Impact of PEEP on Respiratory Effort During Assisted Ventilation

Summary

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.

Conditions

• Mechanical Ventilation
• Respiratory Failure
• Effort

Interventions

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.

Sponsors & Collaborators

• Clínica Universidad de los Andes

  collaborator OTHER

• Pontificia Universidad Catolica de Chile

  lead OTHER

Principal Investigators

• Roque Basoalto, PhD, Msc, Physioterapy · Pontifica Universidad Catolica de Chile

• Sebastian Morales, Physician · Pontifica Universidad Catolica de Chile

• Alejandro Bruh Bruhn · Pontifica Universidad Catolica de Chile

Study Design

Allocation

RANDOMIZED

Purpose

OTHER

Masking

NONE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2025-01-01

Primary Completion

2026-04-30

Completion

2026-07-31

Countries

• Chile

Study Locations