Proportional Assist Ventilation for Minimizing the Duration of Mechanical Ventilation

PROMIZING

PURPOSE

The primary purpose of the PROMIZING Study is to determine whether initiating PAV+ early in the recovery phase of acute respiratory failure shortens the time to successful liberation from invasive mechanical ventilation compared with PSV. Secondary aims evaluate whether PAV+ improves additional clinical outcomes such as ICU stay, hospital stay, weaning success, complications, and mortality.

PROGRESS

100%

patients enrolled

FUTURE

PROMIZING is designed to provide the first large, definitive evidence on whether PAV+ should replace PSV as the standard assisted ventilation mode during recovery. Its results may help optimize weaning practices, reduce mechanical ventilation complications, and inform international guidelines on ventilatory support strategies in critically ill adults. The trial’s large, diverse, multicentre design ensures its findings will be broadly applicable across ICUs worldwide.

What is PROMIZING?

The PROMIZING Study is a large, international, multicentre randomized controlled trial evaluating whether Proportional Assist Ventilation (PAV+) shortens the duration of invasive mechanical ventilation compared with standard Pressure Support Ventilation (PSV) in adults recovering from acute respiratory failure. PAV+ adjusts ventilatory support proportionally to patient effort, while PSV provides a fixed level of assistance. The trial targets patients transitioning from full ventilator support into the recovery phase who are not yet ready for extubation.

Why is this important?

Prolonged mechanical ventilation can cause respiratory muscle weakness, ventilator‑induced diaphragm atrophy, patient–ventilator asynchrony, and heavy sedation use — all of which delay weaning and increase complications, ICU length of stay, and mortality. By maintaining patient respiratory muscle activity and improving synchrony, PAV+ may accelerate recovery, reduce time on the ventilator, and improve broader clinical outcomes. The study aims to determine whether these physiologic advantages translate into meaningful improvements in liberation from ventilation and patient survival.

What is involved in the study?

Participants who meet all staged eligibility criteria proceed through screening, a pressure support trial, and spontaneous breathing assessments before randomization. They are then assigned to either PAV+ or PSV, with ventilator settings adjusted according to detailed algorithms specific to each study arm. Patients are followed daily until successful liberation from ventilation, ICU discharge, hospital discharge, death, or 90 days after randomization. Outcomes measured include ventilator‑free days, weaning progress, complications, sedative exposure, and mortality at multiple time points.

Study Arms

Intervention Arm: Proportional Assist Ventilation (PAV+)

In the PAV+ arm, participants receive ventilation using Proportional Assist Ventilation with load‑adjustable gain factors, delivered exclusively on a Puritan Bennett 840 or 980 ventilator. PAV+ provides assistance proportional to the patient’s own breathing effort, continuously adjusting support based on real‑time measurements of resistance and compliance. This allows clinicians to target a defined range of respiratory muscle activity (Pmus 5–10 cmH₂O), helping maintain diaphragm engagement while avoiding excessive workload. Settings—including gain, PEEP, and FiO₂—are titrated according to a detailed algorithm that responds to respiratory distress, gas exchange, and pH. Patients are assessed at least every eight hours to ensure support is optimized, and may be temporarily switched to assist‑control ventilation if instability develops.

Control Arm: Pressure Support Ventilation (PSV)

In the PSV arm, participants receive standard of care Pressure Support Ventilation, delivered on any ventilator capable of providing pressure support. Unlike PAV+, PSV provides a fixed level of assistance for each breath, adjusted based on clinical parameters such as respiratory rate, tidal volume, comfort, and gas exchange. The PSV algorithm guides clinicians in titrating support to maintain a respiratory rate between 12–35 breaths per minute and a tidal volume of 5–10 mL/kg predicted body weight, while ensuring adequate oxygenation and pH. Adjustments are made at least every eight hours, and if respiratory distress or clinical instability occurs—such as intolerance of PS >20 cmH₂O or PS+PEEP >30 cmH₂O—patients are transitioned to assist‑control ventilation and reassessed for return to PSV when stable.