Impact of PEEP on Respiratory Effort During Assisted Ventilation

ConditionsMechanical Ventilation Respiratory Failure Effort

Trial statusRecruiting

Trial phaseNot applicable

Trial typeInterventional

Biological sexAll

Age18+

SponsorPontificia Universidad Catolica de Chile

About this trial

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.

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

Age ≥18 years.

ICU patients receiving invasive mechanical ventilation (endotracheal tube or tracheostomy).

Ventilated in an assisted mode with spontaneous breathing

Clinically stable to undergo protocolized PEEP changes.

Disqualifiers

Contraindication to esophageal balloon placement (if applicable).

Significant hemodynamic instability or unstable vasopressor requirements.

Unstable arrhythmia or active myocardial ischemia.

Undrained pneumothorax or major air leak.

Trial design

Design model

Crossover

Treatments tested in this trial

PEEP Level Adjustment
Other intervention
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.

Treatment groups

12 Participants

are divided into 4 treatment groups

Group A: PEEP 0 cmH₂OExperimental treatment 1 intervention

Group B: PEEP 5 cmH₂OExperimental treatment 1 intervention

Group C: PEEP 10 cmH₂OExperimental treatment 1 intervention

Group D: PEEP 15 cmH₂OExperimental treatment 1 intervention

Trial outcomes

Primary outcomes

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