Effect of thoracic fluid content on electrical impedance tomography (EIT) measurements

UMIN ID: UMIN000054238

Registered date:23/04/2024

Basic Information

• Recruitment status: Recruiting
• Health condition(s) or Problem(s) studied: non
• Date of first enrollment: 2024/04/23
• Target sample size: 10
• Countries of recruitment: Japan
• Study type: Interventional
• Intervention(s): 1. measurement will be performed in the anesthesiologist's office 2. The time required is about 1 hour (including breaks). (including a break) 3. recruitment of subjects will be open to the public. 4. recruitment will be open to healthy healthcare professionals and medical students. Recruitment will be open to healthy healthcare professionals and medical students, and recruitment information will be posted in the anesthesiologist's office and surrounding corridors. 5. a supine healthy adult will be fitted with an electrical impedance tomography (EIT) measurement belt; 6. a flow sensor will be connected to the EIT belt; 7. the EIT belt will be attached to the anesthesiologist's chest A face mask with a flow sensor attached will be placed on the subject, and spontaneous breathing will be induced to simultaneously measure respiratory parameters such as airway pressure, flow rate, and ventilation rate, as well as impedance using EIT. 7. In the actual measurement procedure, the subject is first placed in the supine position and normal breathing is measured. 8. Next, after elevation of both lower extremities, the same measurements are taken. 9. Next, after both lower limbs have been raised, the patient is placed in the supine position and normal breathing is measured. 10. Next, while in the supine position, connect an external resistor with a 3 mm inner diameter slit to the end of the flow sensor and perform the same measurements. 11. Next, remove the external resistor and perform a normal breath measurement. 12. Then, while the patient is in the supine position, perform a normal breath measurement. Next, while in the supine position, connect an external resistor with a slit of 2 mm inner diameter to the end of the flow sensor and perform the same measurement. 13. Finally, the external resistor is disconnected and a normal breath is measured.

Outcome(s)

• Primary Outcome: This study is a prospective, before-and-after comparative study. The primary objective of this study was to verify whether the impedance values measured by EIT change accordingly when the amount of fluid in the thoracic cavity is increased. Interventions to increase intrathoracic fluid content will include generating negative pressure in the thoracic cavity through a combination of inspiratory effort and flow restriction, and through positional changes (standing, supine, and elevated lower extremities). After measuring baseline parameters (ventilatory output, airway pressure, flow, resistance, and impedance using EIT) with a ventilometer, techniques to increase intrapleural fluid volume (increasing intrapleural negative pressure with inspiratory effort and flow restriction, or changing body position) are performed on the subject, and baseline parameters are measured as in the baseline procedure. parameters as at baseline. Pre- and post-intervention comparisons will test the hypothesis that increased intrathoracic fluid content will increase the impedance value measured by EIT. Corresponding t-tests or Wilcoxon's signed rank sum test will be used for pre- and post-intervention comparisons of parameters, and correlation analysis will be used to examine the relationship between intrathoracic pressure (substituted by airway pressure due to the difficulty of directly measuring it) and impedance values.

Key inclusion & exclusion criteria

• Age minimum: 18years-old
• Age maximum: Not applicable
• Gender: Male and Female
• Exclude criteria: Patients with pre-existing respiratory disease. Patients with pre-existing cardiovascular disease. Patients with pre-existing neuromuscular disease.

Related Information

• Primary Sponsor: Tohoku University
• Source(s) of Monetary Support: Tohoku University