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

Abstract

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.

Effect of Prone Positioning With Individualized Positive End-Expiratory Pressure in Acute Respiratory Distress Syndrome Using Electrical Impedance Tomography

“…Electrical impedance tomography (EIT) as a non-invasive, radiation-free imaging tool that has received great interest in the respiratory management of critically ill patients ( Sella et al, 2021 ). EIT generates cross-sectional images of the impedance distribution within the thorax and measures continuously regional lung volume changes at the bedside ( Hinz et al, 2003 ; Kotani et al, 2016 ; Aguirre-Bermeo et al, 2018 ; Holanda et al, 2018 ). EIT is widely used in lung ventilation assessment in hypoxemia patients, including the PEEP titration (Dalla Corte et al, 2020 ; He et al, 2021 ; He et al, 2020 ; Yun et al, 2016 ; Becher et al, 2021 ; Gibot et al, 2021 ; Muders et al, 2021 ; Scaramuzzo et al, 2020b ).…”