Lung Recruitment During Chest Physiotherapy in Mechanically Ventilated Patients

It is hypothesized that the effectiveness of respiratory physiotherapy on recruitment depends on the ventilatory mode used during the session. The primary objective is to compare pulmonary recruitment during respiratory physiotherapy in patients under invasive mechanical ventilation between sessions performed in V-ACV and PSV. Secondary objectives are to compare the effects of respiratory physiotherapy between V-ACV mode and PSV mode on respiratory mechanics, gas exchange, the amount of drained secretions (weight and volume), the distribution of ventilation, and patient tolerance. Method: A cross-over study with a non-invasive physiological endpoint. The primary evaluation criterion is variations in end-expiratory lung volume (ΔEELV) measured 5 minutes before and 5 minutes after a standardized respiratory physiotherapy session in V-ACV or PSV. The tool used to measure End Expiratory Lung Volume (EELV) is the additional module E-sCOVX of the CARESCAPE R860 ventilator. The procedure is automated and is based on a dilution method. Secondary outcomes aim to evaluate regional lung ventilation distribution, respiratory mechanics, airway clearance, gas exchange, and patient tolerance. Tools used to measure secondary evaluation criteria include Electrical Impedance Tomography (EIT) Pulmovista 500® (Dräger), a Pneumotachograph with a pressure transducer inserted in the ventilator circuit (MP150, Biopac Systems, Inc.), and a trap to collect mucus. The intervention consists of a standardized session in a standardized position (supine at 35° of head elevation). Each session is composed of 7 series of 3 Rib Cage Compressions (RCC) in a row during each expiration, applied to the thorax only. The interval between the series is about 10 respiratory cycles. The 2 sessions are done on the same day. One session is performed in the morning, the other in the afternoon. One session is performed in V-ACV and the other in PSV. The order is randomized. Conclusion: The results of this study will help better understand the effects of RCC according to the ventilatory mode in patients under invasive mechanical ventilation with mucus excess.