scholarly journals Helping students to understand physiological aspects of regional distribution of ventilation in humans: a experience from the electrical impedance tomography

2018 ◽  
Vol 42 (4) ◽  
pp. 655-660
Author(s):  
Marcelo Alcantara Holanda ◽  
Nathalia Parente de Sousa ◽  
Luana Torres Melo ◽  
Liégina Silveira Marinho ◽  
Helder Veras Ribeiro-Filho ◽  
...  
Keyword(s):  
Medical Students ◽  
Electrical Impedance ◽  
Respiratory Mechanics ◽  
Pulmonary Ventilation ◽  
Regional Distribution ◽  
Lung Ventilation ◽  
Respiratory Physiology ◽  
Impedance Tomography ◽  
Lateral Decubitus ◽  
Basic Concepts

Undergraduate biomedical students often have difficulties in understanding basic concepts of respiratory physiology, particularly respiratory mechanics. In this study, we report the use of electrical impedance tomography (EIT) to improve and consolidate the knowledge about physiological aspects of normal regional distribution of ventilation in humans. Initially, we assessed the previous knowledge of a group of medical students ( n = 39) about regional differences in lung ventilation. Thereafter, we recorded the regional distribution of ventilation through surface electrodes on a healthy volunteer adopting four different decubitus positions: supine, prone, and right and left lateral. The recordings clearly showed greater pulmonary ventilation in the dependent lung, mainly in the lateral decubitus. Considering the differences in pulmonary ventilation between right and left lateral decubitus, only 33% of students were able to notice it correctly beforehand. This percentage increased to 84 and 100%, respectively ( P < 0.01), after the results of the ventilation measurements obtained with EIT were examined and discussed. A self-assessment questionnaire showed that students considered the practical activity as an important tool to assist in the understanding of the basic concepts of respiratory mechanics. Experimental demonstration of the physiological variations of regional lung ventilation in volunteers by using EIT is feasible, effective, and stimulating for undergraduate medical students. Therefore, this practical activity may help faculty and students to overcome the challenges in the field of respiratory physiology learning.

Combined effects of body positioning and noninvasive ventilation on the regional distribution of pulmonary ventilation evaluated by electrical impedance tomography in the young and the elderly

2019 ◽  
Author(s):  
Liegina Silveira Marinho ◽  
Andrea Nobrega Cirino Nogueira Da Nobrega Cirino Nogueira ◽  
Juliana Arcanjo Lino ◽  
Gabriela De Carvalho Gomes Frota ◽  
Renata Dos Santos Vasconcelos ◽  
...  
Keyword(s):  
Electrical Impedance Tomography ◽  
Noninvasive Ventilation ◽  
Electrical Impedance ◽  
Pulmonary Ventilation ◽  
Regional Distribution ◽  
The Elderly ◽  
Combined Effects ◽  
Impedance Tomography ◽  
Body Positioning

scholarly journals Evaluation of Regional Pulmonary Ventilation in Spontaneously Breathing Patients with Idiopathic Pulmonary Fibrosis (IPF) Employing Electrical Impedance Tomography (EIT): A Pilot Study from the European IPF Registry (eurIPFreg)

2021 ◽  
Vol 10 (2) ◽  
pp. 192
Author(s):  
Ekaterina Krauss ◽  
Daniel van der Beck ◽  
Isabel Schmalz ◽  
Jochen Wilhelm ◽  
Silke Tello ◽  
...  
Keyword(s):  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Electrical Impedance Tomography ◽  
Spontaneous Breathing ◽  
Electrical Impedance ◽  
Statistical Significance ◽  
Pulmonary Ventilation ◽  
Healthy Controls ◽  
Impedance Tomography ◽  
Spontaneously Breathing

Objectives: In idiopathic pulmonary fibrosis (IPF), alterations in the pulmonary surfactant system result in an increased alveolar surface tension and favor repetitive alveolar collapse. This study aimed to assess the usefulness of electrical impedance tomography (EIT) in characterization of regional ventilation in IPF. Materials and methods: We investigated 17 patients with IPF and 15 healthy controls from the University of Giessen and Marburg Lung Center (UGMLC), Germany, for differences in the following EIT parameters: distribution of ventilation (TID), global inhomogeneity index (GI), regional impedance differences through the delta of end-expiratory lung impedance (dEELI), differences in surface of ventilated area (SURF), as well as center of ventilation (CG) and intratidal gas distribution (ITV). These parameters were assessed under spontaneous breathing and following a predefined escalation protocol of the positive end-expiratory pressure (PEEP), applied through a face mask by an intensive care respirator (EVITA, Draeger, Germany). Results: Individual slopes of dEELI over the PEEP increment protocol were found to be highly significantly increased in both groups (p < 0.001) but were not found to be significantly different between groups. Similarly, dTID slopes were increasing in response to PEEP, but this did not reach statistical significance within or between groups. Individual breathing patterns were very heterogeneous. There were no relevant differences of SURF, GI or CGVD over the PEEP escalation range. A correlation of dEELI to FVC, BMI, age, or weight did not forward significant results. Conclusions: In this study, we did see a significant increase in dEELI and a non-significant increase in dTID in IPF patients as well as in healthy controls in response to an increase of PEEP under spontaneous breathing. We propose the combined measurements of EIT and lung function to assess regional lung ventilation in spontaneously breathing subjects.

scholarly journals Assessment of regional lung ventilation by electrical impedance tomography in a patient with unilateral bronchial stenosis and a history of tuberculosis

2013 ◽  
Vol 39 (6) ◽  
pp. 742-746 ◽  
Author(s):  
Liégina Silveira Marinho ◽  
Nathalia Parente de Sousa ◽  
Carlos Augusto Barbosa da Silveira Barros ◽  
Marcelo Silveira Matias ◽  
Luana Torres Monteiro ◽  
...  
Keyword(s):  
Radionuclide Imaging ◽  
Electrical Impedance ◽  
Imaging Technique ◽  
Lung Ventilation ◽  
Bronchial Stenosis ◽  
Impedance Tomography ◽  
Postural Changes ◽  
Regional Lung ◽  
History Of ◽  
Regional Lung Ventilation

Bronchial stenosis can impair regional lung ventilation by causing abnormal, asymmetric airflow limitation. Electrical impedance tomography (EIT) is an imaging technique that allows the assessment of regional lung ventilation and therefore complements the functional assessment of the lungs. We report the case of a patient with left unilateral bronchial stenosis and a history of tuberculosis, in whom regional lung ventilation was assessed by EIT. The EIT results were compared with those obtained by ventilation/perfusion radionuclide imaging. The patient was using nasal continuous positive airway pressure (CPAP) for the treatment of obstructive sleep apnea syndrome. Therefore, we studied the effects of postural changes and of the use of nasal CPAP. The EIT revealed heterogeneous distribution of regional lung ventilation, the ventilation being higher in the right lung, and this distribution was influenced by postural changes and CPAP use. The EIT assessment of regional lung ventilation produced results similar to those obtained with the radionuclide imaging technique and had the advantage of providing a dynamic evaluation without radiation exposure.

Pulmonary Effects of Sustained Periods of High-G Acceleration Relevant to Suborbital Spaceflight

2021 ◽  
Vol 92 (8) ◽  
pp. 633-641
Author(s):  
Ross D. Pollock ◽  
Caroline J. Jolley ◽  
Nadia Abid ◽  
John H. Couper ◽  
Luis Estrada-Petrocelli ◽  
...  
Keyword(s):  
Work Of Breathing ◽  
Arterial Oxygen Saturation ◽  
Regional Distribution ◽  
Blood Gases ◽  
Respiratory Physiology ◽  
Arterial Oxygen ◽  
Relative Distribution ◽  
Respiratory Drive ◽  
Impedance Tomography ◽  
Arterial Blood

AbstractBACKGROUND: Members of the public will soon be taking commercial suborbital spaceflights with significant Gx (chest-to-back) acceleration potentially reaching up to 6 Gx. Pulmonary physiology is gravity-dependent and is likely to be affected, which may have clinical implications for medically susceptible individuals.METHODS: During 2-min centrifuge exposures ranging up to 6 Gx, 11 healthy subjects were studied using advanced respiratory techniques. These sustained exposures were intended to allow characterization of the underlying pulmonary response and did not replicate actual suborbital G profiles. Regional distribution of ventilation in the lungs was determined using electrical impedance tomography. Neural respiratory drive (from diaphragm electromyography) and work of breathing (from transdiaphragmatic pressures) were obtained via nasoesophageal catheters. Arterial blood gases were measured in a subset of subjects. Measurements were conducted while breathing air and breathing 15 oxygen to simulate anticipated cabin pressurization conditions.RESULTS: Acceleration caused hypoxemia that worsened with increasing magnitude and duration of Gx. Minimum arterial oxygen saturation at 6 Gx was 86 1 breathing air and 79 1 breathing 15 oxygen. With increasing Gx the alveolar-arterial (A-a) oxygen gradient widened progressively and the relative distribution of ventilation reversed from posterior to anterior lung regions with substantial gas-trapping anteriorly. Severe breathlessness accompanied large progressive increases in work of breathing and neural respiratory drive.DISCUSSION: Sustained high-G acceleration at magnitudes relevant to suborbital flight profoundly affects respiratory physiology. These effects may become clinically important in the most medically susceptible passengers, in whom the potential role of centrifuge-based preflight evaluation requires further investigation.Pollock RD, Jolley CJ, Abid N, Couper JH, Estrada-Petrocelli L, Hodkinson PD, Leonhardt S, Mago-Elliott S, Menden T, Rafferty G, Richmond G, Robbins PA, Ritchie GAD, Segal MJ, Stevenson AT, Tank HD, Smith TG. Pulmonary effects of sustained periods of high-G acceleration relevant to suborbital spaceflight. Aerosp Med Hum Perform. 2021; 92(7):633641.

Monitoring Regional Lung Ventilation by Functional Electrical Impedance Tomography during Assisted Ventilationa

1999 ◽  
Vol 873 (1 ELECTRICAL BI) ◽  
pp. 493-505 ◽  
Author(s):  
INEZ FRERICHS ◽  
GNTER HAHN ◽  
HOLGER SCHIFFMANN ◽  
CORD BERGER ◽  
GERHARD HELLIGE
Keyword(s):  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Lung Ventilation ◽  
Impedance Tomography ◽  
Regional Lung ◽  
Regional Lung Ventilation

scholarly journals Electrical Impedance Tomography for Confirmation of Lung Isolation during One-lung Ventilation

2018 ◽  
Vol 129 (3) ◽  
pp. 580-580 ◽  
Author(s):  
Gunther Hempel ◽  
Gero Schulze ◽  
Hubert Wirtz ◽  
Hermann Wrigge
Keyword(s):  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Lung Ventilation ◽  
One Lung Ventilation ◽  
Impedance Tomography ◽  
Lung Isolation
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