Effect of Three Modalities of Spontaneous Breathing Tests on Respiratory Efforts in Tracheostomized Patients

Effect of Three Modalities of Spontaneous Breathing Tests on Respiratory Efforts in Tracheostomized Patients. Monocentric Crossover Interventionnal Study.

Datas are lacking concerning weaning from mechanical ventilation for tracheostomized patients. In particular, the effect of different modalities of spontaneous breathing trials on respiratory effort has not been extensively described.

This crossover physiology study will include 18 tracheostomized patients ventilated for more than 72 hours.

The objective of this study is to compare the effect of three different modalities of SBTs on respiratory effort in tracheostomized patients. The modalities tested are : Pressure Support Ventilation (PSV level 5 cmH2O, PEEP 5 cmH2O), T-piece test and high-flow Oxygen. Each modality is applied in a randomized order, during 30 minutes. During every modality tested, esophageal and gastric pressure, expired CO2, and comfort will be monitored, in addition to standard monitoring. Based on esophageal pressure monitoring, patient's respiratory efforts can be calculated either by esophageal pressure-time product and work of breathing. Pressure generated by inspiratory muscles will also be assessed.

Inclusion Criteria:

• Patients for whom a tracheostomy is planned
• Patients on invasive ventilation for >72 hours

Exclusion Criteria:

• Tracheostomy for upper airway obstruction or other disease
• Patients tracheostomized before current hospitalization
• Patients with Glasgow Coma Scale (GCS) < 8/10 after cardiac arrest
• Patients with GCS < 8/10 because of primary central neurologic disease
• Patients for whom therapeutic limitations have already been decided
• Patients for whom weaning from ventilation is not an objective
• Patients suffering from myasthenia gravis
• Patients with cardiac assistance device
• Patients with medullary lesion proximal to C5
• Patients for whom nasogastric tube insertion is contraindicated