An interventional study of PEEP Level Adjustment in Mechanical Ventilation, Respiratory Failure and Effort, sponsored by Pontificia Universidad Catolica de Chile. Recruiting at 1 site in Chile. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-02-27.
Sponsored by Pontificia Universidad Catolica de Chile · Not applicable, Interventional, and Other
Assisted mechanical ventilation is widely used to preserve diaphragmatic activity and improve lung aeration in patients with acute respiratory failure. However, during assisted ventilation, excessive inspiratory effort may develop and contribute to lung injury, diaphragmatic overload, and patient self-inflicted lung injury.
Optimizing ventilator settings to modulate respiratory effort therefore represents a major physiological and clinical challenge.
Positive end-expiratory pressure (PEEP) is a key determinant of lung recruitment and respiratory system mechanics and may influence inspiratory effort by modifying lung volume, compliance, and respiratory drive. Despite its widespread use, PEEP titration in clinical practice is still mainly guided by oxygenation parameters, while its direct effects on inspiratory effort during assisted mechanical ventilation remain insufficiently characterized.
This physiological randomized crossover study aims to evaluate the effect of four predefined levels of positive end-expiratory pressure (0, 5, 10, and 15 cmH₂O) on the respiratory system and inspiratory effort in adult patients receiving assisted mechanical ventilation. Patients will be exposed to each PEEP level in randomized order, with stabilization and washout periods between conditions, while ventilatory support settings other than PEEP are kept constant.
1,650 studies on the registry are indexed under Respiratory Insufficiency; 296 are open to participants now.
This study's planned enrollment of 12 is below the median of 55 across 1,043 interventional studies indexed under Respiratory Insufficiency.
Browse Respiratory Insufficiency studies →Pontificia Universidad Catolica de Chile is the lead sponsor of 215 studies on the registry; 56 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Participants are ventilated with a positive end-expiratory pressure of 0 cmH₂O during assisted mechanical ventilation. Physiological measurements of respiratory effort are obtained during a predefined stabilization period according to the study protocol.
Other: PEEP Level Adjustment
Participants are ventilated with a positive end-expiratory pressure of 5 cmH₂O during assisted mechanical ventilation. Physiological measurements of respiratory effort are obtained during a predefined stabilization period according to the study protocol.
Other: PEEP Level Adjustment
Participants are ventilated with a positive end-expiratory pressure of 10 cmH₂O during assisted mechanical ventilation. Physiological measurements of respiratory effort are obtained during a predefined stabilization period according to the study protocol.
Other: PEEP Level Adjustment
Participants are ventilated with a positive end-expiratory pressure of 15 cmH₂O during assisted mechanical ventilation. Physiological measurements of respiratory effort are obtained during a predefined stabilization period according to the study protocol.
Other: PEEP Level Adjustment
Positive end-expiratory pressure (PEEP) will be adjusted to four predefined levels (0, 5, 10, and 15 cmH₂O) following a randomized crossover protocol during assisted mechanical ventilation. Only the PEEP level will be modified, while all other ventilator settings will be kept constant. Each PEEP level will be maintained for 15 minutes, followed by a 15-minute washout period between levels. Physiological measurements will be obtained during the last 5 minutes of each PEEP level, including respiratory effort assessed using invasive and non-invasive methods, respiratory mechanics, and hemodynamic parameters.
Also known as: PEEP levels
Esophageal pressure swing (ΔPes)
Esophageal pressure swing (ΔPes), defined as the absolute difference between end-expiratory and end-inspiratory esophageal pressure, measured using an esophageal balloon catheter.
Time frame: During the last 5 minutes of each PEEP level
Pressure-time product per minute (PTPmin)
Pressure-time product per minute (PTPmin), expressed as cmH₂O·s/min, measured using an esophageal balloon catheter as an index of global inspiratory effort.
Time frame: During the last 5 minutes of each PEEP level
Delta Pocc (ΔPocc)
Airway occlusion pressure-derived index (ΔPocc) obtained from brief ventilator-based airway occlusion maneuvers as a non-invasive measurement of inspiratory effort.
Time frame: During the last 5 minutes of each PEEP level
Muscular Pressure Index (PMI)
Muscular Pressure Index (PMI) calculated from ventilator-based airway occlusion maneuvers as a non-invasive estimate of inspiratory muscle pressure.
Time frame: During the last 5 minutes of each PEEP level
Airway occlusion pressure at 100 ms (P0.1)
Airway occlusion pressure at 100 milliseconds (P0.1), measured by the mechanical ventilator as an index of respiratory drive.
Time frame: During the last 5 minutes of each PEEP level
Respiratory system compliance (Cest)
Static compliance of the respiratory system (Cest) measured during assisted mechanical ventilation at each PEEP level.
Time frame: During the last 5 minutes of each PEEP level
Driving pressure
Driving pressure calculated as the difference between airway plateau pressure and total PEEP during assisted mechanical ventilation at each PEEP level.
Time frame: During the last 5 minutes of each PEEP level
Plateau pressure
Airway plateau pressure measured during assisted mechanical ventilation at each PEEP level.
Time frame: During the last 5 minutes of each PEEP level
Hemodynamic response
Hemodynamic response assessed using heart rate, arterial blood pressure, respiratory rate and oxygen saturation during assisted mechanical ventilation at different PEEP levels.
Time frame: During the last 5 minutes of each PEEP level
Gas exchange (SaFi index)
Gas exchange assessed using the SaFi index (SpO₂/FiO₂ ratio) at each PEEP level.
Time frame: During the last 5 minutes of each PEEP level
Dynamic transpulmonary pressure
ynamic transpulmonary pressure calculated during assisted mechanical ventilation using airway pressure and esophageal pressure measurements obtained with an esophageal balloon catheter.
Time frame: During the last 5 minutes of each PEEP level
Plan to share: No
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Pontificia Universidad Catolica de Chile