/s13054-022-04069-y] [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: 01/23/2022] [Accepted: 06/22/2022] [Indexed: 11/17/2022] Open
|
10
|
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.
Collapse
Affiliation(s)
| | | | - Xia Zheng
- *Correspondence: Xia Zheng, ; Qiang Fang,
| | - Qiang Fang
- *Correspondence: Xia Zheng, ; Qiang Fang,
| |
Collapse
|
11
|
Zhou R, He C, Chi Y, Yuan S, Tang B, Li Z, Li Q, He H, Long Y. Electrical impedance tomography to aid in the identification of hypoxemia etiology: Massive atelectasis or pneumothorax? A case report. Front Med (Lausanne) 2022; 9:970087. [PMID: 36117985 PMCID: PMC9481296 DOI: 10.3389/fmed.2022.970087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 08/18/2022] [Indexed: 11/24/2022] Open
Abstract
Background Bedside ultrasound is often used to determine the etiology of hypoxaemia, but not always with definitive results. This case reports the application of electrical impedance tomography (EIT) and saline injection to determine the etiology of hypoxaemia in a complex case that could not be identified by bedside ultrasound. The determination of the etiology of hypoxaemia by EIT and saline injection, regional ventilation and perfusion information can be used as a new clinical diagnostic method. Case presentation A post-cardiac surgery patient under prolonged mechanical ventilation for lung emphysema developed sudden hypoxemia in the intensive care unit (ICU). A line pattern and lung sliding sign abolishment were found in the left lung, but there was no evidence of a lung point sign on bedside ultrasound. Hence, the initial diagnosis was considered to be a massive pneumothorax. To further define the etiology, EIT and saline bolus were used to assess regional ventilation and perfusion. A massive ventilation defect was found in the left lung, in which regional perfusion was maintained, resulting in an intrapulmonary shunt in the left lung. Finally, the conjecture of a pneumothorax was ruled out considering the massive atelectasis. After the diagnosis was clarified, hypoxaemia was corrected by restorative ventilation of the left lung after changing the patient's posture and enhancing sputum drainage with chest physiotherapy. Conclusions This was the clinical case involving EIT and saline bolus to establish the differential diagnosis and guide clinical decisions for patients with acute hypoxemia. This study highlighted that combination regional ventilation, EIT perfusion, and saline bolus provided helpful information for determining the etiology of hypoxemia. The results of this study contribute to the development of emergency patient management.
Collapse
|
12
|
Kuk WJ, Wright NR. Bedside Diagnosis of Pulmonary Embolism Using Electrical Impedance Tomography: A Case Report. A A Pract 2022; 16:e01606. [DOI: 10.1213/xaa.0000000000001606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
13
|
Electrical impedance tomography in the adult intensive care unit. Curr Opin Crit Care 2022; 28:292-301. [DOI: 10.1097/mcc.0000000000000936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
14
|
Bayford R, Sadleir R, Frerichs I. Advances in electrical impedance tomography and bioimpedance including applications in COVID-19 diagnosis and treatment. Physiol Meas 2022; 43. [DOI: 10.1088/1361-6579/ac4e6c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 01/24/2022] [Indexed: 11/12/2022]
|
15
|
Zhao Z, Sang L, Oh TI. Editorial: CardioPulmonary Physiology: Novel Approaches to Pulmonary Function and Critical Care. Front Physiol 2022; 12:825098. [PMID: 35046843 PMCID: PMC8762205 DOI: 10.3389/fphys.2021.825098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 12/09/2021] [Indexed: 11/13/2022] Open
Affiliation(s)
- Zhanqi Zhao
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China.,Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
| | - Ling Sang
- State Key Lab of Respiratory Diseases, Guangzhou Laboratory, Department of Critical Care Medicine, Guangzhou Institute of Respiratory Health, Guangzhou Medical University, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Tong In Oh
- College of Medicine, Kyung Hee University, Seoul, South Korea
| |
Collapse
|
16
|
Nguyen DM, Duong Trong L, McEwan AL. An efficient and fast multi-band focused bioimpedance solution with EIT-based reconstruction for pulmonary embolism assessment: a simulation study from massive to segmental blockage. Physiol Meas 2022; 43. [PMID: 34986471 DOI: 10.1088/1361-6579/ac4830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 01/05/2022] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Pulmonary embolism (PE) is an acute condition that blocks the perfusion to the lungs and is a common complication of Covid-19. However, PE is often not diagnosed in time, especially in the pandemic time due to complicated diagnosis protocol. In this study, a non-invasive, fast and efficient bioimpedance method with the EIT-based reconstruction approach is proposed to assess the lung perfusion reliably. APPROACH Some proposals are presented to improve the sensitivity and accuracy for the bioimpedance method: (1) a new electrode configuration and focused pattern to help study deep changes caused by PE within each lung field separately, (2) a measurement strategy to compensate the effect of different boundary shapes and varied respiratory conditions on the perfusion signals and (3) an estimator to predict the lung perfusion capacity, from which the severity of PE can be assessed. The proposals were tested on the first-time simulation of PE events at different locations and degrees from segmental blockages to massive blockages. Different object boundary shapes and varied respiratory conditions were included in the simulation to represent for different populations in real measurements. RESULTS The correlation between the estimator and the perfusion was very promising (R = 0.91, errors < 6%). The measurement strategy with the proposed configuration and pattern has helped stabilize the estimator to non-perfusion factors such as the boundary shapes and varied respiration conditions (3-5% errors). SIGNIFICANCE This promising preliminary result has demonstrated the proposed bioimpedance method's capability and feasibility, and might start a new direction for this application.
Collapse
Affiliation(s)
- Duc Minh Nguyen
- School of Biomedical Engineering, University of Sydney - Camperdown and Darlington Campus SciTech Library, Room 415, Level 4, Link Building Faculty of Engineering and IT, The University of Sydney, Darlington, Hanoi, New South Wales, 100000, AUSTRALIA
| | - Luong Duong Trong
- School of Electronics and Telecommunication, Hanoi University of Science and Technology, No. 1, Dai Co Viet Street, Hai Ba Trung District, Hanoi, 100000, VIET NAM
| | - Alistair L McEwan
- School of Biomedical Engineering, The University of Sydney, Room 415, Level 4, Link Building Faculty of Engineering and IT, The University of Sydney, Darlington NSW 2006, Australia, Sydney, New South Wales, 2006, AUSTRALIA
| |
Collapse
|
17
|
Zhang C, Wang Y, Liu L, Li Q, Li Y, Li N, Xi J, Jiang H, Fu F, Frerichs I, Möller K, Zhao Z. Regional ventilation distribution in patients with scoliosis assessed by electrical impedance tomography: is individual thorax shape required? Respir Physiol Neurobiol 2022; 299:103854. [DOI: 10.1016/j.resp.2022.103854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 01/20/2022] [Accepted: 01/28/2022] [Indexed: 10/19/2022]
|
18
|
Evaluation of atelectasis using electrical impedance tomography during procedural deep sedation for MRI in small children: A prospective observational trial. J Clin Anesth 2021; 77:110626. [PMID: 34902800 DOI: 10.1016/j.jclinane.2021.110626] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 11/29/2021] [Accepted: 12/02/2021] [Indexed: 12/14/2022]
Abstract
STUDY OBJECTIVE To investigate the variation of poorly ventilated lung units (i.e., silent spaces) in children undergoing procedural sedation in a day-hospital setting, until discharge home from the Post-Anesthesia Care Unit (PACU). DESIGN Prospective, single-center, observational cohort trial. SETTING This study was conducted at the radiology department and in PACU at Bern University Hospital (Switzerland), a tertiary care hospital. PATIENTS We included 25 children (1-6 years, ASA I-III) scheduled for cerebral magnetic resonance imaging scan, spontaneously breathing under deep sedation. Children planned for tracheal intubation, supraglottic airway insertion, or with contraindication for propofol were excluded. INTERVENTION After intravenous or inhaled induction, deep sedation was performed with 10 mg/kg/h Propofol. All children received nasal oxygen 0.3 ml/kg/min. MEASUREMENTS The proportion of silent spaces and the global inhomogeneity index were determined at each of five procedural points, using electrical impedance tomography: before induction (T1); before (T2) and after (T3) magnetic resonance imaging; at the end of sedation before transport to the PACU (T4); and before hospital discharge (T5). MAIN RESULTS The median [interquartile range (IQR)] proportion of silent spaces at the five analysis points were: T1, 5% [2%-14%]; T2, 10% [7%-14%]; T3, 12% [5%-23%]; T4, 12% [7%-24%]; and T5, 3% [2%-11%]. These defined significant changes in silent spaces over the course of sedation (p = 0.009), but no differences in silent spaces from before induction to before discharge from the PACU (T1 vs. T5; p = 0.29). Median [IQR] global inhomogeneity indices were 0.57 [0.55-0.58], 0.56 [0.53-0.59], 0.56 [0.54-0.59], 0.57 [0.54-0.60] and 0.56 [0.54-0.57], respectively (p = 0.93). None of the children reported anesthesia-related complications. CONCLUSION Deep sedation results in significantly increased poorly ventilated lung units during sedation. However, this does not significantly affect ventilation homogeneity, which was fully resolved at discharge from the PACU. TRIAL REGISTRATION clinicaltrials.gov, identifier NCT04507581.
Collapse
|
19
|
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.
Collapse
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
| |
Collapse
|
20
|
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.
Collapse
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
| |
Collapse
|
21
|
He H, Chi Y, Long Y, Yuan S, Zhang R, Yang Y, Frerichs I, Möller K, Fu F, Zhao Z. Three broad classifications of acute respiratory failure etiologies based on regional ventilation and perfusion by electrical impedance tomography: a hypothesis-generating study. Ann Intensive Care 2021; 11:134. [PMID: 34453622 PMCID: PMC8401348 DOI: 10.1186/s13613-021-00921-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 08/19/2021] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND The aim of this study was to validate whether regional ventilation and perfusion data measured by electrical impedance tomography (EIT) with saline bolus could discriminate three broad acute respiratory failure (ARF) etiologies. METHODS Perfusion image was generated from EIT-based impedance-time curves caused by 10 ml 10% NaCl injection during a respiratory hold. Ventilation image was captured before the breath holding period under regular mechanical ventilation. DeadSpace%, Shunt% and VQMatch% were calculated based on lung perfusion and ventilation images. Ventilation and perfusion maps were divided into four cross-quadrants (lower left and right, upper left and right). Regional distribution defects of each quadrant were scored as 0 (distribution% ≥ 15%), 1 (15% > distribution% ≥ 10%) and 2 (distribution% < 10%). Data percentile distributions in the control group and clinical simplicity were taken into consideration when defining the scores. Overall defect scores (DefectV, DefectQ and DefectV+Q) were the sum of four cross-quadrants of the corresponding images. RESULTS A total of 108 ICU patients were prospectively included: 93 with ARF and 15 without as a control. PaO2/FiO2 was significantly correlated with VQMatch% (r = 0.324, P = 0.001). Three broad etiologies of ARF were identified based on clinical judgment: pulmonary embolism-related disease (PED, n = 14); diffuse lung involvement disease (DLD, n = 21) and focal lung involvement disease (FLD, n = 58). The PED group had a significantly higher DeadSpace% [40(24)% vs. 14(15)%, PED group vs. the rest of the subjects; median(interquartile range); P < 0.0001] and DefectQ score than the other groups [1(1) vs. 0(1), PED vs. the rest; P < 0.0001]. The DLD group had a significantly lower DefectV+Q score than the PED and FLD groups [0(1) vs. 2.5(2) vs. 3(3), DLD vs. PED vs. FLD; P < 0.0001]. The FLD group had a significantly higher DefectV score than the other groups [2(2) vs. 0(1), FLD vs. the rest; P < 0.0001]. The area under the receiver operating characteristic (AUC) for using DeadSpace% to identify PED was 0.894 in all ARF patients. The AUC for using the DefectV+Q score to identify DLD was 0.893. The AUC for using the DefectV score to identify FLD was 0.832. CONCLUSIONS Our study showed that it was feasible to characterize three broad etiologies of ARF with EIT-based regional ventilation and perfusion. Further study is required to validate clinical applicability of this method. Trial registration clinicaltrials, NCT04081142. Registered 9 September 2019-retrospectively registered, https://clinicaltrials.gov/show/NCT04081142 .
Collapse
Affiliation(s)
- 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
| | - Yi Chi
- 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.
| | - 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
| | - Rui Zhang
- 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
| | - Yingying Yang
- 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
| | - Inéz Frerichs
- Department of Anesthesiology and Intensive Care Medicine, University Medical Center of Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - Knut Möller
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
| | - Feng Fu
- Department of Biomedical Engineering, Fourth Military Medical University, 169 Changle Xi Rd, Xi'an, China
| | - Zhanqi Zhao
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany. .,Department of Biomedical Engineering, Fourth Military Medical University, 169 Changle Xi Rd, Xi'an, China.
| |
Collapse
|
22
|
Hentze B, Muders T, Hoog Antink C, Putensen C, Larsson A, Hedenstierna G, Walter M, Leonhardt S. A model-based source separation algorithm for lung perfusion imaging using electrical impedance tomography. Physiol Meas 2021; 42. [PMID: 34167091 DOI: 10.1088/1361-6579/ac0e84] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 06/24/2021] [Indexed: 11/11/2022]
Abstract
Objective. Electrical impedance tomography (EIT) for lung perfusion imaging is attracting considerable interest in intensive care, as it might open up entirely new ways to adjust ventilation therapy. A promising technique is bolus injection of a conductive indicator to the central venous catheter, which yields the indicator-based signal (IBS). Lung perfusion images are then typically obtained from the IBS using the maximum slope technique. However, the low spatial resolution of EIT results in a partial volume effect (PVE), which requires further processing to avoid regional bias.Approach. In this work, we repose the extraction of lung perfusion images from the IBS as a source separation problem to account for the PVE. We then propose a model-based algorithm, called gamma decomposition (GD), to derive an efficient solution. The GD algorithm uses a signal model to transform the IBS into a parameter space where the source signals of heart and lung are separable by clustering in space and time. Subsequently, it reconstructs lung model signals from which lung perfusion images are unambiguously extracted.Main results. We evaluate the GD algorithm on EIT data of a prospective animal trial with eight pigs. The results show that it enables lung perfusion imaging using EIT at different stages of regional impairment. Furthermore, parameters of the source signals seem to represent physiological properties of the cardio-pulmonary system.Significance. This work represents an important advance in IBS processing that will likely reduce bias of EIT perfusion images and thus eventually enable imaging of regional ventilation/perfusion (V/Q) ratio.
Collapse
Affiliation(s)
- Benjamin Hentze
- Medical Information Technology, RWTH Aachen University, Pauwelsstr. 20, 52074 Aachen, Germany.,Department of Anaesthesiology and Intensive Care Medicine, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Thomas Muders
- Department of Anaesthesiology and Intensive Care Medicine, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Christoph Hoog Antink
- Medical Information Technology, RWTH Aachen University, Pauwelsstr. 20, 52074 Aachen, Germany.,Biomedical Engineering, TU Darmstadt, Darmstadt, Germany
| | - Christian Putensen
- Department of Anaesthesiology and Intensive Care Medicine, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Anders Larsson
- Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
| | | | - Marian Walter
- Medical Information Technology, RWTH Aachen University, Pauwelsstr. 20, 52074 Aachen, Germany
| | - Steffen Leonhardt
- Medical Information Technology, RWTH Aachen University, Pauwelsstr. 20, 52074 Aachen, Germany
| |
Collapse
|
23
|
Spinelli E, Kircher M, Stender B, Ottaviani I, Basile MC, Marongiu I, Colussi G, Grasselli G, Pesenti A, Mauri T. Unmatched ventilation and perfusion measured by electrical impedance tomography predicts the outcome of ARDS. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2021; 25:192. [PMID: 34082795 PMCID: PMC8173510 DOI: 10.1186/s13054-021-03615-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Accepted: 05/21/2021] [Indexed: 12/30/2022]
Abstract
Background In acute respiratory distress syndrome (ARDS), non-ventilated perfused regions coexist with non-perfused ventilated regions within lungs. The number of unmatched regions might reflect ARDS severity and affect the risk of ventilation-induced lung injury. Despite pathophysiological relevance, unmatched ventilation and perfusion are not routinely assessed at the bedside. The aims of this study were to quantify unmatched ventilation and perfusion at the bedside by electrical impedance tomography (EIT) investigating their association with mortality in patients with ARDS and to explore the effects of positive end-expiratory pressure (PEEP) on unmatched ventilation and perfusion in subgroups of patients with different ARDS severity based on PaO2/FiO2 and compliance. Methods Prospective observational study in 50 patients with mild (36%), moderate (46%), and severe (18%) ARDS under clinical ventilation settings. EIT was applied to measure the regional distribution of ventilation and perfusion using central venous bolus of saline 5% during end-inspiratory pause. We defined unmatched units as the percentage of only ventilated units plus the percentage of only perfused units. Results Percentage of unmatched units was significantly higher in non-survivors compared to survivors (32[27–47]% vs. 21[17–27]%, p < 0.001). Percentage of unmatched units was an independent predictor of mortality (OR 1.22, 95% CI 1.07–1.39, p = 0.004) with an area under the ROC curve of 0.88 (95% CI 0.79–0.97, p < 0.001). The percentage of ventilation to the ventral region of the lung was higher than the percentage of ventilation to the dorsal region (32 [27–38]% vs. 18 [13–21]%, p < 0.001), while the opposite was true for perfusion (28 [22–38]% vs. 36 [32–44]%, p < 0.001). Higher percentage of only perfused units was correlated with lower dorsal ventilation (r = − 0.486, p < 0.001) and with lower PaO2/FiO2 ratio (r = − 0.293, p = 0.039). Conclusions EIT allows bedside assessment of unmatched ventilation and perfusion in mechanically ventilated patients with ARDS. Measurement of unmatched units could identify patients at higher risk of death and could guide personalized treatment.
Collapse
Affiliation(s)
- Elena Spinelli
- Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy
| | - Michael Kircher
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | | | - Irene Ottaviani
- Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy
| | - Maria C Basile
- Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy
| | - Ines Marongiu
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Giulia Colussi
- Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy
| | - Giacomo Grasselli
- Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy.,Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Antonio Pesenti
- Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy.,Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Tommaso Mauri
- Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy. .,Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy.
| |
Collapse
|
24
|
Jiang H, Li Q, Yu X, Zhang C, Li Y, Niu G, Tong ZH, Xi JN, Zhao Z. Ventilation improvement after pneumonia treatment evaluated with electrical impedance tomography: an observational study. Physiol Meas 2021; 42. [PMID: 33971628 DOI: 10.1088/1361-6579/abffbf] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 05/10/2021] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Due to radiation exposures, not all patients with pneumonia would receive chest x-ray or CT measurements to confirm treatment effectiveness. The aim of the study was to examine the ability of using electrical impedance tomography (EIT) to evaluate the treatment effectiveness in such patient group. METHODS A total of 35 consecutive patients with non-severe pneumonia was included in this prospective study. The patients received standard treatment according to our internal protocol. EIT measurements were performed in supine position before the treatment start and on day 6 of the treatment period. EIT-based global inhomogeneity (GI) index and center of ventilation index (CoV) were calculated. Clinical pulmonary infection score (CPIS) was obtained at both time points. RESULTS Clinically significant improvements in GI and CoV were found in patient group (ΔGI: -34%±17% and ΔCoV: -10%±11%; p<0.001). Although CPIS was also significantly improved (ΔCPIS -0.70±0.17, p<0.001), no correlations were demonstrated when it compared to ΔGI or ΔCoV. CONCLUSION EIT demonstrated individual improvement of ventilation heterogeneity after standard treatment in non-severe pneumonia, which provided different information compared to CPIS. EIT has the potential to become a routine non-invasive, non-radiative tool to assess pneumonia treatment effectiveness.
Collapse
Affiliation(s)
- Hongying Jiang
- Department of Respiratory and Critical Care Medicine, Beijing Chao-Yang Hospital, Beijing, Beijing, CHINA
| | - Qing Li
- Department of Respiratory Rehabilitation Centre, Beijing Rehabilitation Hospital of Capital Medical University, Beijing, CHINA
| | - Xin Yu
- Department of Respiratory Rehabilitation Centre, Beijing Rehabilitation Hospital of Capital Medical University, Beijing, CHINA
| | - Chenxi Zhang
- Department of Respiratory Rehabilitation Centre, Beijing Rehabilitation Hospital of Capital Medical University, Beijing, CHINA
| | - Yi Li
- Department of Respiratory Rehabilitation Centre, Beijing Rehabilitation Hospital of Capital Medical University, Beijing, CHINA
| | - Guangyu Niu
- Department of Respiratory Rehabilitation Centre, Beijing Rehabilitation Hospital of Capital Medical University, Beijing, CHINA
| | - Zhao-Hui Tong
- Department of Respiratory and Critical Care Medicine, Beijing Chao-Yang Hospital, Beijing, Beijing, CHINA
| | - Jia-Ning Xi
- Department of Respiratory Rehabilitation Centre, Beijing Rehabilitation Hospital of Capital Medical University, Beijing, CHINA
| | - Zhanqi Zhao
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, 710032, CHINA
| |
Collapse
|
25
|
Yang L, Dai M, Cao X, Möller K, Dargvainis M, Frerichs I, Becher T, Fu F, Zhao Z. Regional ventilation distribution in healthy lungs: can reference values be established for electrical impedance tomography parameters? ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:789. [PMID: 34268402 PMCID: PMC8246208 DOI: 10.21037/atm-20-7442] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 01/24/2021] [Indexed: 12/26/2022]
Abstract
Background Although electrical impedance tomography (EIT) is widely used for monitoring regional ventilation distribution, reference values have yet to be established for clinical use. The present study aimed to evaluate the feasibility of creating reference values for standard EIT parameters for potential clinical application. Methods A total of 75 participants with healthy lungs were included in this prospective study (male:female, 48:27; age, 34±14 years; height, 172±7 cm; weight, 73±12 kg). The subjects were examined during spontaneous breathing in the supine position. EIT measurements were performed at the level of the 4th intercostal space. Commonly used EIT-based parameters, including the center of ventilation (CoV), dorsal and most dorsal fractions of ventilation distribution (TVD and TVROI4 respectively), global inhomogeneity (GI) index, and standard deviation of regional ventilation delay index (RVDSD) were calculated. Results Following outlier detection, EIT data from 71 subjects were finally evaluated. The values of the evaluated parameters were: CoV, 48.7%±1.7%; TVD, 48.1%±5.4%; TVROI4, 7.1%±1.8%; GI, 0.49±0.04; and RVDSD, 7.0±2.0. The coefficients of variation for CoV and GI were low (0.03 and 0.07, respectively), but those for TVROI4 and RVDSD were comparatively high (0.26 and 0.28, respectively). None of the evaluated parameters showed a significant correlation with age. The GI index showed a weak but significant correlation with body mass index (R=0.29, P=0.01). The RVDSD was slightly higher in males than in females. Conclusions Our study indicated that CoV and GI were stable parameters with small coefficients of variation in participants with healthy lungs. The creation of EIT parameter reference values for setting treatment targets may be feasible.
Collapse
Affiliation(s)
- Lin Yang
- Department of Aerospace Medicine, Fourth Military Medical University, Xi'an, China
| | - Meng Dai
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Xinsheng Cao
- Department of Aerospace Medicine, Fourth Military Medical University, Xi'an, China
| | - Knut Möller
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
| | - Mantas Dargvainis
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre of Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - Inéz Frerichs
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre of Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - Tobias Becher
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre of Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - Feng Fu
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Zhanqi Zhao
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China.,Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
| |
Collapse
|
26
|
Wang Y, Zhong M. Bedside Evaluation of Pulmonary Embolism by Saline Contrast-enhanced Electrical Impedance Tomography: Considerations for Future Research. Am J Respir Crit Care Med 2021; 203:394-395. [PMID: 33091323 PMCID: PMC7874307 DOI: 10.1164/rccm.202009-3640le] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Yuxian Wang
- Zhongshan Hospital Affiliated to Fudan University Shanghai, China
| | - Ming Zhong
- Zhongshan Hospital Affiliated to Fudan University Shanghai, China
| |
Collapse
|
27
|
He H, Long Y, Chi Y, Yuan S, Zhao Z. Reply to Wang and Zhong: Bedside Evaluation of Pulmonary Embolism by Saline Contrast-enhanced Electrical Impedance Tomography: Considerations for Future Research. Am J Respir Crit Care Med 2021; 203:395-397. [PMID: 33091316 PMCID: PMC7874319 DOI: 10.1164/rccm.202010-3768le] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Huaiwu He
- Peking Union Medical College HospitalBeijing, China
- State Key Laboratory of Complex Severe and Rare DiseasesBeijing, China
| | - Yun Long
- Peking Union Medical College HospitalBeijing, China
- State Key Laboratory of Complex Severe and Rare DiseasesBeijing, China
| | - Yi Chi
- Peking Union Medical College HospitalBeijing, China
- State Key Laboratory of Complex Severe and Rare DiseasesBeijing, China
| | - Siyi Yuan
- Peking Union Medical College HospitalBeijing, China
- State Key Laboratory of Complex Severe and Rare DiseasesBeijing, China
| | - Zhanqi Zhao
- Furtwangen UniversityVillingen-Schwenningen, Germanyand
- Fourth Military Medical UniversityXi’an, China
| |
Collapse
|
28
|
Yuan S, He H, Long Y, Chi Y, Frerichs I, Zhao Z. Rapid dynamic bedside assessment of pulmonary perfusion defect by electrical impedance tomography in a patient with acute massive pulmonary embolism. Pulm Circ 2021; 11:2045894020984043. [PMID: 33532059 PMCID: PMC7829466 DOI: 10.1177/2045894020984043] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 06/07/2020] [Indexed: 12/21/2022] Open
Abstract
Several animal studies have shown that regional lung perfusion could be
effectively estimated by the hypertonic saline contrast electrical impedance
tomography method. Here, we reported an application of this method to
dynamically assess regional pulmonary perfusion defect in a patient with acute
massive pulmonary embolism. A 68-year-old man experienced sudden dyspnea and
cardiac arrest during out-of-bed physical activity on the first day after
partial mediastinal tumor resection. Acute pulmonary embolism was suspected due
to acute enlargement of right heart and fixed inferior venous cava measured with
bedside ultrasound. The computed tomography pulmonary angiography further
confirmed large embolism in both left and right main pulmonary arteries and
branches. The regional time impedance curves, which were obtained by a bolus of
10 ml 10% NaCl through the central venous catheter, were then analyzed to
quantitatively assess regional perfusion. Normal ventilation distribution with
massive defects in regional perfusion in both lungs was observed, leading to a
ventilation–perfusion mismatch and low oxygenation index
(PaO2/FiO2 = 86 mmHg) at the first day of pulmonary embolism. The
anticoagulation was performed with heparin, and the patient’s condition (such as
shock, dyspnea, hypoxemia, etc.), regional lung perfusion defect, and
ventilation–perfusion mismatch continuously improved in the following days. In
conclusion, this case implies that electrical impedance tomography might have
the potential to assess and monitor regional perfusion for rapid diagnosis of
fatal pulmonary embolism in clinical practice.
Collapse
Affiliation(s)
- 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 Science, Beijing, 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 Science, 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 Science, Beijing, China
| | - Yi Chi
- 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 Science, Beijing, China
| | - Inéz Frerichs
- Department of Anesthesiology and Intensive Care Medicine, University Medical Center of Schleswig-Holstein, Kiel, Germany
| | - Zhanqi Zhao
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China.,Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
| |
Collapse
|
29
|
Kircher M, Elke G, Stender B, Hernandez Mesa M, Schuderer F, Dossel O, Fuld MK, Halaweish AF, Hoffman EA, Weiler N, Frerichs I. Regional Lung Perfusion Analysis in Experimental ARDS by Electrical Impedance and Computed Tomography. IEEE TRANSACTIONS ON MEDICAL IMAGING 2021; 40:251-261. [PMID: 32956046 DOI: 10.1109/tmi.2020.3025080] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Electrical impedance tomography is clinically used to trace ventilation related changes in electrical conductivity of lung tissue. Estimating regional pulmonary perfusion using electrical impedance tomography is still a matter of research. To support clinical decision making, reliable bedside information of pulmonary perfusion is needed. We introduce a method to robustly detect pulmonary perfusion based on indicator-enhanced electrical impedance tomography and validate it by dynamic multidetector computed tomography in two experimental models of acute respiratory distress syndrome. The acute injury was induced in a sublobar segment of the right lung by saline lavage or endotoxin instillation in eight anesthetized mechanically ventilated pigs. For electrical impedance tomography measurements, a conductive bolus (10% saline solution) was injected into the right ventricle during breath hold. Electrical impedance tomography perfusion images were reconstructed by linear and normalized Gauss-Newton reconstruction on a finite element mesh with subsequent element-wise signal and feature analysis. An iodinated contrast agent was used to compute pulmonary blood flow via dynamic multidetector computed tomography. Spatial perfusion was estimated based on first-pass indicator dilution for both electrical impedance and multidetector computed tomography and compared by Pearson correlation and Bland-Altman analysis. Strong correlation was found in dorsoventral (r = 0.92) and in right-to-left directions (r = 0.85) with good limits of agreement of 8.74% in eight lung segments. With a robust electrical impedance tomography perfusion estimation method, we found strong agreement between multidetector computed and electrical impedance tomography perfusion in healthy and regionally injured lungs and demonstrated feasibility of electrical impedance tomography perfusion imaging.
Collapse
|
30
|
Borges JB, Alcala GC, Mlček M. A Step Forward toward a Bedside and Timely Monitoring of Regional [Formula: see text]/[Formula: see text] Matching. Am J Respir Crit Care Med 2020; 202:1342-1344. [PMID: 32833499 PMCID: PMC7667916 DOI: 10.1164/rccm.202007-2896ed] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Affiliation(s)
| | | | - Mikuláš Mlček
- Institute of PhysiologyCharles UniversityPrague, Czech Republicand
| |
Collapse
|
31
|
Safaee Fakhr B, Araujo Morais CC, De Santis Santiago RR, Di Fenza R, Gibson LE, Restrepo PA, Chang MG, Bittner EA, Pinciroli R, Fintelmann FJ, Kacmarek RM, Berra L. Bedside monitoring of lung perfusion by electrical impedance tomography in the time of COVID-19. Br J Anaesth 2020; 125:e434-e436. [PMID: 32859359 PMCID: PMC7413127 DOI: 10.1016/j.bja.2020.08.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 08/02/2020] [Indexed: 02/07/2023] Open
Affiliation(s)
- Bijan Safaee Fakhr
- Department of Anaesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Caio C Araujo Morais
- Department of Anaesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Roberta R De Santis Santiago
- Department of Anaesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Raffaele Di Fenza
- Department of Anaesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Lauren E Gibson
- Department of Anaesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Paula A Restrepo
- Department of Anaesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Marvin G Chang
- Department of Anaesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Edward A Bittner
- Department of Anaesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Riccardo Pinciroli
- Department of Anaesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Florian J Fintelmann
- Harvard Medical School, Boston, MA, USA; Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Robert M Kacmarek
- Department of Anaesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA; Respiratory Care Department, Massachusetts General Hospital, Boston, MA, USA
| | - Lorenzo Berra
- Department of Anaesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA; Respiratory Care Department, Massachusetts General Hospital, Boston, MA, USA.
| |
Collapse
|
32
|
He H, Chi Y, Long Y, Yuan S, Frerichs I, Möller K, Fu F, Zhao Z. Influence of overdistension/recruitment induced by high positive end-expiratory pressure on ventilation-perfusion matching assessed by electrical impedance tomography with saline bolus. Crit Care 2020; 24:586. [PMID: 32993811 PMCID: PMC7523261 DOI: 10.1186/s13054-020-03301-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 09/21/2020] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND High positive end-expiratory pressures (PEEP) may induce overdistension/recruitment and affect ventilation-perfusion matching (VQMatch) in mechanically ventilated patients. This study aimed to investigate the association between PEEP-induced lung overdistension/recruitment and VQMatch by electrical impedance tomography (EIT). METHODS The study was conducted prospectively on 30 adult mechanically ventilated patients: 18/30 with ARDS and 12/30 with high risk for ARDS. EIT measurements were performed at zero end-expiratory pressures (ZEEP) and subsequently at high (12-15 cmH2O) PEEP. The number of overdistended pixels over the number of recruited pixels (O/R ratio) was calculated, and the patients were divided into low O/R (O/R ratio < 15%) and high O/R groups (O/R ratio ≥ 15%). The global inhomogeneity (GI) index was calculated to evaluate the ventilation distribution. Lung perfusion image was calculated from the EIT impedance-time curves caused by 10 ml 10% NaCl injection during a respiratory pause (> 8 s). DeadSpace%, Shunt%, and VQMatch% were calculated based on lung EIT perfusion and ventilation images. RESULTS Increasing PEEP resulted in recruitment mainly in dorsal regions and overdistension mainly in ventral regions. ΔVQMatch% (VQMatch% at high PEEP minus that at ZEEP) was significantly correlated with recruited pixels (r = 0.468, P = 0.009), overdistended pixels (r = - 0.666, P < 0.001), O/R ratio (r = - 0.686, P < 0.001), and ΔSpO2 (r = 0.440, P = 0.015). Patients in the low O/R ratio group (14/30) had significantly higher Shunt% and lower VQMatch% than those in the high O/R ratio group (16/30) at ZEEP but not at high PEEP. Comparable DeadSpace% was found in both groups. A high PEEP caused a significant improvement of VQMatch%, DeadSpace%, Shunt%, and GI in the low O/R ratio group, but not in the high O/R ratio group. Using O/R ratio of 15% resulted in a sensitivity of 81% and a specificity of 100% for an increase of VQMatch% > 20% in response to high PEEP. CONCLUSIONS Change of ventilation-perfusion matching was associated with regional overdistention and recruitment induced by PEEP. A low O/R ratio induced by high PEEP might indicate a more homogeneous ventilation and improvement of VQMatch. TRIAL REGISTRATION ClinicalTrials.gov, NCT04081155 . Registered on 9 September 2019-retrospectively registered.
Collapse
Affiliation(s)
- Huaiwu He
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Yi Chi
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Yun Long
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
| | - Siyi Yuan
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Inéz Frerichs
- Department of Anesthesiology and Intensive Care Medicine, University Medical Center of Schleswig-Holstein Campus kiel, Kiel 24105, Germany
| | - Knut Möller
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
| | - Feng Fu
- Department of Biomedical Engineering, Fourth Military Medical University, 169 Changle Xi Rd, Xi'an, China
| | - Zhanqi Zhao
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany.
- Department of Biomedical Engineering, Fourth Military Medical University, 169 Changle Xi Rd, Xi'an, China.
| |
Collapse
|