The Efficacy of Oscillation and Lung Expansion (OLE) Therapy Evaluated by Compterized Tomography (CT) and Electrical Impedance Tomography（EIT）in Prolonged Mechanical Ventilated Patients With Atelectasis: A Multicenter Randomized Contralled Trial

High frequency chest wall oscillation (HFCWO) is currently one of the most common and widespread mechanical airway clearance techniques (ACTs) in clinical practice in China. As an external airway oscillation technique, it has been proven in previous clinical practices that it can help clear secretions by vibrating the chest wall, loosening the secretions adhering to the airway walls and promoting ciliary movement, thereby improving lung ventilation and re-expansion. However, there are still some groups of patients for whom this technique is not suitable in clinical practice, such as those who are uncomfortable with the oscillation, have damaged skin on the chest and back, have unstable rib fractures, or have poorly positioned tracheostomy tubes. In recent years, integrating multiple techniques into a single treatment has become a trend. Among them, oscillation and lung expansion (OLE) combines continuous positive airway pressure (CPAP), continuous high-frequency oscillation (CHFO), and nebulization, which can effectively clear airway secretions and promote lung re-expansion. Currently, only a few studies have confirmed that OLE has a positive impact on improving respiratory function in patients with acute respiratory failure, severe burns, and after lung surgery.

This study aims to further compare the effects of the above two mechanical ACTs on improving lung ventilation and re-expansion by electrical impedance tomography (EIT), and optimize the clinical practice of physical therapists.