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Ekkapat G, Ribeiro De Santis Santiago R, Victor M, Berra L. Electrical Impedance Tomography for Assessing the Impact of Inhaled Nitric Oxide on Pulmonary Artery Pressure. Anesthesiology 2024; 141:377-378. [PMID: 38743612 DOI: 10.1097/aln.0000000000004972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Affiliation(s)
- Gamonmas Ekkapat
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Department of Anesthesiology, Faculty of Medicine, Chulalongkorn University, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand
| | - Roberta Ribeiro De Santis Santiago
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Marcus Victor
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Electronics Engineering, Aeronautics Institute of Technology, São José dos Campos, Brazil
| | - Lorenzo Berra
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
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Torsani V, Cardoso PFG, Borges JB, Gomes S, Moriya HT, Cruz AFD, Santiago RRDS, Nagao CK, Fitipaldi MF, Beraldo MDA, Junior MHV, Mlček M, Pego-Fernandes PM, Amato MBP. First real-time imaging of bronchoscopic lung volume reduction by electrical impedance tomography. Respir Res 2024; 25:264. [PMID: 38965590 PMCID: PMC11225379 DOI: 10.1186/s12931-024-02877-0] [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: 03/27/2024] [Accepted: 06/11/2024] [Indexed: 07/06/2024] Open
Abstract
BACKGROUND Bronchoscopic lung volume reduction (BLVR) with one-way endobronchial valves (EBV) has better outcomes when the target lobe has poor collateral ventilation, resulting in complete lobe atelectasis. High-inspired oxygen fraction (FIO2) promotes atelectasis through faster gas absorption after airway occlusion, but its application during BLVR with EBV has been poorly understood. We aimed to investigate the real-time effects of FIO2 on regional lung volumes and regional ventilation/perfusion by electrical impedance tomography (EIT) during BLVR with EBV. METHODS Six piglets were submitted to left lower lobe occlusion by a balloon-catheter and EBV valves with FIO2 0.5 and 1.0. Regional end-expiratory lung impedances (EELI) and regional ventilation/perfusion were monitored. Local pocket pressure measurements were obtained (balloon occlusion method). One animal underwent simultaneous acquisitions of computed tomography (CT) and EIT. Regions-of-interest (ROIs) were right and left hemithoraces. RESULTS Following balloon occlusion, a steep decrease in left ROI-EELI with FIO2 1.0 occurred, 3-fold greater than with 0.5 (p < 0.001). Higher FIO2 also enhanced the final volume reduction (ROI-EELI) achieved by each valve (p < 0.01). CT analysis confirmed the denser atelectasis and greater volume reduction achieved by higher FIO2 (1.0) during balloon occlusion or during valve placement. CT and pocket pressure data agreed well with EIT findings, indicating greater strain redistribution with higher FIO2. CONCLUSIONS EIT demonstrated in real-time a faster and more complete volume reduction in the occluded lung regions under high FIO2 (1.0), as compared to 0.5. Immediate changes in the ventilation and perfusion of ipsilateral non-target lung regions were also detected, providing better estimates of the full impact of each valve in place. TRIAL REGISTRATION Not applicable.
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Affiliation(s)
- Vinicius Torsani
- Divisao de Pneumologia, Instituto do Coracao, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brasil
| | - Paulo Francisco Guerreiro Cardoso
- Division of Thoracic Surgery, Thoracic Surgery Research Laboratory (LIM 61), Instituto do Coracao, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brasil
| | - João Batista Borges
- Institute of Physiology, First Faculty of Medicine, Charles University, Albertov 5, Prague, 128 00, Czech Republic.
| | - Susimeire Gomes
- Divisao de Pneumologia, Instituto do Coracao, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brasil
| | - Henrique Takachi Moriya
- Biomedical Engineering Laboratory, Escola Politecnica da Universidade de Sao Paulo, Sao Paulo, Brasil
| | - Andrea Fonseca da Cruz
- Biomedical Engineering Laboratory, Escola Politecnica da Universidade de Sao Paulo, Sao Paulo, Brasil
| | | | - Cristopher Kengo Nagao
- Division of Thoracic Surgery, Thoracic Surgery Research Laboratory (LIM 61), Instituto do Coracao, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brasil
| | - Mariana Fernandes Fitipaldi
- Division of Thoracic Surgery, Thoracic Surgery Research Laboratory (LIM 61), Instituto do Coracao, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brasil
| | - Marcelo do Amaral Beraldo
- Divisao de Pneumologia, Instituto do Coracao, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brasil
| | - Marcus Henrique Victor Junior
- Divisao de Pneumologia, Instituto do Coracao, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brasil
| | - Mikuláš Mlček
- Institute of Physiology, First Faculty of Medicine, Charles University, Albertov 5, Prague, 128 00, Czech Republic
| | - Paulo Manuel Pego-Fernandes
- Division of Thoracic Surgery, Thoracic Surgery Research Laboratory (LIM 61), Instituto do Coracao, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brasil
| | - Marcelo Britto Passos Amato
- Divisao de Pneumologia, Instituto do Coracao, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brasil
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Atmaca Ö, Liu J, Ly TJ, Bajraktari F, Pott PP. Spatial sensitivity distribution assessment and Monte Carlo simulations for needle-based bioimpedance imaging during venipuncture using the finite element method. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2024; 40:e3831. [PMID: 38690649 DOI: 10.1002/cnm.3831] [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: 10/26/2023] [Revised: 04/05/2024] [Accepted: 04/15/2024] [Indexed: 05/02/2024]
Abstract
Despite being among the most common medical procedures, needle insertions suffer from a high error rate. Impedance measurements using electrode-equipped needles offer promise for improved tissue targeting and reduced errors. Impedance visualization usually requires an extensive pre-measured impedance dataset for tissue differentiation and knowledge of the electric fields contributing to the resulting impedances. This work presents two finite element simulation approaches for both problems. The first approach describes the generation of a multitude of impedances with Monte Carlo simulations for both, homogeneous and inhomogeneous tissue to circumvent the need to rely on previously measured data. These datasets could be used for tissue discrimination. The second method describes the simulation of the spatial sensitivity distribution of an electrode layout. Two singularity analysis methods were employed to determine the bulk of the sensitivity within a finite volume, which in turn enables consistent 3D visualization. The modeled electrode layout consists of 12 electrodes radially placed around a hypodermic needle. Electrical excitation was simulated using two neighboring electrodes for current carriage and voltage pickup, which resulted in 12 distinct bipolar excitation states. Both, the impedance simulations and the respective singularity analysis methods were compared with each other. The results show that the statistical spread of impedances is highly dependent on the tissue type and its inhomogeneities. The bounded bulk of sensitivities of both methods are of similar extent and symmetry. Future models should incorporate more detailed tissue properties such as anisotropy or changing material properties due to tissue deformation to gain more accurate predictions.
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Affiliation(s)
- Ömer Atmaca
- Institute of Medical Device Technology (IMT), University of Stuttgart, Baden-Württemberg, Germany
- Institute of Applied Optics (ITO), University of Stuttgart, Stuttgart, Baden-Württemberg, Germany
| | - Jan Liu
- Institute of Medical Device Technology (IMT), University of Stuttgart, Baden-Württemberg, Germany
| | - Toni J Ly
- Institute of Medical Device Technology (IMT), University of Stuttgart, Baden-Württemberg, Germany
- Fraunhofer Institute for Manufacturing Engineering and Automation (IPA), Stuttgart, Baden-Württemberg, Germany
| | - Flakë Bajraktari
- Institute of Medical Device Technology (IMT), University of Stuttgart, Baden-Württemberg, Germany
| | - Peter P Pott
- Institute of Medical Device Technology (IMT), University of Stuttgart, Baden-Württemberg, 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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Songsangvorn N, Xu Y, Lu C, Rotstein O, Brochard L, Slutsky AS, Burns KEA, Zhang H. Electrical impedance tomography-guided positive end-expiratory pressure titration in ARDS: a systematic review and meta-analysis. Intensive Care Med 2024; 50:617-631. [PMID: 38512400 PMCID: PMC11078723 DOI: 10.1007/s00134-024-07362-2] [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: 12/16/2023] [Accepted: 02/14/2024] [Indexed: 03/23/2024]
Abstract
PURPOSE Assessing efficacy of electrical impedance tomography (EIT) in optimizing positive end-expiratory pressure (PEEP) for acute respiratory distress syndrome (ARDS) patients to enhance respiratory system mechanics and prevent ventilator-induced lung injury (VILI), compared to traditional methods. METHODS We carried out a systematic review and meta-analysis, spanning literature from January 2012 to May 2023, sourced from Scopus, PubMed, MEDLINE (Ovid), Cochrane, and LILACS, evaluated EIT-guided PEEP strategies in ARDS versus conventional methods. Thirteen studies (3 randomized, 10 non-randomized) involving 623 ARDS patients were analyzed using random-effects models for primary outcomes (respiratory mechanics and mechanical power) and secondary outcomes (PaO2/FiO2 ratio, mortality, stays in intensive care unit (ICU), ventilator-free days). RESULTS EIT-guided PEEP significantly improved lung compliance (n = 941 cases, mean difference (MD) = 4.33, 95% confidence interval (CI) [2.94, 5.71]), reduced mechanical power (n = 148, MD = - 1.99, 95% CI [- 3.51, - 0.47]), and lowered driving pressure (n = 903, MD = - 1.20, 95% CI [- 2.33, - 0.07]) compared to traditional methods. Sensitivity analysis showed consistent positive effect of EIT-guided PEEP on lung compliance in randomized clinical trials vs. non-randomized studies pooled (MD) = 2.43 (95% CI - 0.39 to 5.26), indicating a trend towards improvement. A reduction in mortality rate (259 patients, relative risk (RR) = 0.64, 95% CI [0.45, 0.91]) was associated with modest improvements in compliance and driving pressure in three studies. CONCLUSIONS EIT facilitates real-time, individualized PEEP adjustments, improving respiratory system mechanics. Integration of EIT as a guiding tool in mechanical ventilation holds potential benefits in preventing ventilator-induced lung injury. Larger-scale studies are essential to validate and optimize EIT's clinical utility in ARDS management.
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Affiliation(s)
- Nickjaree Songsangvorn
- Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Toronto, ON, Canada
- Department of Critical Care Medicine, Bhumibol Adulyadej Hospital, Bangkok, Thailand
| | - Yonghao Xu
- Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Toronto, ON, Canada.
- The State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
| | - Cong Lu
- Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Toronto, ON, Canada
| | - Ori Rotstein
- Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Toronto, ON, Canada
- Department of Surgery, University of Toronto, Toronto, ON, Canada
| | - Laurent Brochard
- Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Toronto, ON, Canada
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada
| | - Arthur S Slutsky
- Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Toronto, ON, Canada
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada
| | - Karen E A Burns
- Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Toronto, ON, Canada
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada
| | - Haibo Zhang
- Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Toronto, ON, Canada.
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada.
- Department of Physiology, University of Toronto, Toronto, ON, Canada.
- Department of Anesthesiology and Pain Medicine, University of Toronto, Toronto, ON, Canada.
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Ribeiro BM, Tucci MR, Victor Júnior MH, Melo JR, Gomes S, Nakamura MAM, Morais CCA, Beraldo MA, Lima CAS, Alcala GC, Amato MBP. Influence of Fractional Inspired Oxygen Tension on Lung Perfusion Distribution, Regional Ventilation, and Lung Volume during Mechanical Ventilation of Supine Healthy Swine. Anesthesiology 2024; 140:752-764. [PMID: 38207290 DOI: 10.1097/aln.0000000000004903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
BACKGROUND Lower fractional inspired oxygen tension (Fio2) during general anesthesia can reduce lung atelectasis. The objectives are to evaluate the effect of two Fio2 (0.4 and 1) during low positive end-expiratory pressure (PEEP) ventilation over lung perfusion distribution, volume, and regional ventilation. These variables were evaluated at two PEEP levels and unilateral lung atelectasis. METHODS In this exploratory study, 10 healthy female piglets (32.3 ± 3.4 kg) underwent mechanical ventilation in two atelectasis models: (1) bilateral gravitational atelectasis (n = 6), induced by changes in PEEP and Fio2 in three combinations: high PEEP with low Fio2 (Fio2 = 0.4), zero PEEP (PEEP0) with low Fio2 (Fio2 = 0.4), and PEEP0 with high Fio2 (Fio2 = 1); and (2) unilateral atelectasis (n = 6), induced by left bronchial occlusion, with the left lung aerated (Fio2 = 0.21) and low aerated (Fio2 = 1; n = 5 for this step). Measurements were conducted after 10 min in each step, encompassing assessment of respiratory mechanics, oxygenation, and hemodynamics; lung ventilation and perfusion by electrical impedance tomography; and lung aeration and perfusion by computed tomography. RESULTS During bilateral gravitational atelectasis, PEEP reduction increased atelectasis in dorsal regions, decreased respiratory compliance, and distributed lung ventilation to ventral regions with a parallel shift of perfusion to the same areas. With PEEP0, there were no differences between low and high Fio2 in respiratory compliance (23.9 ± 6.5 ml/cm H2O vs. 21.9 ± 5.0; P = 0.441), regional ventilation, and regional perfusion, despite higher lung collapse (18.6 ± 7.6% vs. 32.7 ± 14.5%; P = 0.045) with high Fio2. During unilateral lung atelectasis, the deaerated lung had a lower shunt (19.3 ± 3.6% vs. 25.3 ± 5.5%; P = 0.045) and lower computed tomography perfusion to the left lung (8.8 ± 1.8% vs. 23.8 ± 7.1%; P = 0.007). CONCLUSIONS PEEP0 with low Fio2, compared with high Fio2, did not produce significant changes in respiratory system compliance, regional lung ventilation, and perfusion despite significantly lower lung collapse. After left bronchial occlusion, the shrinkage of the parenchyma with Fio2 = 1 enhanced hypoxic pulmonary vasoconstriction, reducing intrapulmonary shunt and perfusion of the nonventilated areas. EDITOR’S PERSPECTIVE
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Affiliation(s)
- Bruno M Ribeiro
- Laboratorio de Pneumologia LIM-09, Disciplina de Pneumologia, Instituto de Cardiologia (Incor), Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Mauro R Tucci
- Laboratorio de Pneumologia LIM-09, Disciplina de Pneumologia, Instituto de Cardiologia (Incor), Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Marcus H Victor Júnior
- Laboratorio de Pneumologia LIM-09, Disciplina de Pneumologia, Instituto de Cardiologia (Incor), Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, Brazil; Electronics Engineering, Aeronautics Institute of Technology, Sao Jose dos Campos, Brazil
| | - Jose R Melo
- Laboratorio de Pneumologia LIM-09, Disciplina de Pneumologia, Instituto de Cardiologia (Incor), Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Susimeire Gomes
- Laboratorio de Pneumologia LIM-09, Disciplina de Pneumologia, Instituto de Cardiologia (Incor), Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Maria A M Nakamura
- Laboratorio de Pneumologia LIM-09, Disciplina de Pneumologia, Instituto de Cardiologia (Incor), Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Caio C A Morais
- Laboratorio de Pneumologia LIM-09, Disciplina de Pneumologia, Instituto de Cardiologia (Incor), Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Marcelo A Beraldo
- Laboratorio de Pneumologia LIM-09, Disciplina de Pneumologia, Instituto de Cardiologia (Incor), Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Cristhiano A S Lima
- Laboratorio de Pneumologia LIM-09, Disciplina de Pneumologia, Instituto de Cardiologia (Incor), Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Glasiele C Alcala
- Laboratorio de Pneumologia LIM-09, Disciplina de Pneumologia, Instituto de Cardiologia (Incor), Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Marcelo B P Amato
- Laboratorio de Pneumologia LIM-09, Disciplina de Pneumologia, Instituto de Cardiologia (Incor), Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, Brazil
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Cenci S, Santiago RDS, Bittner EA, Berra L. Assessing Regional Lung Perfusion Changes to Inhaled Pulmonary Vasodilators by Electrical Impedance Tomography. Am J Respir Crit Care Med 2023; 208:e39-e40. [PMID: 37450762 DOI: 10.1164/rccm.202302-0247im] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 07/14/2023] [Indexed: 07/18/2023] Open
Affiliation(s)
- Stefano Cenci
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Harvard University, Boston, Massachusetts; and
| | - Roberta De Santis Santiago
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Harvard University, Boston, Massachusetts; and
| | - Edward A Bittner
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Harvard University, Boston, Massachusetts; and
| | - Lorenzo Berra
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Harvard University, Boston, Massachusetts; and
- Respiratory Care Services, Massachusetts General Hospital, Boston, Massachusetts
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Ribeiro De Santis Santiago R, Xin Y, Gaulton TG, Alcala G, León Bueno de Camargo ED, Cereda M, Britto Passos Amato M, Berra L. Lung Imaging Acquisition with Electrical Impedance Tomography: Tackling Common Pitfalls. Anesthesiology 2023; 139:329-341. [PMID: 37402247 DOI: 10.1097/aln.0000000000004613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/06/2023]
Abstract
Electrical impedance tomography is a powerful tool for lung imaging that can be employed at the bedside in multiple clinical scenarios. Diagnosing and preventing interpretation pitfalls will ensure reliable data and allow for appropriate clinical decision-making.
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Affiliation(s)
- Roberta Ribeiro De Santis Santiago
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Yi Xin
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Timothy G Gaulton
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Glasiele Alcala
- Pulmonary Division, Heart Institute (InCor), University of São Paulo, São Paulo, Brazil
| | - Erick Dario León Bueno de Camargo
- Federal University of ABC/Engineering, Modeling and Applied Social Sciences Centre, Biomedical Engineering, São Bernardo do Campo, Brazil
| | - Maurizio Cereda
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | | | - Lorenzo Berra
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
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Marrazzo F, Spina S, Zadek F, Forlini C, Bassi G, Giudici R, Bellani G, Fumagalli R, Langer T. PEEP Titration Is Markedly Affected by Trunk Inclination in Mechanically Ventilated Patients with COVID-19 ARDS: A Physiologic, Cross-Over Study. J Clin Med 2023; 12:3914. [PMID: 37373608 PMCID: PMC10299565 DOI: 10.3390/jcm12123914] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 06/04/2023] [Accepted: 06/06/2023] [Indexed: 06/29/2023] Open
Abstract
BACKGROUND Changing trunk inclination affects lung function in patients with ARDS. However, its impacts on PEEP titration remain unknown. The primary aim of this study was to assess, in mechanically ventilated patients with COVID-19 ARDS, the effects of trunk inclination on PEEP titration. The secondary aim was to compare respiratory mechanics and gas exchange in the semi-recumbent (40° head-of-the-bed) and supine-flat (0°) positions following PEEP titration. METHODS Twelve patients were positioned both at 40° and 0° trunk inclination (randomized order). The PEEP associated with the best compromise between overdistension and collapse guided by Electrical Impedance Tomography (PEEPEIT) was set. After 30 min of controlled mechanical ventilation, data regarding respiratory mechanics, gas exchange, and EIT parameters were collected. The same procedure was repeated for the other trunk inclination. RESULTS PEEPEIT was lower in the semi-recumbent than in the supine-flat position (8 ± 2 vs. 13 ± 2 cmH2O, p < 0.001). A semi-recumbent position with optimized PEEP resulted in higher PaO2:FiO2 (141 ± 46 vs. 196 ± 99, p = 0.02) and a lower global inhomogeneity index (46 ± 10 vs. 53 ± 11, p = 0.008). After 30 min of observation, a loss of aeration (measured by EIT) was observed only in the supine-flat position (-153 ± 162 vs. 27 ± 203 mL, p = 0.007). CONCLUSIONS A semi-recumbent position is associated with lower PEEPEIT and results in better oxygenation, less derecruitment, and more homogenous ventilation compared to the supine-flat position.
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Affiliation(s)
- Francesco Marrazzo
- Department of Anesthesia and Critical Care, ASST Grande Ospedale Metropolitano Niguarda, 20162 Milano, Italy; (F.M.); (S.S.); (C.F.); (G.B.); (R.G.); (R.F.)
| | - Stefano Spina
- Department of Anesthesia and Critical Care, ASST Grande Ospedale Metropolitano Niguarda, 20162 Milano, Italy; (F.M.); (S.S.); (C.F.); (G.B.); (R.G.); (R.F.)
| | - Francesco Zadek
- School of Medicine and Surgery, University of Milano-Bicocca, 20126 Milano, Italy; (F.Z.); (G.B.)
| | - Clarissa Forlini
- Department of Anesthesia and Critical Care, ASST Grande Ospedale Metropolitano Niguarda, 20162 Milano, Italy; (F.M.); (S.S.); (C.F.); (G.B.); (R.G.); (R.F.)
| | - Gabriele Bassi
- Department of Anesthesia and Critical Care, ASST Grande Ospedale Metropolitano Niguarda, 20162 Milano, Italy; (F.M.); (S.S.); (C.F.); (G.B.); (R.G.); (R.F.)
| | - Riccardo Giudici
- Department of Anesthesia and Critical Care, ASST Grande Ospedale Metropolitano Niguarda, 20162 Milano, Italy; (F.M.); (S.S.); (C.F.); (G.B.); (R.G.); (R.F.)
| | - Giacomo Bellani
- School of Medicine and Surgery, University of Milano-Bicocca, 20126 Milano, Italy; (F.Z.); (G.B.)
- Department of Anesthesia and Intensive Care 1, Santa Chiara Hospital, APSS Trento, 38122 Trento, Italy
| | - Roberto Fumagalli
- Department of Anesthesia and Critical Care, ASST Grande Ospedale Metropolitano Niguarda, 20162 Milano, Italy; (F.M.); (S.S.); (C.F.); (G.B.); (R.G.); (R.F.)
- School of Medicine and Surgery, University of Milano-Bicocca, 20126 Milano, Italy; (F.Z.); (G.B.)
| | - Thomas Langer
- Department of Anesthesia and Critical Care, ASST Grande Ospedale Metropolitano Niguarda, 20162 Milano, Italy; (F.M.); (S.S.); (C.F.); (G.B.); (R.G.); (R.F.)
- School of Medicine and Surgery, University of Milano-Bicocca, 20126 Milano, Italy; (F.Z.); (G.B.)
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10
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Lima CA, Campos SL, Bandeira MP, Leite WS, Brandão DC, Fernandes J, Fink JB, Dornelas de Andrade A. Influence of Mechanical Ventilation Modes on the Efficacy of Nebulized Bronchodilators in the Treatment of Intubated Adult Patients with Obstructive Pulmonary Disease. Pharmaceutics 2023; 15:pharmaceutics15051466. [PMID: 37242708 DOI: 10.3390/pharmaceutics15051466] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 05/03/2023] [Accepted: 05/06/2023] [Indexed: 05/28/2023] Open
Abstract
BACKGROUND Little has been reported in terms of clinical outcomes to confirm the benefits of nebulized bronchodilators during mechanical ventilation (MV). Electrical Impedance Tomography (EIT) could be a valuable method to elucidate this gap. OBJECTIVE The purpose of this study is to evaluate the impact of nebulized bronchodilators during invasive MV with EIT by comparing three ventilation modes on the overall and regional lung ventilation and aeration in critically ill patients with obstructive pulmonary disease. METHOD A blind clinical trial in which eligible patients underwent nebulization with salbutamol sulfate (5 mg/1 mL) and ipratropium bromide (0.5 mg/2 mL) in the ventilation mode they were receiving. EIT evaluation was performed before and after the intervention. A joint and stratified analysis into ventilation mode groups was performed, with p < 0.05. RESULTS Five of nineteen procedures occurred in controlled MV mode, seven in assisted mode and seven in spontaneous mode. In the intra-group analysis, the nebulization increased total ventilation in controlled (p = 0.04 and ⅆ = 2) and spontaneous (p = 0.01 and ⅆ = 1.5) MV modes. There was an increase in the dependent pulmonary region in assisted mode (p = 0.01 and ⅆ = 0.3) and in spontaneous mode (p = 0.02 and ⅆ = 1.6). There was no difference in the intergroup analysis. CONCLUSIONS Nebulized bronchodilators reduce the aeration of non-dependent pulmonary regions and increase overall lung ventilation but there was no difference between the ventilation modes. As a limitation, it is important to note that the muscular effort in PSV and A/C PCV modes influences the impedance variation, and consequently the aeration and ventilation values. Thus, future studies are needed to evaluate this effort as well as the time on ventilator, time in UCI and other variables.
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Affiliation(s)
- Cibelle Andrade Lima
- Physiotherapy Depatment, Universidade Federal do Rio Grande do Norte, Natal 59078-970, RN, Brazil
| | - Shirley Lima Campos
- Physiotherapy Depatment, Universidade Federal de Pernambuco, Recife 50740-560, PE, Brazil
| | | | - Wagner Souza Leite
- Physiotherapy Depatment, Universidade Federal de Pernambuco, Recife 50740-560, PE, Brazil
| | - Daniella Cunha Brandão
- Physiotherapy Depatment, Universidade Federal de Pernambuco, Recife 50740-560, PE, Brazil
| | - Juliana Fernandes
- Physiotherapy Depatment, Universidade Federal de Pernambuco, Recife 50740-560, PE, Brazil
| | - James B Fink
- Department of Cardiopulmonary Science, Division of Respiratory, CA Rush University Medical Center, Chicago, IL 60612, USA
- Aerogen Pharma, San Mateo, CA 94402, USA
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11
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Sun T, Yu L, Deng D, Yu M, Chen Y, Chang C, Chen M, Chen S, Chen X, Lin H. Three-dimensional magneto-acousto-electrical tomography (3D MAET) with single-element ultrasound transducer and coded excitation: a phantom validation study. Neurocomputing 2023. [DOI: 10.1016/j.neucom.2023.02.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2023]
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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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Herrmann J, Kollisch-Singule M, Satalin J, Nieman GF, Kaczka DW. Assessment of Heterogeneity in Lung Structure and Function During Mechanical Ventilation: A Review of Methodologies. JOURNAL OF ENGINEERING AND SCIENCE IN MEDICAL DIAGNOSTICS AND THERAPY 2022; 5:040801. [PMID: 35832339 PMCID: PMC9132008 DOI: 10.1115/1.4054386] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 04/13/2022] [Indexed: 06/15/2023]
Abstract
The mammalian lung is characterized by heterogeneity in both its structure and function, by incorporating an asymmetric branching airway tree optimized for maintenance of efficient ventilation, perfusion, and gas exchange. Despite potential benefits of naturally occurring heterogeneity in the lungs, there may also be detrimental effects arising from pathologic processes, which may result in deficiencies in gas transport and exchange. Regardless of etiology, pathologic heterogeneity results in the maldistribution of regional ventilation and perfusion, impairments in gas exchange, and increased work of breathing. In extreme situations, heterogeneity may result in respiratory failure, necessitating support with a mechanical ventilator. This review will present a summary of measurement techniques for assessing and quantifying heterogeneity in respiratory system structure and function during mechanical ventilation. These methods have been grouped according to four broad categories: (1) inverse modeling of heterogeneous mechanical function; (2) capnography and washout techniques to measure heterogeneity of gas transport; (3) measurements of heterogeneous deformation on the surface of the lung; and finally (4) imaging techniques used to observe spatially-distributed ventilation or regional deformation. Each technique varies with regard to spatial and temporal resolution, degrees of invasiveness, risks posed to patients, as well as suitability for clinical implementation. Nonetheless, each technique provides a unique perspective on the manifestations and consequences of mechanical heterogeneity in the diseased lung.
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Affiliation(s)
- Jacob Herrmann
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA 52242
| | | | - Joshua Satalin
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY 13210
| | - Gary F. Nieman
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY 13210
| | - David W. Kaczka
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA 52242; Department of Anesthesia, University of Iowa, Iowa City, IA 52242; Department of Radiology, University of Iowa, Iowa City, IA 52242
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14
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Biselli PJC, Degobbi Tenorio Quirino Dos Santos Lopes F, Righetti RF, Moriya HT, Tibério IFLC, Martins MA. Lung Mechanics Over the Century: From Bench to Bedside and Back to Bench. Front Physiol 2022; 13:817263. [PMID: 35910573 PMCID: PMC9326096 DOI: 10.3389/fphys.2022.817263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 06/17/2022] [Indexed: 11/13/2022] Open
Abstract
Lung physiology research advanced significantly over the last 100 years. Respiratory mechanics applied to animal models of lung disease extended the knowledge of the workings of respiratory system. In human research, a better understanding of respiratory mechanics has contributed to development of mechanical ventilators. In this review, we explore the use of respiratory mechanics in basic science to investigate asthma and chronic obstructive pulmonary disease (COPD). We also discuss the use of lung mechanics in clinical care and its role on the development of modern mechanical ventilators. Additionally, we analyse some bench-developed technologies that are not in widespread use in the present but can become part of the clinical arsenal in the future. Finally, we explore some of the difficult questions that intensive care doctors still face when managing respiratory failure. Bringing back these questions to bench can help to solve them. Interaction between basic and translational science and human subject investigation can be very rewarding, as in the conceptualization of “Lung Protective Ventilation” principles. We expect this interaction to expand further generating new treatments and managing strategies for patients with respiratory disease.
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Affiliation(s)
- Paolo Jose Cesare Biselli
- Intensive Care Unit, University Hospital, University of Sao Paulo, Sao Paulo, Brazil
- *Correspondence: Paolo Jose Cesare Biselli,
| | | | - Renato Fraga Righetti
- Laboratory of Experimental Therapeutics, Department of Clinical Medicine, School of Medicine, University of Sao Paulo, Sao Paulo, Brazil
- Hospital Sírio-Libanês, Serviço de Reabilitação, São Paulo, Brazil
| | - Henrique Takachi Moriya
- Biomedical Engineering Laboratory, Escola Politecnica, University of Sao Paulo, Sao Paulo, Brazil
| | - Iolanda Fátima Lopes Calvo Tibério
- Laboratory of Experimental Therapeutics, Department of Clinical Medicine, School of Medicine, University of Sao Paulo, Sao Paulo, Brazil
| | - Milton Arruda Martins
- Laboratory of Experimental Therapeutics, Department of Clinical Medicine, School of Medicine, University of Sao Paulo, Sao Paulo, Brazil
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15
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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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16
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Influence of the end inspiratory pause on respiratory mechanics and tidal gas distribution of surgical patients ventilated under a tailored open lung approach strategy: A randomised, crossover trial. Anaesth Crit Care Pain Med 2022; 41:101038. [DOI: 10.1016/j.accpm.2022.101038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 12/09/2021] [Accepted: 12/12/2021] [Indexed: 11/21/2022]
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17
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Li Z, Qin S, Chen C, Mei S, Yao Y, Zhao Z, Li W, Deng Y, Gao Y. Emerging Trends and Hot Spots of Electrical Impedance Tomography Applications in Clinical Lung Monitoring. Front Med (Lausanne) 2022; 8:813640. [PMID: 35174185 PMCID: PMC8841839 DOI: 10.3389/fmed.2021.813640] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 12/28/2021] [Indexed: 12/14/2022] Open
Abstract
Objective This study explores the emerging trends and hot topics concerning applications on electrical impedance tomography (EIT) in clinical lung monitoring. Methods Publications on EIT applications in clinical lung monitoring in 2001–2021 were extracted from the Web of Science Core Collection (WoSCC). The search strategy was “electrical impedance tomography” and “lung.” CiteSpace, a VOS viewer was used to study the citation characteristics, cooperation, and keyword co-occurrence. Moreover, co-cited reference clustering, structural variation analysis (SVA), and future research trends were presented. Results Six hundred and thirty-six publications were included for the final analysis. The global annual publications on clinical lung monitoring gradually increased in the last two decades. Germany contributes 32.2% of total global publications. University Medical Center Schleswig-Holstein (84 publications, cited frequency 2,205), Physiological Measurement (105 publications, cited frequency 2,056), and Inéz Frerichs (116 articles, cited frequency 3,609) were the institution, journal, and author with the largest number of article citations in the research field. “Electrical impedance tomography” (occurrences, 304), “mechanical ventilation” (occurrences, 99), and “acute respiratory distress syndrome” (occurrences, 67) were the top most three frequent keywords, “noninvasive monitoring” (Avg, pub, year: 2008.17), and “extracorporeal membrane oxygenation” (Avg, pub, year: 2019.60) were the earliest and latest keywords. The keywords “electrical impedance tomography” (strength 7.88) and co-cited reference “Frerichs I, 2017, THORAX” (strength 47.45) had the highest burst value. “Driving pressure,” “respiratory failure,” and “titration” are the three keywords still maintaining a high brush value until now. The largest and smallest cluster of the co-cited references are “obstructive lung diseases” (#0, size: 97) and “lung perfusion” (#20, size: 5). Co-cited reference “Frerichs I, 2017, THORAX” (modularity change rate: 98.49) has the highest structural variability. Categories with most and least interdisciplinary crossing are “ENGINEERING” and “CRITICAL CARE MEDICINE.” Conclusions EIT is a valuable technology for clinical lung monitoring, gradually converting from imaging techniques to the clinic. Research hot spots may continue monitoring techniques, the ventilation distribution of acute respiratory distress syndrome (ARDS), and respiratory therapy strategies. More diversified lung function monitoring studies, such as lung perfusion and interdisciplinary crossing, are potentially emerging research trends.
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Affiliation(s)
- Zhe Li
- Department of Critical Care Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Shaojie Qin
- Department of Critical Care Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Chen Chen
- Department of Critical Care Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Shuya Mei
- Department of Critical Care Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yulong Yao
- Department of Critical Care Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Zhanqi Zhao
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
| | - Wen Li
- Department of Critical Care Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- *Correspondence: Wen Li
| | - Yuxiao Deng
- Department of Critical Care Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Yuxiao Deng
| | - Yuan Gao
- Department of Critical Care Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Yuan Gao
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18
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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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19
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Xin Y, Martin K, Morais CC, Delvecchio P, Gerard SE, Hamedani H, Herrmann J, Abate N, Lenart A, Humayun S, Sidhu U, Petrov M, Reutlinger K, Mandelbaum T, Duncan I, Tustison N, Kadlecek S, Chatterjee S, Gee JC, Rizi RR, Berra L, Cereda M. Diminishing Efficacy of Prone Positioning With Late Application in Evolving Lung Injury. Crit Care Med 2021; 49:e1015-e1024. [PMID: 33938714 PMCID: PMC8448902 DOI: 10.1097/ccm.0000000000005071] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES It is not known how lung injury progression during mechanical ventilation modifies pulmonary responses to prone positioning. We compared the effects of prone positioning on regional lung aeration in late versus early stages of lung injury. DESIGN Prospective, longitudinal imaging study. SETTING Research imaging facility at The University of Pennsylvania (Philadelphia, PA) and Medical and Surgical ICUs at Massachusetts General Hospital (Boston, MA). SUBJECTS Anesthetized swine and patients with acute respiratory distress syndrome (acute respiratory distress syndrome). INTERVENTIONS Lung injury was induced by bronchial hydrochloric acid (3.5 mL/kg) in 10 ventilated Yorkshire pigs and worsened by supine nonprotective ventilation for 24 hours. Whole-lung CT was performed 2 hours after hydrochloric acid (Day 1) in both prone and supine positions and repeated at 24 hours (Day 2). Prone and supine images were registered (superimposed) in pairs to measure the effects of positioning on the aeration of each tissue unit. Two patients with early acute respiratory distress syndrome were compared with two patients with late acute respiratory distress syndrome, using electrical impedance tomography to measure the effects of body position on regional lung mechanics. MEASUREMENTS AND MAIN RESULTS Gas exchange and respiratory mechanics worsened over 24 hours, indicating lung injury progression. On Day 1, prone positioning reinflated 18.9% ± 5.2% of lung mass in the posterior lung regions. On Day 2, position-associated dorsal reinflation was reduced to 7.3% ± 1.5% (p < 0.05 vs Day 1). Prone positioning decreased aeration in the anterior lungs on both days. Although prone positioning improved posterior lung compliance in the early acute respiratory distress syndrome patients, it had no effect in late acute respiratory distress syndrome subjects. CONCLUSIONS The effects of prone positioning on lung aeration may depend on the stage of lung injury and duration of prior ventilation; this may limit the clinical efficacy of this treatment if applied late.
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Affiliation(s)
- Yi Xin
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Kevin Martin
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
| | - Caio C.A. Morais
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Paolo Delvecchio
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
| | - Sarah E. Gerard
- Department of Radiology, University of Iowa, Iowa City, IA, USA
| | - Hooman Hamedani
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Jacob Herrmann
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Nicholas Abate
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
| | - Austin Lenart
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
| | - Shiraz Humayun
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
| | - Uday Sidhu
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
| | - Mihail Petrov
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
| | - Kristan Reutlinger
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
| | - Tal Mandelbaum
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
| | - Ian Duncan
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Nicholas Tustison
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, USA
| | - Stephen Kadlecek
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Shampa Chatterjee
- Department of Physiology, University of Pennsylvania, Philadelphia, PA, USA
| | - James C. Gee
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Rahim R. Rizi
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Lorenzo Berra
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Maurizio Cereda
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
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20
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Lin BS, Yu HR, Kuo YT, Liu YW, Chen HY, Lin BS. Wearable Electrical Impedance Tomography Belt With Dry Electrodes. IEEE Trans Biomed Eng 2021; 69:955-962. [PMID: 34495826 DOI: 10.1109/tbme.2021.3110527] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Electrical impedance tomography (EIT) is a noninvasive imaging technology used to reconstruct the conductivity distribution in objects and the human body. In recent years, numerous EIT systems and image reconstruction algorithms have been developed. However, most of these EIT systems require conventional electrodes with conductive gels (wet electrodes) and cannot be adapted to different body types, resulting in limited applicability. In this study, a wearable wireless EIT belt with dry electrodes was designed to enable EIT imaging of the human body without using wet electrodes. The specific design of the belt mechanism and dry electrodes provide the advantages of easy wear and adaptation to different body sizes. Additionally, the GaussNewton method was used to optimize the EIT image. Finally, experiments were performed on the phantom and human body to validate the performance of the proposed EIT belt. The results demonstrate that the proposed system can provide accurate location information of the objects in the EIT image and the system can be successfully applied for noninvasive measurement of the human body.
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21
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Pigatto AV, Kao TJ, Mueller JL, Baker CD, DeBoer EM, Kupfer O. Electrical impedance tomography detects changes in ventilation after airway clearance in spinal muscular atrophy type I. Respir Physiol Neurobiol 2021; 294:103773. [PMID: 34400355 DOI: 10.1016/j.resp.2021.103773] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 04/06/2021] [Accepted: 08/05/2021] [Indexed: 11/18/2022]
Abstract
The effect of mechanical insufflation-exsufflation (MIE) for airway clearance in patients with spinal muscular atrophy type I (SMA-I) on the distribution of ventilation in the lung is unknown, as is the duration of its beneficial effects. A pilot study to investigate the feasibility of using three dimensional (3-D) electrical impedance tomography (EIT) images to estimate lung volumes pre- and post-MIE for assessing the effectiveness of mechanical insufflation-exsufflation (MIE) was conducted in 6 pediatric patients with SMA-I in the neuromuscular clinic at Children's Hospital Colorado. EIT data were collected before, during, and after the MIE procedure on two rows of 16 electrodes placed around the chest. Lung volumes were computed from the images and compared before, during, and after the MIE procedure to assess the ability of EIT to estimate changes in lung volume during insufflation and exsufflation. Images of pulsatile pulmonary perfusion were computed in subjects able to perform breath-holding. In four of the six subjects, lung volumes during tidal breathing increased after MIE (average change from pre to post MIE was 58.8±55.1 mL). The time-dependent plots of lung volume computed from the EIT data clearly show when the MIE device insufflates and exsufflates air and the rest periods between mechanical coughs. Images of pulmonary pulsatile perfusion were computed from data collected during breathing pauses. The results suggest that EIT holds promise for estimating lung volumes and ventilation/perfusion mismatch, both of which are useful for assessing the effectiveness of MIE in clearing mucus plugs.
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Affiliation(s)
- Andre Viera Pigatto
- School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523, United States
| | - Tzu-Jen Kao
- GE Research, Niskayuna, NY 12309, United States
| | - Jennifer L Mueller
- School of Biomedical Engineering and Department of Mathematics, Colorado State University, Fort Collins, CO 80523, United States.
| | - Christopher D Baker
- Department of Pediatrics, Section of Pulmonary Medicine, University of Colorado School of Medicine, Aurora, CO 80045, United States
| | - Emily M DeBoer
- Department of Pediatrics, Section of Pulmonary Medicine, University of Colorado School of Medicine, Aurora, CO 80045, United States
| | - Oren Kupfer
- Department of Pediatrics, Section of Pulmonary Medicine, University of Colorado School of Medicine, Aurora, CO 80045, United States
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22
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Huang S, Wang YC, Ju S. Advances in medical imaging to evaluate acute respiratory distress syndrome. ACTA ACUST UNITED AC 2021; 5:1-9. [PMID: 34308253 PMCID: PMC8286037 DOI: 10.1007/s42058-021-00078-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 06/09/2021] [Accepted: 07/08/2021] [Indexed: 11/12/2022]
Abstract
Acute respiratory distress syndrome is a refractory respiratory syndrome with a high prevalence in the Intensive Care Unit. Though much improvement has been achieved over the last 50 decades, the disease continues to be under-recognized and under-treated, and its mortality remains high. Since the first report, the radiologic examination has been an essential part in evaluating this disease. Chest X-ray radiography and computed tomography are conventional imaging techniques in routine clinical practice. Other image modalities, including lung ultrasound, electrical impedance tomography, positron emission tomography, have demonstrated their respective advantages over recent years but have not yet been broadly applied in clinical practice. Among these modalities, computed tomography and its quantitative analysis have shown an irreplaceable power in diagnosis, intervention evaluation and prognostic prediction. In this review, we briefly introduced the basics of acute respiratory distress syndrome and summarized imaging advances. In addition, we focused on the computed tomography modality and highlighted the value of its quantitative assessment.
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Affiliation(s)
- Shan Huang
- Department of Radiology, Jiangsu Key Laboratory of Molecular and Functional Imaging, School of Medicine, Zhongda Hospital, Southeast University, 87 Ding Jia Qiao Road, Nanjing, 210009 Jiangsu China
| | - Yuan-Cheng Wang
- Department of Radiology, Jiangsu Key Laboratory of Molecular and Functional Imaging, School of Medicine, Zhongda Hospital, Southeast University, 87 Ding Jia Qiao Road, Nanjing, 210009 Jiangsu China.,Jiangsu Provincial Key Laboratory of Critical Care Medicine, Southeast University, Nanjing, 210009 China
| | - Shenghong Ju
- Department of Radiology, Jiangsu Key Laboratory of Molecular and Functional Imaging, School of Medicine, Zhongda Hospital, Southeast University, 87 Ding Jia Qiao Road, Nanjing, 210009 Jiangsu China
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Abstract
PURPOSE OF REVIEW Among noninvasive lung imaging techniques that can be employed at the bedside electrical impedance tomography (EIT) and lung ultrasound (LUS) can provide dynamic, repeatable data on the distribution regional lung ventilation and response to therapeutic manoeuvres.In this review, we will provide an overview on the rationale, basic functioning and most common applications of EIT and Point of Care Ultrasound (PoCUS, mainly but not limited to LUS) in the management of mechanically ventilated patients. RECENT FINDINGS The use of EIT in clinical practice is supported by several studies demonstrating good correlation between impedance tomography data and other validated methods of assessing lung aeration during mechanical ventilation. Similarly, LUS also correlates with chest computed tomography in assessing lung aeration, its changes and several pathological conditions, with superiority over other techniques. Other PoCUS applications have shown to effectively complement the LUS ultrasound assessment of the mechanically ventilated patient. SUMMARY Bedside techniques - such as EIT and PoCUS - are becoming standards of the care for mechanically ventilated patients to monitor the changes in lung aeration, ventilation and perfusion in response to treatment and to assess weaning from mechanical ventilation.
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Assessment of Electrical Impedance Tomography to Set Optimal Positive End-Expiratory Pressure for Venoarterial Extracorporeal Membrane Oxygenation-Treated Patients. Crit Care Med 2021; 49:923-933. [PMID: 33595959 DOI: 10.1097/ccm.0000000000004892] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Patients on venoarterial extracorporeal membrane oxygenation have many risk factors for pulmonary complications in addition to their heart failure. Optimal positive end-expiratory pressure is unknown in these patients. The aim was to evaluate the ability of electrical impedance tomography to help the physician to select the optimal positive end-expiratory pressure in venoarterial extracorporeal membrane oxygenation treated and mechanically ventilated patients during a positive end-expiratory pressure trial. DESIGN Observational prospective monocentric. SETTING University hospital. PATIENTS Patients (n = 23) older than 18 years old, on mechanical ventilation and venoarterial extracorporeal membrane oxygenation. INTERVENTIONS A decreasing positive end-expiratory pressure trial (20-5 cm H2O) in increments of 5 cm H2O was performed and monitored by a collection of clinical parameters, ventilatory and ultrasonographic (cardiac and pulmonary) to define an optimal positive end-expiratory pressure according to respiratory criteria (optimal positive end-expiratory pressure selected by physician with respiratory parameters), and then adjusted according to hemodynamic and cardiac tolerances (optimal positive end-expiratory pressure selected by physician with respiratory, hemodynamic, and echocardiographic parameters). At the same time, electrical impedance tomography data (regional distribution of ventilation, compliance, and overdistension collapse) were recorded and analyzed retrospectively to define the optimal positive end-expiratory pressure. MEASUREMENTS AND MAIN RESULTS The median of this optimal positive end-expiratory pressure was 10 cm H2O in our population. Electrical impedance tomography showed that increasing positive end-expiratory pressure promoted overdistention of ventral lung, maximum at positive end-expiratory pressure 20 cm H20 (34% [interquartile range, 24.5-40]). Decreasing positive end-expiratory pressure resulted in collapse of dorsal lung (29% [interquartile range, 21-45.8]). The optimal positive end-expiratory pressure selected by physician with respiratory parameters was not different from the positive end-expiratory pressure chosen by the electrical impedance tomography. However, there is a negative impact of a high level of intrathoracic pressure on hemodynamic and cardiac tolerances. CONCLUSIONS Our results support that electrical impedance tomography appears predictive to define optimal positive end-expiratory pressure on venoarterial extracorporeal membrane oxygenation, aided by echocardiography to optimize hemodynamic assessment and management.
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Cornejo R, Iturrieta P, Olegário TMM, Kajiyama C, Arellano D, Guiñez D, Cerda MA, Brito R, Gajardo AIJ, Lazo M, López L, Morais CCA, González S, Zavala M, Rojas V, Medel JN, Hurtado DE, Bruhn A, Ramos C, Estuardo N. Estimation of changes in cyclic lung strain by electrical impedance tomography: Proof-of-concept study. Acta Anaesthesiol Scand 2021; 65:228-235. [PMID: 33037607 DOI: 10.1111/aas.13723] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 09/15/2020] [Accepted: 10/01/2020] [Indexed: 02/06/2023]
Abstract
RATIONALE Cyclic strain may be a determinant of ventilator-induced lung injury. The standard for strain assessment is the computed tomography (CT), which does not allow continuous monitoring and exposes to radiation. Electrical impedance tomography (EIT) is able to monitor changes in regional lung ventilation. In addition, there is a correlation between mechanical deformation of materials and detectable changes in its electrical impedance, making EIT a potential surrogate for cyclic lung strain measured by CT (StrainCT ). OBJECTIVES To compare the global StrainCT with the change in electrical impedance (ΔZ). METHODS Acute respiratory distress syndrome patients under mechanical ventilation (VT 6 mL/kg ideal body weight with positive end-expiratory pressure 5 [PEEP 5] and best PEEP according to EIT) underwent whole-lung CT at end-inspiration and end-expiration. Biomechanical analysis was used to construct 3D maps and determine StrainCT at different levels of PEEP. CT and EIT acquisitions were performed simultaneously. Multilevel analysis was employed to determine the causal association between StrainCT and ΔZ. Linear regression models were used to predict the change in lung StrainCT between different PEEP levels based on the change in ΔZ. MAIN RESULTS StrainCT was positively and independently associated with ΔZ at global level (P < .01). Furthermore, the change in StrainCT (between PEEP 5 and Best PEEP) was accurately predicted by the change in ΔZ (R2 0.855, P < .001 at global level) with a high agreement between predicted and measured StrainCT . CONCLUSIONS The change in electrical impedance may provide a noninvasive assessment of global cyclic strain, without radiation at bedside.
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Affiliation(s)
- Rodrigo Cornejo
- Unidad de Pacientes Críticos Departamento de Medicina Hospital Clínico Universidad de Chile Santiago Chile
- Center of Acute Respiratory Critical Illness (ARCI) Santiago Chile
| | - Pablo Iturrieta
- Department of Structural and Geotechnical Engineering School of Engineering Pontificia Universidad Católica de Chile Santiago Chile
| | | | | | - Daniel Arellano
- Unidad de Pacientes Críticos Departamento de Medicina Hospital Clínico Universidad de Chile Santiago Chile
- Departamento de kinesiología Facultad de Medicina Universidad de Chile Santiago Chile
| | - Dannette Guiñez
- Unidad de Pacientes Críticos Departamento de Medicina Hospital Clínico Universidad de Chile Santiago Chile
| | - María A. Cerda
- Unidad de Pacientes Críticos Departamento de Medicina Hospital Clínico Universidad de Chile Santiago Chile
| | - Roberto Brito
- Unidad de Pacientes Críticos Departamento de Medicina Hospital Clínico Universidad de Chile Santiago Chile
| | - Abraham I. J. Gajardo
- Unidad de Pacientes Críticos Departamento de Medicina Hospital Clínico Universidad de Chile Santiago Chile
| | - Marioli Lazo
- Unidad de Pacientes Críticos Departamento de Medicina Hospital Clínico Universidad de Chile Santiago Chile
| | - Lorena López
- Departamento de Radiología Hospital Clínico Universidad de Chile Santiago Chile
| | - Caio C. A. Morais
- Divisao de Pneumologia Faculdade de Medicina Instituto do Coracao Hospital das Clinicas HCFMUSP Universidade de Sao Paulo Sao Paulo Brazil
| | - Sedric González
- Unidad de Pacientes Críticos Departamento de Medicina Hospital Clínico Universidad de Chile Santiago Chile
| | - Miguel Zavala
- Unidad de Pacientes Críticos Departamento de Medicina Hospital Clínico Universidad de Chile Santiago Chile
| | - Verónica Rojas
- Unidad de Pacientes Críticos Departamento de Medicina Hospital Clínico Universidad de Chile Santiago Chile
| | - Juan N. Medel
- Unidad de Pacientes Críticos Departamento de Medicina Hospital Clínico Universidad de Chile Santiago Chile
| | - Daniel E. Hurtado
- Department of Structural and Geotechnical Engineering School of Engineering Pontificia Universidad Católica de Chile Santiago Chile
- Institute for Biological and Medical Engineering School of Engineering Pontificia Universidad Católica de Chile Santiago Chile
| | - Alejandro Bruhn
- Center of Acute Respiratory Critical Illness (ARCI) Santiago Chile
- Departamento de Medicina Intensiva Facultad de Medicina Pontificia Universidad Católica de Chile Santiago Chile
| | - Cristobal Ramos
- Departamento de Radiología Hospital Clínico Universidad de Chile Santiago Chile
| | - Nivia Estuardo
- Unidad de Pacientes Críticos Departamento de Medicina Hospital Clínico Universidad de Chile Santiago Chile
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Comparini RG, Falcão MC, Johnston C, Carvalho WBD. Electrical Impedance Tomography in Congenital Diaphragmatic Hernia. Clinics (Sao Paulo) 2021; 76:e3210. [PMID: 34287483 PMCID: PMC8266173 DOI: 10.6061/clinics/2021/e3210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Rafael Gonçalves Comparini
- Instituto da Crianca e do Adolescente, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Mario Cicero Falcão
- Instituto da Crianca e do Adolescente, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Cíntia Johnston
- Instituto da Crianca e do Adolescente, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Werther Brunow de Carvalho
- Instituto da Crianca e do Adolescente, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
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Effects of pleural effusion drainage in the mechanically ventilated patient as monitored by electrical impedance tomography and end-expiratory lung volume: A pilot study. J Crit Care 2020; 59:76-80. [DOI: 10.1016/j.jcrc.2020.06.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 04/25/2020] [Accepted: 06/01/2020] [Indexed: 12/17/2022]
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Lima E, Nakamura MAM, Genta PR, Rodrigues AJ, Athanazio RA, Rached S, Costa ELV, Stelmach R. Improving Airways Patency and Ventilation Through Optimal Positive Pressure Identified by Noninvasive Mechanical Ventilation Titration in Mounier-Kuhn Syndrome: Protocol for an Interventional, Open-Label, Single-Arm Clinical Trial. JMIR Res Protoc 2020; 9:e14786. [PMID: 32795996 PMCID: PMC7455860 DOI: 10.2196/14786] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 04/28/2020] [Accepted: 06/02/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Mounier-Kuhn syndrome or congenital tracheobronchomegaly is a rare disease characterized by dilation of the trachea and the main bronchi within the thoracic cavity. The predominant signs and symptoms of the disease include coughing, purulent and abundant expectoration, dyspnea, snoring, wheezing, and recurrent respiratory infection. Symptoms of the disease in some patients are believed to be pathological manifestations arising due to resident tracheobronchomalacia. Although treatment options used for the management of this disease include inhaled bronchodilators, corticosteroids, and hypertonic solution, there is no consensus on the treatment. The use of continuous positive airway pressure (CPAP) has been reported as a potential therapeutic option for tracheobronchomalacia, but no prospective studies have demonstrated its efficacy in this condition. OBJECTIVE The purpose of this is to identify the presence of tracheobronchomalacia and an optimal CPAP pressure that reduces the tracheobronchial collapse in patients with Mounier-Kuhn syndrome and to analyze the repercussion in pulmonary ventilation. In parallel, we aim to evaluate the prevalence of obstructive sleep apnea/hypopnea syndrome. METHODS This interventional, open-label, single-arm clinical trial will enroll patients who are diagnosed Mounier-Kuhn syndrome. Patient evaluation will be conducted in an outpatient clinic and involve 3 visits. Visit 1 will involve the collection and registration of social demographic, clinical, and functional data. Visit 2 will entail polysomnography, bronchoscopy for the evaluation of tracheobronchomalacia, titration of the optimal pressure that reduces the degree of collapse of the airway, and electrical impedance tomography. In visit 3, patients exhibiting a reduction in collapse areas will be requested to undergo chest computed tomography during inspiration and forced expiration with and without positive pressure (titrated to determine optimal CPAP pressure). RESULTS This protocol is a doctorate project. The project was submitted to the institutional review board on January 24, 2017, and approval was granted on February 2, 2017 (Brazilian Research database number CAAE 64001317.4.000.0068). Patient evaluations started in April 2018. Planned recruitment is based on volunteers' availability and clinical stability, and interventions will be conducted at least once a month to finish the project at the end of 2020. A preliminary analysis of each case will be performed after each intervention, but detailed results are expected to be reported in the first quarter of 2021. CONCLUSIONS There is no consensus on the best treatment options for managing Mounier-Kuhn syndrome. The use of positive pressure could maintain patency of the collapsed airways, functioning as a "pneumatic stent" to reduce the degree of airflow obstruction. This, in turn, could promote mobilization of thoracic secretion and improve pulmonary ventilation. TRIAL REGISTRATION ClinicalTrails.gov NCT03101059; https://clinicaltrials.gov/ct2/show/NCT03101059. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID) DERR1-10.2196/14786.
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Affiliation(s)
- Evelise Lima
- Pulmonary Division-Heart Institute (InCor), Hospital das Clínicas da Faculdade de Medicina de São Paulo, São Paulo, Brazil
| | | | - Pedro Rodrigues Genta
- Pulmonary Division-Heart Institute (InCor), Hospital das Clínicas da Faculdade de Medicina de São Paulo, São Paulo, Brazil
| | - Ascedio José Rodrigues
- Pulmonary Division-Heart Institute (InCor), Hospital das Clínicas da Faculdade de Medicina de São Paulo, São Paulo, Brazil
| | - Rodrigo Abensur Athanazio
- Pulmonary Division-Heart Institute (InCor), Hospital das Clínicas da Faculdade de Medicina de São Paulo, São Paulo, Brazil
| | - Samia Rached
- Pulmonary Division-Heart Institute (InCor), Hospital das Clínicas da Faculdade de Medicina de São Paulo, São Paulo, Brazil
| | - Eduardo Leite Vieira Costa
- Pulmonary Division-Heart Institute (InCor), Hospital das Clínicas da Faculdade de Medicina de São Paulo, São Paulo, Brazil
| | - Rafael Stelmach
- Pulmonary Division-Heart Institute (InCor), Hospital das Clínicas da Faculdade de Medicina de São Paulo, São Paulo, Brazil
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Longhini F, Bruni A, Garofalo E, Ronco C, Gusmano A, Cammarota G, Pasin L, Frigerio P, Chiumello D, Navalesi P. Chest physiotherapy improves lung aeration in hypersecretive critically ill patients: a pilot randomized physiological study. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2020; 24:479. [PMID: 32746877 PMCID: PMC7396943 DOI: 10.1186/s13054-020-03198-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 07/22/2020] [Indexed: 12/11/2022]
Abstract
Background Besides airway suctioning, patients undergoing invasive mechanical ventilation (iMV) benefit of different combinations of chest physiotherapy techniques, to improve mucus removal. To date, little is known about the clearance effects of oscillating devices on patients with acute respiratory failure undergoing iMV. This study aimed to assess (1) the effects of high-frequency chest wall oscillation (HFCWO) on lung aeration and ventilation distribution, as assessed by electrical impedance tomography (EIT), and (2) the effect of the association of HFCWO with recruitment manoeuvres (RM). Methods Sixty critically ill patients, 30 classified as normosecretive and 30 as hypersecretive, who received ≥ 48 h of iMV, underwent HFCWO; patients from both subgroups were randomized to receive RM or not, according to two separated randomization sequences. We therefore obtained four arms of 15 patients each. After baseline record (T0), HFCWO was applied for 10 min. At the end of the treatment (T1) or after 1 (T2) and 3 h (T3), EIT data were recorded. At the beginning of each step, closed tracheobronchial suctioning was performed. In the RM subgroup, tracheobronchial suctioning was followed by application of 30 cmH2O to the patient’s airway for 30 s. At each step, we assessed the change in end-expiratory lung impedance (ΔEELI) and in tidal impedance variation (ΔTIV), and the center of gravity (COG) through EIT. We also analysed arterial blood gases (ABGs). Results ΔTIV and COG did not differ between normosecretive and hypersecretive patients. Compared to T0, ΔEELI significantly increased in hypersecretive patients at T2 and T3, irrespective of the RM; on the contrary, no differences were observed in normosecretive patients. No differences of ABGs were recorded. Conclusions In hypersecretive patients, HFCWO significantly improved aeration of the dorsal lung region, without affecting ABGs. The application of RM did not provide any further improvements. Trial registration Prospectively registered at the Australian New Zealand Clinical Trial Registry (www.anzctr.org.au; number of registration: ACTRN12615001257550; date of registration: 17th November 2015).
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Affiliation(s)
- Federico Longhini
- Anesthesia and Intensive Care Unit, Department of Medical and Surgical Sciences, University Hospital Mater Domini, Magna Graecia University, Catanzaro, Italy
| | - Andrea Bruni
- Anesthesia and Intensive Care Unit, Department of Medical and Surgical Sciences, University Hospital Mater Domini, Magna Graecia University, Catanzaro, Italy
| | - Eugenio Garofalo
- Anesthesia and Intensive Care Unit, Department of Medical and Surgical Sciences, University Hospital Mater Domini, Magna Graecia University, Catanzaro, Italy
| | - Chiara Ronco
- Anesthesia and Intensive Care, Sant'Andrea Hospital, ASL VC, Vercelli, Italy
| | - Andrea Gusmano
- Anesthesia and Intensive Care, Sant'Andrea Hospital, ASL VC, Vercelli, Italy
| | - Gianmaria Cammarota
- Department of Anesthesia and Intensive Care, "Maggiore della carità" University Hospital, Novara, Italy
| | - Laura Pasin
- Department of Anesthesia and Intensive Care, Azienda Ospedaliera-Università di Padova, Padua, Italy
| | | | - Davide Chiumello
- SC Anestesia e Rianimazione, Ospedale San Paolo - Polo Universitario, ASST Santi Paolo e Carlo, Milan, Italy.,Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milan, Italy.,Centro Ricerca Coordinata di Insufficienza Respiratoria, Università degli Studi di Milano, Milan, Italy
| | - Paolo Navalesi
- Department of Anesthesia and Intensive Care, Azienda Ospedaliera-Università di Padova, Padua, Italy. .,Dipartimento di Medicina-DIMED, Università degli Studi di Padova, Via Giustiniani, 2 -, 35128, Padova, Italy.
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Borges JB, Cronin JN, Crockett DC, Hedenstierna G, Larsson A, Formenti F. Real-time effects of PEEP and tidal volume on regional ventilation and perfusion in experimental lung injury. Intensive Care Med Exp 2020; 8:10. [PMID: 32086632 PMCID: PMC7035410 DOI: 10.1186/s40635-020-0298-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Accepted: 01/30/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Real-time bedside information on regional ventilation and perfusion during mechanical ventilation (MV) may help to elucidate the physiological and pathophysiological effects of MV settings in healthy and injured lungs. We aimed to study the effects of positive end-expiratory pressure (PEEP) and tidal volume (VT) on the distributions of regional ventilation and perfusion by electrical impedance tomography (EIT) in healthy and injured lungs. METHODS One-hit acute lung injury model was established in 6 piglets by repeated lung lavages (injured group). Four ventilated piglets served as the control group. A randomized sequence of any possible combination of three VT (7, 10, and 15 ml/kg) and four levels of PEEP (5, 8, 10, and 12 cmH2O) was performed in all animals. Ventilation and perfusion distributions were computed by EIT within three regions-of-interest (ROIs): nondependent, middle, dependent. A mixed design with one between-subjects factor (group: intervention or control), and two within-subjects factors (PEEP and VT) was used, with a three-way mixed analysis of variance (ANOVA). RESULTS Two-way interactions between PEEP and group, and VT and group, were observed for the dependent ROI (p = 0.035 and 0.012, respectively), indicating that the increase in the dependent ROI ventilation was greater at higher PEEP and VT in the injured group than in the control group. A two-way interaction between PEEP and VT was observed for perfusion distribution in each ROI: nondependent (p = 0.030), middle (p = 0.006), and dependent (p = 0.001); no interaction was observed between injured and control groups. CONCLUSIONS Large PEEP and VT levels were associated with greater pulmonary ventilation of the dependent lung region in experimental lung injury, whereas they affected pulmonary perfusion of all lung regions both in the control and in the experimental lung injury groups.
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Affiliation(s)
- João Batista Borges
- Centre for Human and Applied Physiological Sciences, King's College London, London, UK.
| | - John N Cronin
- Centre for Human and Applied Physiological Sciences, King's College London, London, UK
| | | | - Göran Hedenstierna
- Hedenstierna Laboratory, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Anders Larsson
- Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
| | - Federico Formenti
- Centre for Human and Applied Physiological Sciences, King's College London, London, UK. .,Nuffield Division of Anaesthetics, University of Oxford, Oxford, UK.
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Rössel T, Uhlig C, Pietsch J, Ludwig S, Koch T, Richter T, Spieth PM, Kersting S. Effects of regional anesthesia techniques on local anesthetic plasma levels and complications in carotid surgery: a randomized controlled pilot trial. BMC Anesthesiol 2019; 19:218. [PMID: 31771512 PMCID: PMC6878670 DOI: 10.1186/s12871-019-0890-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 11/12/2019] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND The ultrasound guided intermediate cervical plexus block with perivascular infiltration of the internal carotid artery (PVB) is a new technique for regional anesthesia in carotid endarterectomy (CEA). We conducted a pilot study investigating the effects of deep cervical block (DCB), intermediate cervical block alone (ICB) and PVB on perioperative complications in patients undergoing elective CEA. We hypothesized, that the ropivacaine plasma concentration is higher in patients receiving DCB compared to PVB and ICB. METHODS In a randomized controlled pilot study thirty patients scheduled for elective CEA were randomly assigned into three groups: DCB receiving 20 mL ropivacaine 0.5% (n = 10), ICB receiving 20 mL ropivacaine 0.5% (n = 10) and PVB receiving 20 mL ropivacaine 0.5% and 10 mL ropivacaine 0,3% (n = 10). As primary outcome, plasma levels of ropivacaine were measured with high performance liquid chromatography before, 5, 10, 20, 60, and 180 min after the injection of ropivacaine. Secondary outcomes were vascular and neurological complications as well as patients' and surgeons' satisfaction. All analyses were performed on an intention-to-treat basis. Statistical significance was accepted at p < 0.05. RESULTS No conversion to general anesthesia was necessary and we observed no signs of local anesthetic intoxication or accidental vascular puncture. Plasma concentration of ropivacaine was significantly higher in the DCB group compared to PVB and ICB (p < 0.001) and in the PVB group compared to ICB (p = 0.008). Surgeons' satisfaction was higher in the PVB group compared to ICB (p = 0.003) and patients' satisfaction was higher in the PVB group compared to ICB (p = 0.010) and DCB group (p = 0.029). Phrenic nerve paralysis was observed frequently in the DCB group (p < 0.05). None of these patients with hemi-diaphragmatic paralysis showed signs of respiratory distress. CONCLUSION The ultrasound guided PVB is a safe and effective technique for CEA which is associated with lower plasma levels of local anesthetic than the standard DCB. Considering the low rate of complications in all types of regional anesthesia for CEA, larger randomized controlled trials are warranted to assess potential side effects among the blocks. TRIAL REGISTRATION The trial was registered at German Clinical Trials Register (DRKS) on 04/05/2019 (DRKS00016705, retrospectively registered).
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Affiliation(s)
- Thomas Rössel
- Department of Anaesthesiology and Critical Care Medicine, University Hospital Carl Gustav Carus Dresden, Technische Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany.
| | - Christopher Uhlig
- Department of Anaesthesiology and Critical Care Medicine, University Hospital Carl Gustav Carus Dresden, Technische Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany
| | - Jörg Pietsch
- Institute of Legal Medicine, Technische Universität Dresden, Dresden, Germany
| | - Stefan Ludwig
- Department of Visceral, Thoracic and Vascular Surgery, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Thea Koch
- Department of Anaesthesiology and Critical Care Medicine, University Hospital Carl Gustav Carus Dresden, Technische Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany
| | - Torsten Richter
- Department of Anaesthesiology and Critical Care Medicine, University Hospital Carl Gustav Carus Dresden, Technische Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany
| | - Peter Markus Spieth
- Department of Anaesthesiology and Critical Care Medicine, University Hospital Carl Gustav Carus Dresden, Technische Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany
| | - Stephan Kersting
- Department of Visceral, Thoracic and Vascular Surgery, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.,Department of General Surgery, University Hospital of Friedrich-Alexander-University, Erlangen, Germany
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Barrett NA, Hart N, Camporota L. Assessment of Work of Breathing in Patients with Acute Exacerbations of Chronic Obstructive Pulmonary Disease. COPD 2019; 16:418-428. [PMID: 31694406 DOI: 10.1080/15412555.2019.1681390] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The assessment of the work of breathing (WOB) of patients with acute exacerbations of chronic obstructive pulmonary disease (COPD) is difficult, particularly when the patient first presents with acute hypercapnia and respiratory acidosis. Acute exacerbations of COPD patients are in significant respiratory distress and noninvasive measurements of WOB are easier for the patient to tolerate. Given the interest in using alternative therapies to noninvasive ventilation, such as high flow nasal oxygen therapy or extracorporeal carbon dioxide removal, understanding the physiological changes are key and this includes assessment of WOB. This narrative review considers the role of three different methods of assessing WOB in patients with acute exacerbations of COPD. Esophageal pressure is a very well validated measure of WOB, however the ability of patients with acute exacerbations of COPD to tolerate esophageal tubes is poor. Noninvasive alternative measurements include parasternal electromyography (EMG) and electrical impedance tomography (EIT). EMG is easily applied and is a well validated measure of neural drive but is more likely to be degraded by the electrical environment in intensive care or high dependency. EIT is less well validated as a tool for WOB in COPD but extremely well tolerated by patients. Each of the different methods assess WOB in a different way and have different advantages and disadvantages. For research into therapies treating acute exacerbations of COPD, combinations of EIT, EMG and esophageal pressure are likely to be better than only one of these.
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Affiliation(s)
- N A Barrett
- Centre for Human & Applied Physiological Sciences (CHAPS), School of Basic & Medical Biosciences, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom.,Department of Critical Care, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - N Hart
- Lane Fox Respiratory Unit, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - L Camporota
- Centre for Human & Applied Physiological Sciences (CHAPS), School of Basic & Medical Biosciences, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom.,Department of Critical Care, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
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Karsten J, Voigt N, Gillmann HJ, Stueber T. Determination of optimal positive end-expiratory pressure based on respiratory compliance and electrical impedance tomography: a pilot clinical comparative trial. ACTA ACUST UNITED AC 2019; 64:135-145. [PMID: 29874190 DOI: 10.1515/bmt-2017-0103] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 05/04/2018] [Indexed: 12/16/2022]
Abstract
There is no agreement on gold standard method for positive end-expiratory pressure (PEEP) titration. Electrical impedance tomography (EIT) may aid in finding the optimal PEEP level. In this pilot trial, we investigated potential differences in the suggested optimal PEEP (BestPEEP) as derived by respiratory compliance and EIT-derived parameters. We examined if compliance-derived PEEP differs with regard to the regional ventilation distribution in relation to atelectasis and hyperinflation. Measurements were performed during an incremental/decremental PEEP trial in 15 ventilated intensive care patients suffering from mild-to-moderate impairment of oxygenation due to sepsis, pneumonia, trauma and metabolic and ischemic disorders. Measurement agreement was analyzed using Bland-Altman plots. We observed a diversity of EIT-derived and compliance-based optimal PEEP in the evaluated patients. BestPEEPCompliance did not necessarily correspond to the BestPEEPODCL with the least regional overdistension and collapse. The collapsed area was significantly smaller when the overdistension/collapse index was used for PEEP definition (p=0.022). Our results showed a clinically relevant difference in the suggested optimal PEEP levels when using different parameters for PEEP titration. The compliance-derived PEEP level revealed a higher proportion of residual regional atelectasis as compared to EIT-based PEEP.
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Affiliation(s)
- Jan Karsten
- Department of Anaesthesiology and Intensive Care Medicine, Hannover Medical School, 30625 Hannover, Germany
| | - Nicolas Voigt
- Department of Anaesthesiology and Intensive Care Medicine, Hannover Medical School, 30625 Hannover, Germany
| | - Hans-Joerg Gillmann
- Department of Anaesthesiology and Intensive Care Medicine, Hannover Medical School, 30625 Hannover, Germany
| | - Thomas Stueber
- Department of Anaesthesiology and Intensive Care Medicine, Hannover Medical School, 30625 Hannover, Germany
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Mellenthin MM, Mueller JL, de Camargo EDLB, de Moura FS, Santos TBR, Lima RG, Hamilton SJ, Muller PA, Alsaker M. The ACE1 Electrical Impedance Tomography System for Thoracic Imaging. IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT 2019; 68:3137-3150. [PMID: 33223563 PMCID: PMC7678726 DOI: 10.1109/tim.2018.2874127] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The design and performance of the ACE1 (Active Complex Electrode) electrical impedance tomography system for single-ended phasic voltage measurements is presented. The design of the hardware and calibration procedures allow for reconstruction of conductivity and permittivity images. Phase measurement is achieved with the ACE1 active electrode circuit which measures the amplitude and phase of the voltage and the applied current at the location at which current is injected into the body. An evaluation of the system performance under typical operating conditions includes details of demodulation and calibration and an in-depth look at insightful metrics, such as signal-to-noise ratio variations during a single current pattern. Static and dynamic images of conductivity and permittivity are presented from ACE1 data collected on tank phantoms and human subjects to illustrate the system's utility.
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Affiliation(s)
| | - Jennifer L Mueller
- Department of Mathematics and School of Biomedical Engineering and the Department of Electrical and Computer Engineering, Colorado State University, CO 80523 USA
| | | | - Fernando Silva de Moura
- Center for Engineering, Modeling and Applied Social Sciences, Federal University of ABC, São Paulo, Brazil
| | | | - Raul Gonzalez Lima
- Mechanical Engineering Department, University of São Paulo, São Paulo, Brazil
| | - Sarah J Hamilton
- Department of Mathematics, Statistics, and Computer Science; Marquette University, Milwaukee, WI, 53233 USA
| | - Peter A Muller
- Department of Mathematics, Colorado State University, CO 80523 USA
| | - Melody Alsaker
- Department of Mathematics, Colorado State University, Fort Collins, C0, 80523 USA
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Cereda M, Xin Y, Goffi A, Herrmann J, Kaczka DW, Kavanagh BP, Perchiazzi G, Yoshida T, Rizi RR. Imaging the Injured Lung: Mechanisms of Action and Clinical Use. Anesthesiology 2019; 131:716-749. [PMID: 30664057 PMCID: PMC6692186 DOI: 10.1097/aln.0000000000002583] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Acute respiratory distress syndrome (ARDS) consists of acute hypoxemic respiratory failure characterized by massive and heterogeneously distributed loss of lung aeration caused by diffuse inflammation and edema present in interstitial and alveolar spaces. It is defined by consensus criteria, which include diffuse infiltrates on chest imaging-either plain radiography or computed tomography. This review will summarize how imaging sciences can inform modern respiratory management of ARDS and continue to increase the understanding of the acutely injured lung. This review also describes newer imaging methodologies that are likely to inform future clinical decision-making and potentially improve outcome. For each imaging modality, this review systematically describes the underlying principles, technology involved, measurements obtained, insights gained by the technique, emerging approaches, limitations, and future developments. Finally, integrated approaches are considered whereby multimodal imaging may impact management of ARDS.
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Affiliation(s)
- Maurizio Cereda
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
| | - Yi Xin
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Alberto Goffi
- Interdepartmental Division of Critical Care Medicine and Department of Medicine, University of Toronto, ON, Canada
| | - Jacob Herrmann
- Departments of Anesthesia and Biomedical Engineering, University of Iowa, IA
| | - David W. Kaczka
- Departments of Anesthesia, Radiology, and Biomedical Engineering, University of Iowa, IA
| | | | - Gaetano Perchiazzi
- Hedenstierna Laboratory and Uppsala University Hospital, Uppsala University, Sweden
| | - Takeshi Yoshida
- Hospital for Sick Children, University of Toronto, ON, Canada
| | - Rahim R. Rizi
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
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Longhini F, Maugeri J, Andreoni C, Ronco C, Bruni A, Garofalo E, Pelaia C, Cavicchi C, Pintaudi S, Navalesi P. Electrical impedance tomography during spontaneous breathing trials and after extubation in critically ill patients at high risk for extubation failure: a multicenter observational study. Ann Intensive Care 2019; 9:88. [PMID: 31410738 PMCID: PMC6692788 DOI: 10.1186/s13613-019-0565-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 08/03/2019] [Indexed: 01/08/2023] Open
Abstract
Background This study aims to assess the changes in lung aeration and ventilation during the first spontaneous breathing trial (SBT) and after extubation in a population of patients at risk of extubation failure. Methods We included 78 invasively ventilated patients eligible for their first SBT, conducted with low positive end-expiratory pressure (2 cm H2O) for 30 min. We acquired three 5-min electrical impedance tomography (EIT) records at baseline, soon after the beginning (SBT_0) and at the end (SBT_30) of SBT. In the case of SBT failure, ventilation was reinstituted; otherwise, the patient was extubated and two additional records were acquired soon after extubation (SB_0) and 30 min later (SB_30) during spontaneous breathing. Extubation failure was defined by the onset of post-extubation respiratory failure within 48 h after extubation. We computed the changes from baseline of end-expiratory lung impedance (∆EELI), tidal volume (∆Vt%), and the inhomogeneity index. Arterial blood was sampled for gas analysis. Data were compared between sub-groups stratified for SBT and extubation success/failure. Results Compared to SBT success (n = 61), SBT failure (n = 17) showed a greater reduction in ∆EELI at SBT_0 (p < 0.001) and SBT_30 (p = 0.001) and a higher inhomogeneity index at baseline (p = 0.002), SBT_0 (p = 0.003) and SBT_30 (p = 0.005). RR/Vt was not different between groups at baseline but was significantly greater at SBT_0 and SBT_30 in SBT failures, compared to SBT successes (p < 0.001 for both). No differences in ∆Vt% and arterial blood gases were observed between SBT success and failure. The ∆Vt%, ∆EELI, inhomogeneity index and arterial blood gases were not different between patients with extubation success (n = 39) and failure (n = 22) (p > 0.05 for all comparisons). Conclusions Compared to SBT success, SBT failure was characterized by more lung de-recruitment and inhomogeneity. Whether EIT may be useful to monitor SBT remains to be determined. No significant changes in lung ventilation, aeration or homogeneity related to extubation outcome occurred up to 30 min after extubation. Trial registration Retrospectively registered on clinicaltrials.gov (Identifier: NCT03894332; release date 27th March 2019). Electronic supplementary material The online version of this article (10.1186/s13613-019-0565-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Federico Longhini
- Anesthesia and Intensive Care, Sant'Andrea Hospital, ASL VC, Vercelli, Italy
| | - Jessica Maugeri
- Anesthesia and Intensive Care, "Garibaldi Centro" Hospital, ARNAS Garibaldi, Catania, Italy
| | - Cristina Andreoni
- Anesthesia and Intensive Care, Infermi Hospital, AUSL Romagna, Rimini, Italy
| | - Chiara Ronco
- Anesthesia and Intensive Care, Sant'Andrea Hospital, ASL VC, Vercelli, Italy
| | - Andrea Bruni
- Anesthesia and Intensive Care Unit, University Hospital Mater Domini, Department of Medical and Surgical Sciences, Magna Graecia University, Viale Europa - Loc. Germaneto, 88100, Catanzaro, Italy
| | - Eugenio Garofalo
- Anesthesia and Intensive Care Unit, University Hospital Mater Domini, Department of Medical and Surgical Sciences, Magna Graecia University, Viale Europa - Loc. Germaneto, 88100, Catanzaro, Italy
| | - Corrado Pelaia
- Anesthesia and Intensive Care Unit, University Hospital Mater Domini, Department of Medical and Surgical Sciences, Magna Graecia University, Viale Europa - Loc. Germaneto, 88100, Catanzaro, Italy
| | - Camilla Cavicchi
- Anesthesia and Intensive Care, Infermi Hospital, AUSL Romagna, Rimini, Italy
| | - Sergio Pintaudi
- Anesthesia and Intensive Care, "Garibaldi Centro" Hospital, ARNAS Garibaldi, Catania, Italy
| | - Paolo Navalesi
- Anesthesia and Intensive Care Unit, University Hospital Mater Domini, Department of Medical and Surgical Sciences, Magna Graecia University, Viale Europa - Loc. Germaneto, 88100, Catanzaro, Italy.
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Barrett NA, Kostakou E, Hart N, Douiri A, Camporota L. Extracorporeal carbon dioxide removal for acute hypercapnic exacerbations of chronic obstructive pulmonary disease: study protocol for a randomised controlled trial. Trials 2019; 20:465. [PMID: 31362776 PMCID: PMC6664508 DOI: 10.1186/s13063-019-3548-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 06/29/2019] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Chronic obstructive pulmonary disease (COPD) is a common cause of chronic respiratory failure and its course is punctuated by a series of acute exacerbations which commonly lead to hospital admission. Exacerbations are managed through the application of non-invasive ventilation and, when this fails, tracheal intubation and mechanical ventilation. The need for mechanical ventilation significantly increases the risk of death. An alternative therapy, extracorporeal carbon dioxide removal (ECCO2R), has been shown to be efficacious in removing carbon dioxide from the blood; however, its impact on respiratory physiology and patient outcomes has not been explored. METHODS/DESIGN A randomised controlled open label trial of patients (12 in each arm) with acute exacerbations of COPD at risk of failing conventional therapy (NIV) randomised to either remaining on NIV or having ECCO2R added to NIV with a primary endpoint of time to cessation of NIV. The change in respiratory physiology following the application of ECCO2R and/or NIV will be measured using electrical impedance tomography, oesophageal pressure and parasternal electromyography. Additional outcomes, including patient tolerance, outcomes, need for readmission, changes in blood gases and biochemistry and procedural complications, will be measured. Physiological changes will be compared within one patient over time and between the two groups. Healthcare costs in the UK system will also be compared between the two groups. DISCUSSION COPD is a common disease and exacerbations are a leading cause of hospital admission in the UK and worldwide, with a sizeable mortality. The management of patients with COPD consumes significant hospital and financial resources. This study seeks to understand the feasibility of a novel approach to the management of patients with acute exacerbations of COPD as well as to understand the underlying physiological changes to explain why the approach does or does not assist this patient cohort. Detailed respiratory physiology has not been previously undertaken using this technique and there are no other randomised controlled trials currently in the literature. TRIAL REGISTRATION ClinicalTrials.gov, NCT02086084.
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Affiliation(s)
- Nicholas A. Barrett
- Department of Critical Care, Guy’s and St Thomas’ NHS Foundation Trust, Westminster Bridge Rd, London, SE1 7EH UK
- Centre for Human & Applied Physiological Sciences (CHAPS), School of Basic & Medical Biosciences, Faculty of Life Sciences & Medicine, King’s College London, London, UK
| | - Eirini Kostakou
- Department of Critical Care, Guy’s and St Thomas’ NHS Foundation Trust, Westminster Bridge Rd, London, SE1 7EH UK
| | - Nicholas Hart
- Centre for Human & Applied Physiological Sciences (CHAPS), School of Basic & Medical Biosciences, Faculty of Life Sciences & Medicine, King’s College London, London, UK
- Lane Fox Respiratory Unit, Guy’s and St Thomas’ NHS Foundation Trust, Westminster Bridge Rd, London, SE1 7EH UK
| | - Abdel Douiri
- School of Population Health & Environmental Sciences, King’s College London, London, WC2R 2LS UK
- National Institute for Health Research Biomedical Research Centre, Guy’s and St Thomas’ NHS Trust and King’s College London, London, UK
| | - Luigi Camporota
- Department of Critical Care, Guy’s and St Thomas’ NHS Foundation Trust, Westminster Bridge Rd, London, SE1 7EH UK
- Centre for Human & Applied Physiological Sciences (CHAPS), School of Basic & Medical Biosciences, Faculty of Life Sciences & Medicine, King’s College London, London, UK
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Tomicic V, Cornejo R. Lung monitoring with electrical impedance tomography: technical considerations and clinical applications. J Thorac Dis 2019; 11:3122-3135. [PMID: 31463141 DOI: 10.21037/jtd.2019.06.27] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In recent years there has been substantial progress in the imaging evaluation of patients with lung disease requiring mechanical ventilatory assistance. This has been demonstrated by the inclusion of pulmonary ultrasound, positron emission tomography, electrical impedance tomography (EIT), and magnetic resonance imaging (MRI). The EIT uses electric current to evaluate the distribution of alternating current conductivity within the thoracic cavity. The advantage of the latter is that it is non-invasive, bedside radiation-free functional imaging modality for continuous monitoring of lung ventilation and perfusion. EIT can detect recruitment or derecruitment, overdistension, variation of poorly ventilated lung units (silent spaces), and pendelluft phenomenon in spontaneously breathing patients. In addition, the regional expiratory time constants have been recently explored.
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Affiliation(s)
- Vinko Tomicic
- Jefe Unidad de Cuidados Intensivos Respiratorios, Clínica Indisa, Universidad Andres Bello, Santiago, Chile
| | - Rodrigo Cornejo
- Jefe Unidad de Pacientes Críticos, Departamento de Medicina, Hospital Clínico Universidad de Chile, Chile
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Victor M, Melo J, Roldán R, Nakamura M, Tucci M, Costa E, Amato M, Yoneyama T, Tanaka H. Modelling approach to obtain regional respiratory mechanics using electrical impedance tomography and volume-dependent elastance model. Physiol Meas 2019; 40:045001. [PMID: 30921784 DOI: 10.1088/1361-6579/ab144a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE This paper presents a method for breath-by-breath estimation of regional respiratory mechanics without the need for special manoeuvres (such as inspiratory pause or low-flow inflation) using electrical impedance tomography (EIT) associated with pressure/airflow waveforms. APPROACH We developed a method to estimate regional parameters using the regional impedance fraction, by multiplying it by global flow and volume waveforms. A volume-dependent elastance model was used to obtain compliance, resistance, volume-independent (E 1), and volume-dependent (E 2) components. Three swine under invasive mechanical ventilation were used to assess internal consistency and illustrate potential applications of our method. One animal (case 1) was ventilated with a broad range of tidal volumes to compare the consistency between regional and global resistances and compliances. Two other animals (cases 2 and 3) had respiratory compliance decreased, respectively, by overdistension and collapse as quantified by x-ray computed tomography. MAIN RESULTS In case 1, derived global estimates obtained from the independent regional estimates were strongly associated with direct measurements of global mechanics (correlation coefficients of 0.9976 and 0.9981 for compliances and resistances, respectively), suggesting consistency of our modelling. In cases 2 and 3, the development of lung overdistension and collapse over time was captured by regional estimates. CONCLUSIONS Using EIT and pressure/airflow waveforms, regional respiratory parameters can be obtained cycle-by-cycle, refining lung function monitoring. SIGNIFICANCE The method allows real-time monitoring of regional parameters and their trends over time, which might be helpful to differentiate deterioration in lung compliance due to overdistension or collapse.
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Affiliation(s)
- M Victor
- Electronics Engineering Department, Aeronautics Institute of Technology, São Paulo, Brazil
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Vasques F, Sanderson B, Barrett NA, Camporota L. Monitoring of regional lung ventilation using electrical impedance tomography. Minerva Anestesiol 2019; 85:1231-1241. [PMID: 30945516 DOI: 10.23736/s0375-9393.19.13477-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Among recent lung imaging techniques and devices, electrical impedance tomography (EIT) can provide dynamic information on the distribution regional lung ventilation. EIT images possess a high temporal and functional resolution allowing the visualization of dynamic physiological and pathological changes on a breath-by-breath basis. EIT detects changes in electric impedance (i.e., changes in gas/fluid ratio) and describes them in real time, both visually through images and waveforms, and numerically, allowing the clinician to monitor disease evolution and response to treatment. The use of EIT in clinical practice is supported by several studies demonstrating a good correlation between impedance tomography data and other validated methods of measuring lung volume. In this review, we will provide an overview on the rationale, basic functioning and most common applications of EIT in the management of mechanically ventilated patients.
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Affiliation(s)
- Francesco Vasques
- Department of Adult Critical Care, Guy's and St Thomas' NHS Foundation Trust, King's Health Partners, London, UK.,Division of Centre of Human Applied Physiological Sciences, King's College London, London, UK
| | - Barnaby Sanderson
- Department of Adult Critical Care, Guy's and St Thomas' NHS Foundation Trust, King's Health Partners, London, UK.,Division of Centre of Human Applied Physiological Sciences, King's College London, London, UK
| | - Nicholas A Barrett
- Department of Adult Critical Care, Guy's and St Thomas' NHS Foundation Trust, King's Health Partners, London, UK.,Division of Centre of Human Applied Physiological Sciences, King's College London, London, UK
| | - Luigi Camporota
- Department of Adult Critical Care, Guy's and St Thomas' NHS Foundation Trust, King's Health Partners, London, UK - .,Division of Centre of Human Applied Physiological Sciences, King's College London, London, UK
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Bachmann MC, Morais C, Bugedo G, Bruhn A, Morales A, Borges JB, Costa E, Retamal J. Electrical impedance tomography in acute respiratory distress syndrome. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2018; 22:263. [PMID: 30360753 PMCID: PMC6203288 DOI: 10.1186/s13054-018-2195-6] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 09/14/2018] [Indexed: 12/29/2022]
Abstract
Acute respiratory distress syndrome (ARDS) is a clinical entity that acutely affects the lung parenchyma, and is characterized by diffuse alveolar damage and increased pulmonary vascular permeability. Currently, computed tomography (CT) is commonly used for classifying and prognosticating ARDS. However, performing this examination in critically ill patients is complex, due to the need to transfer these patients to the CT room. Fortunately, new technologies have been developed that allow the monitoring of patients at the bedside. Electrical impedance tomography (EIT) is a monitoring tool that allows one to evaluate at the bedside the distribution of pulmonary ventilation continuously, in real time, and which has proven to be useful in optimizing mechanical ventilation parameters in critically ill patients. Several clinical applications of EIT have been developed during the last years and the technique has been generating increasing interest among researchers. However, among clinicians, there is still a lack of knowledge regarding the technical principles of EIT and potential applications in ARDS patients. The aim of this review is to present the characteristics, technical concepts, and clinical applications of EIT, which may allow better monitoring of lung function during ARDS.
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Affiliation(s)
- M Consuelo Bachmann
- Departamento de Medicina Intensiva, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Acute Respiratory and Critical Illness Center (ARCI), Santiago, Chile
| | - Caio Morais
- Divisao de Pneumologia, Instituto do Coracao (Incor), Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Guillermo Bugedo
- Departamento de Medicina Intensiva, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Acute Respiratory and Critical Illness Center (ARCI), Santiago, Chile
| | - Alejandro Bruhn
- Departamento de Medicina Intensiva, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Acute Respiratory and Critical Illness Center (ARCI), Santiago, Chile
| | - Arturo Morales
- Departamento Enfermedades Respiratorias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - João B Borges
- Divisao de Pneumologia, Instituto do Coracao (Incor), Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.,Hedenstierna Laboratory, Department of Surgical Sciences, Section of Anaesthesiology and Critical Care, Uppsala University, Uppsala, Sweden
| | - Eduardo Costa
- Divisao de Pneumologia, Instituto do Coracao (Incor), Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Jaime Retamal
- Departamento de Medicina Intensiva, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile. .,Acute Respiratory and Critical Illness Center (ARCI), Santiago, Chile.
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Karagiannidis C, Waldmann AD, Róka PL, Schreiber T, Strassmann S, Windisch W, Böhm SH. Regional expiratory time constants in severe respiratory failure estimated by electrical impedance tomography: a feasibility study. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2018; 22:221. [PMID: 30236123 PMCID: PMC6148957 DOI: 10.1186/s13054-018-2137-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 07/27/2018] [Indexed: 01/17/2023]
Abstract
Background Electrical impedance tomography (EIT) has been used to guide mechanical ventilation in ICU patients with lung collapse. Its use in patients with obstructive pulmonary diseases has been rare since obstructions could not be monitored on a regional level at the bedside. The current study therefore determines breath-by-breath regional expiratory time constants in intubated patients with chronic obstructive pulmonary disease (COPD) and acute respiratory distress syndrome (ARDS). Methods Expiratory time constants calculated from the global impedance EIT signal were compared to the pneumatic volume signals measured with an electronic pneumotachograph. EIT-derived expiratory time constants were additionally determined on a regional and pixelwise level. However, regional EIT signals on a single pixel level could in principle not be compared with similar pneumatic changes since these measurements cannot be obtained in patients. For this study, EIT measurements were conducted in 14 intubated patients (mean Simplified Acute Physiology Score II (SAPS II) 35 ± 10, mean time on invasive mechanical ventilation 36 ± 26 days) under four different positive end-expiratory pressure (PEEP) levels ranging from 10 to 17 cmH2O. Only patients with moderate-severe ARDS or COPD exacerbation were included into the study, preferentally within the first days following intubation. Results Spearman’s correlation coefficient for comparison between EIT-derived time constants and those from flow/volume curves was between 0.78 for tau (τ) calculated from the global impedance signal up to 0.83 for the mean of all pixelwise calculated regional impedance changes over the entire PEEP range. Furthermore, Bland-Altman analysis revealed a corresponding bias of 0.02 and 0.14 s within the limits of agreement ranging from − 0.50 to 0.65 s for the aforementioned calculation methods. In addition, exemplarily in patients with moderate-severe ARDS or COPD exacerbation, different PEEP levels were shown to have an influence on the distribution pattern of regional time constants. Conclusions EIT-based determination of breath-by-breath regional expiratory time constants is technically feasible, reliable and valid in invasively ventilated patients with severe respiratory failure and provides a promising tool to individually adjust mechanical ventilation in response to the patterns of regional airflow obstruction. Trial registration German Trial Register DRKS 00011650, registered 01/31/17. Electronic supplementary material The online version of this article (10.1186/s13054-018-2137-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Christian Karagiannidis
- Department of Pneumology and Critical Care Medicine, Cologne-Merheim Hospital, Kliniken der Stadt Köln gGmbH, Witten/Herdecke University Hospital, Ostmerheimer Strasse 200, D-51109, Cologne, Germany.
| | - Andreas D Waldmann
- Department of Pneumology and Critical Care Medicine, Cologne-Merheim Hospital, Kliniken der Stadt Köln gGmbH, Witten/Herdecke University Hospital, Ostmerheimer Strasse 200, D-51109, Cologne, Germany.,Swisstom AG, Schulstrasse 1, 7302, Landquart, Switzerland
| | - Péter L Róka
- Budapest University of Technology and Economics, Budapest, Hungary
| | - Tina Schreiber
- Department of Pneumology and Critical Care Medicine, Cologne-Merheim Hospital, Kliniken der Stadt Köln gGmbH, Witten/Herdecke University Hospital, Ostmerheimer Strasse 200, D-51109, Cologne, Germany
| | - Stephan Strassmann
- Department of Pneumology and Critical Care Medicine, Cologne-Merheim Hospital, Kliniken der Stadt Köln gGmbH, Witten/Herdecke University Hospital, Ostmerheimer Strasse 200, D-51109, Cologne, Germany
| | - Wolfram Windisch
- Department of Pneumology and Critical Care Medicine, Cologne-Merheim Hospital, Kliniken der Stadt Köln gGmbH, Witten/Herdecke University Hospital, Ostmerheimer Strasse 200, D-51109, Cologne, Germany
| | - Stephan H Böhm
- Klinik und Poliklinik für Anästhesiologie und Intensivtherapie, Universitätsmedizin Rostock, Schillingallee 35, D-18057, Rostock, Germany
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Muller PA, Mueller JL, Mellenthin M, Murthy R, Capps M, Wagner BD, Alsaker M, Deterding R, Sagel SD, Hoppe J. Evaluation of surrogate measures of pulmonary function derived from electrical impedance tomography data in children with cystic fibrosis. Physiol Meas 2018; 39:045008. [PMID: 29565263 DOI: 10.1088/1361-6579/aab8c4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Lung function monitoring by spirometry plays a critical role in the clinical care of pediatric cystic fibrosis (CF) patients, but many young children are unable to perform spirometry, and the outputs are often normal even in the presence of lung disease. Measures derived from electrical impedance tomography (EIT) images were studied for their utility as potential surrogates for spirometry in CF patients and to assess response to intravenous antibiotic treatment for acute pulmonary exacerbations (PEx) in a subset of patients. APPROACH EIT data were collected on 35 subjects (21 with CF, 14 healthy controls, 8 CF patients pre- and post-treatment for an acute PEx) ages 2 to 20 years during tidal breathing and also concurrently with spirometry on subjects over age 8. EIT-derived measures of FEV1, FVC, and FEV1/FVC were computed globally and regionally from dynamic EIT images. MAIN RESULTS Global EIT-derived FEV1/FVC showed good correlation with spirometry FEV1/FVC values (r = 0.54, p = 0.01), and were able to distinguish between the groups (p = 0.01). Lung heterogeneity was assessed through the spatial coefficient of variation (CV) of EIT difference images between key time points, and the CVs for EIT-derived FEV1 and FVC showed significant correlation with the CV for tidal breathing (r = 0.47, p = 0.01 and r = 0.50, p = 0.01, respectively). Global EIT-derived FEV1/FVC was better able to distinguish between groups than spirometry FEV1 (F-values 776.5 and 146.3, respectively, p < 0.01.) The same held true for the CVs for EIT-derived FEV1, FVC, and tidal breathing (F-values 215.93, 193.89, 204.57, respectively, p < 0.01). SIGNIFICANCE The strong correlation between the CVs for tidal breathing, FEV1, and FVC, and the statistically significant ability of CV for tidal breathing to distinguish between healthy subjects and CF patients, and between the studied CF disease states suggests that the CV may be useful for measuring the extent and severity of structural lung disease.
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Affiliation(s)
- Peter A Muller
- Department of Mathematics & Statistics, Villanova University, PA, United States of America. was at Department of Mathematics, Colorado State University, CO, United States of America
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da Silva Ramos FJ, Hovnanian A, Souza R, Azevedo LCP, Amato MBP, Costa ELV. Estimation of Stroke Volume and Stroke Volume Changes by Electrical Impedance Tomography. Anesth Analg 2018; 126:102-110. [PMID: 28742775 DOI: 10.1213/ane.0000000000002271] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Electrical impedance tomography (EIT) is a noninvasive imaging method that identifies changes in air and blood volume based on thoracic impedance changes. Recently, there has been growing interest in EIT to measure stroke volume (SV). The objectives of this study are as follows: (1) to evaluate the ability of systolic impedance variations (ΔZsys) to track changes in SV in relation to a baseline condition; (2) to assess the relationship of ΔZsys and SV in experimental subjects; and (3) to identify the influence of body dimensions on the relationship between ΔZsys and SV. METHODS Twelve Agroceres pigs were instrumented with transpulmonary thermodilution catheter and EIT and were mechanically ventilated in a random order using different settings of tidal volume (VT) and positive end-expiratory pressure (PEEP): VT 10 mL·kg and PEEP 10 cm H2O, VT 10 mL·kg and PEEP 5 cm H2O, VT 6 mL·kg and PEEP 10 cm H2O, and VT 6 mL·kg and PEEP 5 cm H2O. After baseline data collection, subjects were submitted to hemorrhagic shock and successive fluid challenges. RESULTS A total of 204 paired measurements of SV and ΔZsys were obtained. The 4-quadrant plot showed acceptable trending ability with a concordance rate of 91.2%. Changes in ΔZsys after fluid challenges presented an area under the curve of 0.83 (95% confidence interval, 0.74-0.92) to evaluate SV changes. Conversely, the linear association between ΔZsys and SV was poor, with R from linear mixed model of 0.35. Adding information on body dimensions improved the linear association between ΔZsys and SV up to R from linear mixed model of 0.85. CONCLUSIONS EIT showed good trending ability and is a promising hemodynamic monitoring tool. Measurements of absolute SV require that body dimensions be taken into account.
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Affiliation(s)
- Fernando José da Silva Ramos
- From the Department of Intensive Care and Anesthesiology Research Laboratory, Research and Education Institute, Hospital Sírio-Libanês, São Paulo, Brazil
| | - André Hovnanian
- From the Department of Intensive Care and Anesthesiology Research Laboratory, Research and Education Institute, Hospital Sírio-Libanês, São Paulo, Brazil.,Respiratory Intensive Care Unit, University of São Paulo School of Medicine, São Paulo, Brazil
| | - Rogério Souza
- Respiratory Intensive Care Unit, University of São Paulo School of Medicine, São Paulo, Brazil
| | - Luciano C P Azevedo
- From the Department of Intensive Care and Anesthesiology Research Laboratory, Research and Education Institute, Hospital Sírio-Libanês, São Paulo, Brazil
| | - Marcelo B P Amato
- Respiratory Intensive Care Unit, University of São Paulo School of Medicine, São Paulo, Brazil
| | - Eduardo L V Costa
- From the Department of Intensive Care and Anesthesiology Research Laboratory, Research and Education Institute, Hospital Sírio-Libanês, São Paulo, Brazil.,Respiratory Intensive Care Unit, University of São Paulo School of Medicine, São Paulo, Brazil
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46
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Lobo B, Hermosa C, Abella A, Gordo F. Electrical impedance tomography. ANNALS OF TRANSLATIONAL MEDICINE 2018; 6:26. [PMID: 29430443 PMCID: PMC5799136 DOI: 10.21037/atm.2017.12.06] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2017] [Accepted: 11/30/2017] [Indexed: 11/06/2022]
Abstract
Continuous assessment of respiratory status is one of the cornerstones of modern intensive care unit (ICU) monitoring systems. Electrical impedance tomography (EIT), although with some constraints, may play the lead as a new diagnostic and guiding tool for an adequate optimization of mechanical ventilation in critically ill patients. EIT may assist in defining mechanical ventilation settings, assess distribution of tidal volume and of end-expiratory lung volume (EELV) and contribute to titrate positive end-expiratory pressure (PEEP)/tidal volume combinations. It may also quantify gains (recruitment) and losses (overdistention or derecruitment), granting a more realistic evaluation of different ventilator modes or recruitment maneuvers, and helping in the identification of responders and non-responders to such maneuvers. Moreover, EIT also contributes to the management of life-threatening lung diseases such as pneumothorax, and aids in guiding fluid management in the critical care setting. Lastly, assessment of cardiac function and lung perfusion through electrical impedance is on the way.
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Affiliation(s)
- Beatriz Lobo
- Intensive Care Unit, Henares University Hospital, Coslada-Madrid, Spain
- Grupo de Investigación en Patología Crítica, Facultad de Ciencias de la Salud, Universidad Francisco de Vitoria, Pozuelo de Alarcón, Madrid, Spain
| | - Cecilia Hermosa
- Intensive Care Unit, Henares University Hospital, Coslada-Madrid, Spain
- Grupo de Investigación en Patología Crítica, Facultad de Ciencias de la Salud, Universidad Francisco de Vitoria, Pozuelo de Alarcón, Madrid, Spain
| | - Ana Abella
- Intensive Care Unit, Henares University Hospital, Coslada-Madrid, Spain
- Grupo de Investigación en Patología Crítica, Facultad de Ciencias de la Salud, Universidad Francisco de Vitoria, Pozuelo de Alarcón, Madrid, Spain
| | - Federico Gordo
- Intensive Care Unit, Henares University Hospital, Coslada-Madrid, Spain
- Grupo de Investigación en Patología Crítica, Facultad de Ciencias de la Salud, Universidad Francisco de Vitoria, Pozuelo de Alarcón, Madrid, Spain
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48
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Ambrisko TD, Schramel JP, Auer U, Moens YPS. Impact of four different recumbencies on the distribution of ventilation in conscious or anaesthetized spontaneously breathing beagle dogs: An electrical impedance tomography study. PLoS One 2017; 12:e0183340. [PMID: 28922361 PMCID: PMC5603158 DOI: 10.1371/journal.pone.0183340] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 08/02/2017] [Indexed: 11/18/2022] Open
Abstract
The aim was to examine the effects of recumbency and anaesthesia on distribution of ventilation in beagle dogs using Electrical Impedance Tomography (EIT). Nine healthy beagle dogs, aging 3.7±1.7 (mean±SD) years and weighing 16.3±1.6 kg, received a series of treatments in a fixed order on a single occasion. Conscious dogs were positioned in right lateral recumbency (RLR) and equipped with 32 EIT electrodes around the thorax. Following five minutes of equilibration, two minutes of EIT recordings were made in each recumbency in the following order: RLR, dorsal (DR), left (LLR) and sternal (SR). The dogs were then positioned in RLR, premedicated (medetomidine 0.01, midazolam 0.1, butorphanol 0.1 mg kg-1 iv) and pre-oxygenated. Fifteen minutes later anaesthesia was induced with 1 mg kg-1 propofol iv and maintained with propofol infusion (0.1–0.2 mg kg-1 minute-1 iv). After induction, the animals were intubated and allowed to breathe spontaneously (FIO2 = 1). Recordings of EIT were performed again in four recumbencies similarly to conscious state. Centre of ventilation (COV) and global inhomogeneity (GI) index were calculated from the functional EIT images. Repeated-measures ANOVA and Bonferroni tests were used for statistical analysis (p < 0.05). None of the variables changed in the conscious state. During anaesthesia left-to-right COV increased from 46.8±2.8% in DR to 49.8±2.9% in SR indicating a right shift, and ventral-to-dorsal COV increased from 49.8±1.7% in DR to 51.8±1.1% in LLR indicating a dorsal shift in distribution of ventilation. Recumbency affected distribution of ventilation in anaesthetized but not in conscious dogs. This can be related to loss of respiratory muscle tone (e.g. diaphragm) and changes in thoracic shape. Changing position of thoraco-abdominal organs under the EIT belt should be considered as alternative explanation of these findings.
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Affiliation(s)
- Tamas D Ambrisko
- Anaesthesiology and Perioperative Intensive-Care Medicine, Department for Companion Animals and Horses, University of Veterinary Medicine, Vienna, Austria
| | - Johannes P Schramel
- Anaesthesiology and Perioperative Intensive-Care Medicine, Department for Companion Animals and Horses, University of Veterinary Medicine, Vienna, Austria
| | - Ulrike Auer
- Anaesthesiology and Perioperative Intensive-Care Medicine, Department for Companion Animals and Horses, University of Veterinary Medicine, Vienna, Austria
| | - Yves P S Moens
- Anaesthesiology and Perioperative Intensive-Care Medicine, Department for Companion Animals and Horses, University of Veterinary Medicine, Vienna, Austria
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Ball L, Vercesi V, Costantino F, Chandrapatham K, Pelosi P. Lung imaging: how to get better look inside the lung. ANNALS OF TRANSLATIONAL MEDICINE 2017; 5:294. [PMID: 28828369 DOI: 10.21037/atm.2017.07.20] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In the last years, imaging has played a key role in the diagnosis and monitoring and critical illness, including acute respiratory distress syndrome (ARDS). Chest X-ray (CXR) and computed tomography (CT) are the conventional techniques most performed in the critically ill patients, the latter being the gold standard to assess lung aeration in ARDS patients. In addition, two bedside techniques are now gaining popularity alongside the conventional ones: lung ultrasound (LUS) and electrical impedance tomography (EIT). These techniques do not involve the use of ionizing radiations, are non-invasive and relatively easy to use, and are under extensive investigation as a complement, and for some application a substitution of conventional techniques. At last, positron emission tomography (PET) and magnetic resonance imaging (MRI) can provide functional information on the lung and respiratory function, and are increasingly used in research to improve the understanding of the pathophysiological mechanisms underlying ARDS. The purpose of this review is to give an up-to-date overview of the conventional and emerging imaging techniques available the diagnosis and management of patients with ARDS.
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Affiliation(s)
- Lorenzo Ball
- Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Ospedale Policlinico San Martino-IRCCS per l'Oncologia, Genoa, Italy
| | - Veronica Vercesi
- Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Ospedale Policlinico San Martino-IRCCS per l'Oncologia, Genoa, Italy
| | - Federico Costantino
- Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Ospedale Policlinico San Martino-IRCCS per l'Oncologia, Genoa, Italy
| | - Karthikka Chandrapatham
- Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Ospedale Policlinico San Martino-IRCCS per l'Oncologia, Genoa, Italy
| | - Paolo Pelosi
- Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Ospedale Policlinico San Martino-IRCCS per l'Oncologia, Genoa, Italy
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Caruana LR, Barnett AG, Tronstad O, Paratz JD, Chang AT, Fraser JF. Global tidal variations, regional distribution of ventilation, and the regional onset of filling determined by electrical impedance tomography: reproducibility. Anaesth Intensive Care 2017; 45:235-243. [PMID: 28267946 DOI: 10.1177/0310057x1704500214] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The reproducibility of the regional distribution of ventilation and the timing of onset of regional filling as measured by electrical impedance tomography lacks evidence. This study investigated whether electrical impedance tomography measurements in healthy males were reproducible when electrodes were replaced between measurements. Part 1: Recordings of five volunteers lying supine were made using electrical impedance tomography and a pneumotachometer. Measurements were repeated at least three hours later. Skin marking ensured accurate replacement of electrodes. No stabilisation period was allowed. Part 2: Electrical impedance tomography recordings of ten volunteers; a 15 minute stabilisation period, extra skin markings, and time-averaging were incorporated to improve the reproducibility. Reproducibility was determined using the Bland-Altman method. To judge the transferability of the limits of agreement, a Pearson correlation was used for electrical impedance tomography tidal variation and tidal volume. Tidal variation was judged to be reproducible due to the significant correlation between tidal variation and tidal volume (r2 = 0.93). The ventilation distribution was not reproducible. A stabilisation period, extra skin markings and time-averaging did not improve the outcome. The timing of regional onset of filling was reproducible and could prove clinically valuable. The reproducibility of the tidal variation indicates that non-reproducibility of the ventilation distribution was probably a biological difference and not measurement error. Other causes of variability such as electrode placement variability or lack of stabilisation when accounted for did not improve the reproducibility of the ventilation distribution.
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Affiliation(s)
- L R Caruana
- Physiotherapist, The Critical Care Research Group, The Prince Charles Hospital, The University of Queensland School of Medicine, Brisbane, Queensland
| | - A G Barnett
- Associate Professor, The Critical Care Research Group, The Prince Charles Hospital, School of Public Health & Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland
| | - O Tronstad
- Clinical Lead Physiotherapist, The Critical Care Research Group, The Prince Charles Hospital, Brisbane, Queensland
| | - J D Paratz
- Physiotherapist, The Critical Care Research Group, The Prince Charles Hospital, Burns, Trauma and Critical Research Centre, School of Medicine, University of Queensland, Brisbane, Griffith University, Southport, Queensland
| | - A T Chang
- Physiotherapist, The Critical Care Research Group, The Prince Charles Hospital, School of Health and Rehabilitation Sciences, University of Queensland, Brisbane, Queensland
| | - J F Fraser
- Director, The Critical Care Research Group, The Prince Charles Hospital, Professor, School of Health and Rehabilitation Sciences, University of Queensland, Brisbane, Queensland
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