A Pilot Trial of Pressure Muscle Index-Targeted PSV Trial

Pressure support ventilation (PSV) is one of the most frequently used ventilator modes in the intensive care unit (ICU). The successful implementation of PSV depends on matching the patient's inspiratory effort with the ventilator support. In clinical practice, the pressure support level is usually set and adjusted according to tidal volume (VT) and respiratory rate (RR). However, these parameters may not fully represent the patient's effort. Previous studies have shown that pressure muscle index (PMI), which is measured as the difference between the peak and plateau airway pressure during an end-inspiratory airway occlusion, could reliably determine the low and high inspiratory effort during PSV. However, the comparative effectiveness of these two pressure support level setting strategies remains uncertain. Our aim is to explore clinical and implementation factors relevant to a future definitive randomized controlled trial to evaluate PMI - and VT/RR - pressure support level setting strategies. The Inspiratory effort-targeted pressure support ventilation pragmatic pilot trial will test clinician adherence and to explore clinical outcomes. Two centers are included in a pragmatic sequential cluster crossover pilot trial. We enrolled all eligible adults with acute respiratory failure requiring mechanical ventilation admitted to ICU. The pressure support level setting strategy was assigned according to the epoch. The first trial epoch will be assigned to VTRR - pressure support level setting strategy for 4 weeks. The washout week between the two epochs will be 4 weeks. Then sequentially, it will be crossed over to PMI - pressure support level setting strategy for 4 weeks. * In the VT/RR-targeted group, the pressure support is adjusted to obtain a VT between 6 and 8 ml/kg PBW and RR between 20 and 35 breaths/min until day 28 or death or performance of spontaneous breathing trial (SBT). * In the PMI-targeted group, the pressure support is adjusted according to PMI between 0 and 2 cmH2O until day 28 or death or performance of SBT. We will also survey clinicians to understand potential facilitators and barriers to conducting a definitive randomized trial.