RecruitingNot ApplicableNCT07203781

PEEP-induced Effects on Respiratory dRivE and EFfort

Unraveling PEEP-induced Effects on Respiratory dRivE and EFfort in Acute Hypoxemic Respiratory Failure: the REEF Study

Sponsor

Radboud University Medical Center

Enrollment

20 participants

Start Date

Sep 2, 2025

Study Type

INTERVENTIONAL

Conditions

Acute Hypoxemic Respiratory Failure ARDS (Moderate or Severe)

Summary

Rationale: In patients with acute hypoxemic respiratory failure (AHRF), preserving spontaneous breathing during mechanical ventilation offers physiological benefits, but also carries risks. While spontaneous breathing improves gas exchange and limits diaphragm atrophy, strong inspiratory efforts may worsen lung and diaphragm injury. Balancing these factors requires refined and tailored strategies, such as the modulation of PEEP. However, the impact of PEEP on neural respiratory drive and inspiratory effort is very heterogenous, and these two entities have only been studied separately in limited subsets of patients and healthy subjects. Additionally, it remains unclear whether the major determinant of PEEP-induced changes in respiratory drive and effort is represented by variations in diaphragm geometry, lung compliance, or by the presence of expiratory muscles recruitment, which may counteract its effect. Objective: The primary objective is to determine the effect of PEEP on diaphragm neuromechanical efficiency (i.e. an index of neural respiratory drive and inspiratory effort) in patients with acute hypoxemic respiratory failure during invasive assisted mechanical ventilation. The secondary objective is to determine the major physiological contributors to PEEP-mediated changes in diaphragm neuromechanical efficiency. Study design: Prospective, physiological study. Study population: Invasively mechanically ventilated adult patients admitted to the ICU. Intervention: For each patient, six different PEEP levels (15-12-10-8-5-2 cmH2O) will be tested during a decremental PEEP trial. During each step, neural respiratory drive, inspiratory effort, expiratory muscle activity, lung inflation pattern through electrical impedance tomography, respiratory muscle geometry and function through ultrasound and surface EMG, gas exchange and hemodynamics data will be collected. Main study parameters/endpoints: The primary outcome of the study will be the evaluation of PEEP-mediated changes in diaphragm neuromechanical efficiency (NME).

Eligibility

Min Age: 18 Years

Plain Language Summary

Simplified for easier understanding

This study is looking at how adjusting the pressure setting on a breathing machine (called PEEP — positive end-expiratory pressure) affects a critically ill patient's own breathing effort. The goal is to better understand how to set ventilators in a way that supports breathing without causing harm to the lungs or respiratory muscles. **You may be eligible if...** - You are over 18 years old - You are in the ICU with severe low oxygen levels (acute hypoxemic respiratory failure) - You are on an assisted breathing machine that supports but does not fully control your breaths - Your breathing efforts are measurable and active **You may NOT be eligible if...** - You have a pre-existing neuromuscular disease that affects breathing - You have chronic respiratory failure requiring long-term oxygen at home - Your muscles are fully paralyzed for medical reasons - You have a collapsed lung (pneumothorax) - You have conditions that prevent the monitoring devices used in this study from being placed (such as chest wounds, pacemaker, or certain surgeries) Talk to your doctor to see if this trial is right for you.

This summary was AI-generated to explain the trial in plain language. It is not medical advice. Always discuss eligibility with your doctor before enrolling in a clinical trial.

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Interventions

OTHERPEEP level changes

For each patient, six different PEEP levels (15-12-10-8-5-2 cmH2O) will be tested during a decremental PEEP trial. During each step, neural respiratory drive, inspiratory effort, expiratory muscle activity, lung inflation pattern through electrical impedance tomography, respiratory muscle geometry and function through ultrasound and surface EMG, gas exchange and hemodynamics data will be collected.