Recruiting

PMI in PSV

Sponsor:

Unity Health Toronto

Code:

NCT06494085

Conditions

Acute Hypoxemic Respiratory Failure

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Measuring Respiratory Mechanics

Randomized Pressure Support

Study Details

Brief summary:

Pressure support ventilation (PSV) is used to assist the breathing of the intubated patient with some pressure from the ventilator. This support aims at avoiding excessive inspiratory effort, while ensuring a certain degree of training of the patient's inspiratory muscle. Avoiding both minimal and excessive assistance is thus important for the optimal care of the intubated patient ensuring a lung and diaphragm protective ventilation with the goal to liberate the patient from the ventilator as soon as possible.

Recently pressure-muscle-index (PMI), an index of inspiratory effort easy to be measured on the ventilator screen, has been proposed to avoid excessive assistance in PSV. This will be the first prospective study testing the effects of setting pressure support based on PMI to avoid excessive assistance on patients recovering from acute lung injury (acute hypoxemic respiratory failure).

Conditions

Acute Hypoxemic Respiratory Failure

Study ID

NCT06494085

Start date

Oct 4, 2024

Status verified date

Aug, 2024

Completion date

Feb 28, 2026

Anticipated

Primary completion date

Feb 28, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • >18 y.o.
  • Invasively ventilated in Intensive Care Unit.
  • Diagnosed with acute hypoxemic respiratory failure (P/F<300 mmHg).
  • Breathing on pressure support ventilation.

Exclusion Criteria:

  • <18 y.o.
  • Contraindication for Electrical Impedence Tomography monitoring (e.g. pacemaker, burns, or - wounds limiting electrode placement).
  • Severe and previously diagnosed neurological and neuromuscular disease.
  • Psychomotor agitation (Sedation Agitation Scale > 4).

Study Design

Enrollment

20 participants

Anticipated

Interventions and Outcome Measures

Interventions

Measuring Respiratory Mechanics

First, for each patient enrolled we will perform inspiratory and expiratory occlusions - routinely performed diagnostic maneuvers to measure patient's breathing effort - at the clinically set level of breathing assistance by the mechanical ventilator. Importantly, we will measure pressure-muscle-index (PMI).

Second, we will set the level of assistance (i.e. pressure support, PS) in order to make PMI=0. The PS level at which PMI=0 (PS PMI=0) will be used as reference for the study protocol. After 5 minutes at PS PMI=0 we will perform inspiratory and expiratory occlusions.

Randomized Pressure Support

3 steps of PS above (+2, +4, +6 cmH2O) and 3 below (-2, -4, -6 cmH2O) PSPMI=0 done in a randomized order (sequence in envelopes opened blindly by the investigators). Each step will last ≤5 minutes if poorly tolerated (see tolerance rule in description). At the end of each step we will perform 1 inspiratory occlusion and 3 expiratory occlusions. Each of the expiratory occlusion will be separated by 30 seconds in order to restore the patient's breathing pattern. We will resume a 3-minutes clinical PS in between each step to minimize changes in PaCO2. If not yet comprised by the study steps each patient will undergo an adjunctive 5 minutes step at PS 0 (zero) cmH2O.

Primary outcome measure

  • Inspiratory Occlusion [ Time Frame: 60 minutes ]
  • Pressure Muscle Index (PMI) [ Time Frame: 60 minutes ]

Central Contacts and Locations

Central contacts

Laurent Brochard, MD, PhD

4168645686laurent.brochard@unityhealth.to

Locations

St. Michael's Hospital

Recruiting

Toronto, Ontario, Canada, M5B 1W8

Contacts

Laurent Brochard, MD

laurent.brochard@unityhealth.to

More Information

Sponsor

Unity Health Toronto

Last update posted

May 20, 2025

Last verified

Aug, 2024

Keywords

  • Mechanical Ventilation
  • Intensive Care Unit
  • Pendelluft
  • Pressure Support Ventilation

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Unity Health Toronto on 2025-05-20.