Study on How Different PEEP Levels Affect Breathing Effort in Adults with Acute Hypoxemic Respiratory Failure on Mechanical Ventilation

What this Trial Is About

Researchers are studying patients with acute hypoxemic respiratory failure AHRF who require invasive mechanical ventilation. This study aims to understand how different levels of positive end-expiratory pressure PEEP affect the diaphragms neuromechanical efficiency, which reflects neural respiratory drive and inspiratory effort. The study also seeks to identify the main factors influencing PEEP-related changes in diaphragm function, lung mechanics, and muscle activity. The study involves testing six different PEEP levels 15, 12, 10, 8, 5, and 2 cmH2O in a decreasing sequence during a trial. Each PEEP level is maintained for 30 minutes, with measurements taken during the last 10 minutes of each step. Researchers will collect data on respiratory muscle function using ultrasound and surface electromyography, lung inflation patterns through electrical impedance tomography, muscle activity, gas exchange, and hemodynamic parameters. Participants will be adults on invasive assisted mechanical ventilation in pressure support mode with adequate inspiratory effort. Throughout the study, multiple assessments will be performed at each PEEP level, including diaphragm thickening fraction, expiratory muscle activity, gastric pressure, and various respiratory mechanics. The primary outcome is the change in diaphragm neuromechanical efficiency, while secondary outcomes include changes in inspiratory effort, neural respiratory drive, lung mechanics, and gas exchange. The total participation time varies per patient as measurements are taken during the PEEP trial steps.

PEEP-induced Effects on Respiratory dRivE and EFfort