Electrical Impedance Tomography-Guided Identification of the Optimal Lateral Position in Postoperative ARDS

This prospective, randomized crossover physiological study evaluates the effects of lateral positioning (left lateral position and right lateral position) versus the supine position on ventilation-perfusion (V/Q) matching in adult postoperative abdominal surgery participants with acute respiratory distress syndrome (ARDS). Bedside electrical impedance tomography (EIT) will be used to quantify regional ventilation and perfusion (perfusion derived from an intravenous tracer bolus administered during a brief breath-hold) and to calculate global "normal V/Q" (normal V/Q, %). Oxygenation, respiratory mechanics (when applicable), and hemodynamics will be recorded concurrently. Feasibility and safety of the positioning protocol will also be assessed.

NCT Number	NCT07669558
Lead Sponsor	Ruijin Hospital
Conditions	Acute Respiratory Distress Syndrome (ARDS), Postoperative
Enrollment	22 participants
Start Date	2026-06-28
Primary Completion	2026-10-31 (estimated)
Study Completion	2026-10-31 (estimated)
Updated on ClinicalTrials.gov	2026-08-03