Dynamic relative regional strain visualized by electrical impedance tomography in patients suffering from COVID-19

AbstractRespiratory failure due to SARS-CoV-2 may progress rapidly. During the course of COVID-19, patients develop an increased respiratory drive, which may induce high mechanical strain a known risk factor for Patient Self-Inflicted Lung Injury (P-SILI). We developed a novel Electrical Impedance Tomography-based approach to visualize the Dynamic Relative Regional Strain (DRRS) in SARS-CoV-2 positive patients and compared these findings with measurements in lung healthy volunteers. DRRS was defined as the ratio of tidal impedance changes and end-expiratory lung impedance within each pixel of the lung region. DRRS values of the ten patients were considerably higher than those of the ten healthy volunteers. On repeated examination, patterns, magnitude and frequency distribution of DRRS were reproducible and in line with the clinical course of the patients. Lung ultrasound scores correlated with the number of pixels showing DRRS values above the derived threshold. Using Electrical Impedance Tomography we were able to generate, for the first time, images of DRRS which might indicate P-SILI in patients suffering from COVID-19.Trial Registration This observational study was registered 06.04.2020 in German Clinical Trials Register (DRKS00021276).

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Evaluation of electrical impedance tomography for determination of urinary bladder volume: comparison with standard ultrasound methods in healthy volunteers

BioMedical Engineering OnLine ◽

10.1186/s12938-018-0526-0 ◽

2018 ◽

Vol 17 (1) ◽

Cited By ~ 5

Author(s):

Dorothea Leonhäuser ◽

Carlos Castelar ◽

Thomas Schlebusch ◽

Martin Rohm ◽

Rüdiger Rupp ◽

...

Keyword(s):

Urinary Bladder ◽

Healthy Volunteers ◽

Electrical Impedance Tomography ◽

Electrical Impedance ◽

Bladder Volume ◽

Impedance Tomography ◽

Volume Comparison

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Electrical impedance tomography and trans-pulmonary pressure measurements in a patient with extreme respiratory drive

Respiratory Medicine Case Reports ◽

10.1016/j.rmcr.2017.01.008 ◽

2017 ◽

Vol 20 ◽

pp. 141-144

Author(s):

Atsuko Shono ◽

Peter Somhorst ◽

Diederik Gommers

Keyword(s):

Electrical Impedance Tomography ◽

Electrical Impedance ◽

Respiratory Drive ◽

Pressure Measurements ◽

Impedance Tomography ◽

Pulmonary Pressure

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Non-invasive pulmonary artery pressure estimation by electrical impedance tomography in a controlled hypoxemia study in healthy subjects

Scientific Reports ◽

10.1038/s41598-020-78535-4 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Martin Proença ◽

Fabian Braun ◽

Mathieu Lemay ◽

Josep Solà ◽

Andy Adler ◽

...

Keyword(s):

Pulmonary Hypertension ◽

Pulmonary Artery ◽

Healthy Volunteers ◽

Correlation Coefficient ◽

Electrical Impedance Tomography ◽

Pulmonary Artery Pressure ◽

Electrical Impedance ◽

Impedance Tomography ◽

Artery Pressure ◽

Non Invasive

AbstractPulmonary hypertension is a hemodynamic disorder defined by an abnormal elevation of pulmonary artery pressure (PAP). Current options for measuring PAP are limited in clinical practice. The aim of this study was to evaluate if electrical impedance tomography (EIT), a radiation-free and non-invasive monitoring technique, can be used for the continuous, unsupervised and safe monitoring of PAP. In 30 healthy volunteers we induced gradual increases in systolic PAP (SPAP) by exposure to normobaric hypoxemia. At various stages of the protocol, the SPAP of the subjects was estimated by transthoracic echocardiography. In parallel, in the pulmonary vasculature, pulse wave velocity was estimated by EIT and calibrated to pressure units. Within-cohort agreement between both methods on SPAP estimation was assessed through Bland–Altman analysis and at subject level, with Pearson’s correlation coefficient. There was good agreement between the two methods (inter-method difference not significant (P > 0.05), bias ± standard deviation of − 0.1 ± 4.5 mmHg) independently of the degree of PAP, from baseline oxygen saturation levels to profound hypoxemia. At subject level, the median per-subject agreement was 0.7 ± 3.8 mmHg and Pearson’s correlation coefficient 0.87 (P < 0.05). Our results demonstrate the feasibility of accurately assessing changes in SPAP by EIT in healthy volunteers. If confirmed in a patient population, the non-invasive and unsupervised day-to-day monitoring of SPAP could facilitate the clinical management of patients with pulmonary hypertension.

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