Clinical Research Directory

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.

Cyclic On-off Switching of Pulmonary Blood Flow in Moderate to Severe ARDS

Although the theoretical model of "cyclic on-off switching of pulmonary blood flow" provides a crucial perspective for understanding VILI, its clinical validation and real-time intervention face significant obstacles. The fundamental reason lies in the lack of pulmonary microcirculation monitoring technology capable of bedside, non-invasive, continuous operation with sufficient spatiotemporal resolution. Nowadays, a novel 3D-EIT can perform real-time and non-invasive assessment of the distribution of pulmonary blood flow. However, if 3D-EIT can help to identify "cyclic on-off switching of pulmonary blood flow" is still unclear.