Non-apnea Electrical Impedance Tomography for Bedside Ventilation-Perfusion Assessment: a Prospective Cross-over Validation Study

Title: Validating the Accuracy of Lung Blood Flow Monitoring Without Breath-Holding Under Spontaneous Breathing Support Purpose: The purpose of this study is to evaluate the accuracy of a new Electrical Impedance Tomography (EIT) technique that measures lung blood flow (perfusion) without requiring patients to hold their breath. We aim to determine if this "non-apnea" method provides results consistent with the current clinical gold standard (the "pause" method). Background: EIT is a non-invasive bedside tool used to monitor lung function. The traditional method for measuring lung blood flow requires patients to hold their breath for 5-8 seconds during a saline injection to avoid interference from breathing. However, many patients-especially those using a nasal cannula, high-flow nasal oxygen (HFNO), or pressure support ventilation (PSV)-must maintain continuous spontaneous breathing and find it difficult or unsafe to hold their breath. If a "non-apnea" method is proven accurate, it will make monitoring safer and easier for these patients. What the Study Involves: The study includes stable adult patients who are breathing spontaneously. Each patient undergoes two measurements in a randomized order: Standard Reference (Pause Method): Measurement taken during a brief, guided breath-hold. Test Method (Non-Apnea Method): Measurement taken during normal, uninterrupted breathing while receiving respiratory support (Nasal Cannula, HFNO, or PSV). Expected Significance: By comparing the lung images and ventilation/perfusion (V/Q) data from both methods, this study seeks to validate the reliability and precision of the non-apnea approach. This would allow clinicians to assess lung health in spontaneously breathing patients without interrupting their natural breathing rhythm.

NCT Number	NCT07489950
Lead Sponsor	Ruijin Hospital
Conditions	Pulmonary Perfusion, Ventilation-Perfusion Ratio, Respiratory Insufficiency, Critical Illness
Enrollment	24 participants
Start Date	2026-03-19
Primary Completion	2026-04-13 (estimated)
Study Completion	2026-04-13 (estimated)
Updated on ClinicalTrials.gov	2026-04-23