Abstract:Objective: Patients with the novel coronavirus disease (COVID-19) often have airway secretions that severely compromise ventilation. This study investigates electrical impedance tomography (EIT) monitoring of a therapeutic bronchoalveolar lavage (BAL) in a patient with COVID-19. Approach: A patient with COVID-19 developed acute respiratory distress syndrome requiring mechanical ventilation. He received regional BAL to remove mucus in the small airways (20 ml × 5). Regional ventilation changes before BAL, 30 mi… Show more
“…The resulting voltages and reconstructed regional impedance values reflect the volume changes of air and blood in the lung tissue (2). Chest EIT applications cover a broad field of clinical practice (3), including the treatment of acute respiratory distress syndrome (ARDS) (4), coronavirus disease 2019 (5)(6)(7), and acute exacerbation of chronic obstructive pulmonary disease under mechanical ventilation (8,9), as well as pulmonary function testing for patients with asthma, cystic fibrosis, and chronic obstructive pulmonary disease (10)(11)(12)(13).…”
Background: Although electrical impedance tomography (EIT) is widely used for monitoring regional ventilation distribution, reference values have yet to be established for clinical use. The present study aimed to evaluate the feasibility of creating reference values for standard EIT parameters for potential clinical application.Methods: A total of 75 participants with healthy lungs were included in this prospective study (male:female, 48:27; age, 34±14 years; height, 172±7 cm; weight, 73±12 kg). The subjects were examined during spontaneous breathing in the supine position. EIT measurements were performed at the level of the 4 th intercostal space. Commonly used EIT-based parameters, including the center of ventilation (CoV), dorsal and most dorsal fractions of ventilation distribution (TV D and TV ROI4 respectively), global inhomogeneity (GI) index, and standard deviation of regional ventilation delay index (RVD SD ) were calculated.Results: Following outlier detection, EIT data from 71 subjects were finally evaluated. The values of the evaluated parameters were: CoV, 48.7%±1.7%; TVD, 48.1%±5.4%; TV ROI4 , 7.1%±1.8%; GI, 0.49±0.04; and RVD SD , 7.0±2.0. The coefficients of variation for CoV and GI were low (0.03 and 0.07, respectively), but those for TV ROI4 and RVD SD were comparatively high (0.26 and 0.28, respectively). None of the evaluated parameters showed a significant correlation with age. The GI index showed a weak but significant correlation with body mass index (R=0.29, P=0.01). The RVD SD was slightly higher in males than in females.Conclusions: Our study indicated that CoV and GI were stable parameters with small coefficients of variation in participants with healthy lungs. The creation of EIT parameter reference values for setting treatment targets may be feasible.
“…The resulting voltages and reconstructed regional impedance values reflect the volume changes of air and blood in the lung tissue (2). Chest EIT applications cover a broad field of clinical practice (3), including the treatment of acute respiratory distress syndrome (ARDS) (4), coronavirus disease 2019 (5)(6)(7), and acute exacerbation of chronic obstructive pulmonary disease under mechanical ventilation (8,9), as well as pulmonary function testing for patients with asthma, cystic fibrosis, and chronic obstructive pulmonary disease (10)(11)(12)(13).…”
Background: Although electrical impedance tomography (EIT) is widely used for monitoring regional ventilation distribution, reference values have yet to be established for clinical use. The present study aimed to evaluate the feasibility of creating reference values for standard EIT parameters for potential clinical application.Methods: A total of 75 participants with healthy lungs were included in this prospective study (male:female, 48:27; age, 34±14 years; height, 172±7 cm; weight, 73±12 kg). The subjects were examined during spontaneous breathing in the supine position. EIT measurements were performed at the level of the 4 th intercostal space. Commonly used EIT-based parameters, including the center of ventilation (CoV), dorsal and most dorsal fractions of ventilation distribution (TV D and TV ROI4 respectively), global inhomogeneity (GI) index, and standard deviation of regional ventilation delay index (RVD SD ) were calculated.Results: Following outlier detection, EIT data from 71 subjects were finally evaluated. The values of the evaluated parameters were: CoV, 48.7%±1.7%; TVD, 48.1%±5.4%; TV ROI4 , 7.1%±1.8%; GI, 0.49±0.04; and RVD SD , 7.0±2.0. The coefficients of variation for CoV and GI were low (0.03 and 0.07, respectively), but those for TV ROI4 and RVD SD were comparatively high (0.26 and 0.28, respectively). None of the evaluated parameters showed a significant correlation with age. The GI index showed a weak but significant correlation with body mass index (R=0.29, P=0.01). The RVD SD was slightly higher in males than in females.Conclusions: Our study indicated that CoV and GI were stable parameters with small coefficients of variation in participants with healthy lungs. The creation of EIT parameter reference values for setting treatment targets may be feasible.
“…Therapeutic bronchoalveolar lavage removes mucus in the small airways and improves regional ventilation. EIT was found useful at the bedside to monitor the ventilation treatment and anticoagulant treatment in COVID-19 [ 14 , 46 ]. Fig.…”
Section: Imaging Modalitiesmentioning
confidence: 99%
“…HRCT (slice thickness: 0.625-1.25 mm) and U-HRCT (slice thickness: 0.2-0.5 mm) in which thin-slice chest images are acquired and reconstructed using a sharp algorithm are outstanding imaging tools to access blood volume and vasculature abnormalities in COVID-19 without contrast agents. In some longitudinal studies, HRCT detects early lung injury and evaluates disease severity, clinical typing, type of lesions, and post-treatment follow-up [13][14][15][16][17]. U-HRCT scanner observed superiority over HRCT in detecting not only distribution and lesions of COVID-19 but also imaging local lung volume loss [18,19].…”
Section: High-resolution Ct (Hrct) and Ultra-hrct (U-hrct)mentioning
COVID-19 hypoxemic patients although sharing a same etiology (SARS-CoV-2 infection) present themselves quite differently from one another. Patients also respond differently to prescribed medicine and to prone Vs supine bed positions. A severe pulmonary ventilation-perfusion mismatch usually triggers moderate to severe COVID-19 cases. Imaging can aid the physician in assessing severity of COVID-19. Although useful for their portability X-ray and ultrasound serving on the frontline to evaluate lung parenchymal abnormalities are unable to provide information about pulmonary vasculature and blood flow redistribution which is a consequence of hypoxemia in COVID-19. Advanced imaging modalities such as computed tomography, single-photon emission tomography, and electrical impedance tomography use a sharp algorithm visualizing pulmonary ventilation-perfusion mismatch in the abnormal and in the apparently normal parenchyma. Imaging helps to access the severity of infection, lung performance, ventilation-perfusion mismatch, and informs strategies for medical treatment. This review summarizes the capacity of these imaging modalities to assess ventilation-perfusion mismatch in COVID-19. Despite having limitations, these modalities provide vital information on blood volume distribution, pulmonary embolism, pulmonary vasculature and are useful to assess severity of lung disease and effectiveness of treatment in COVID-19 patients.
“…EIT could provide variation of conductivity distribution for lung during the breathing process [19], [20]. Compared with traditional medical imaging techniques, EIT is a non-invasive, bedside radiation-free imaging modality and could continuously monitor lung function [21]- [26]. As a dynamic medical imaging technique, it is an ideal and promising method to monitor lung movements.…”
Motion tracking is an effective approach for the management of respiratory motion during the medical imaging process, which has always been a major concern in diagnostic imaging, interventional, and non-invasive therapy. However, the low imaging speed of traditional medical imaging techniques limits the practical application of real-time motion tracking. Electrical impedance tomography (EIT) is proved to be an effective tool for continuous monitoring of lung activity/status. However, the respiratory motion has never been studied in the medical EIT field before. In this paper, preliminary research of lung movement during the respiratory process is first studied based on EIT. Multi-ring electrode thorax models under different respiratory statuses were constructed to obtain simulation data of EIT. A modified TV algorithm is used for the estimation of lung volume and movement based on 3D EIT images, which improve the quality of reconstruction by approximately 30% and 20% compared with the traditional Tikhonov method and the total variation (TV) method, respectively. Both simulations and experiments were conducted to show the potential of respiratory motion tracking through 3D EIT reconstruction.
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