Pressure Muscle Index and Threshold of Over-assistance During Pressure Support Ventilation

NCT06494085 | Recruiting

• 1 other identifier: 24-105
• Study Type: observational
• Target: 20
• Locations: 1 country
• Sites: 1

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

Keywords

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

Outcome Measures

Primary Outcomes (2)

• Inspiratory Occlusion

  To investigate the role of the inspiratory occlusion as a diagnostic tool to understand the patient's desired tidal volume and minute ventilation in Pressure Support Ventilation (PSV),

  60 minutes

• Pressure Muscle Index (PMI)

  To investigate the role of a PMI\>0 strategy to avoid over-assistance in Pressure Support Ventilation

  60 minutes

Secondary Outcomes (2)

• Pendelluft

  60 minutes

• Lung and Diaphragm Protective Ventilation

  60 minutes

Interventions

Measuring Respiratory Mechanics OTHER

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 OTHER

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.

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

The Study population will include patients mechanically ventilated in the St. Michael's Intensive Care Unit. Patients who are younger than 18 years of age will be excluded from this study on the basis that the ICUs at St. Michael's Hospital are intended for adults; individuals aged less than 18 years are rarely, if ever, admitted.

You may qualify if:

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

You may not qualify if:

• \<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).

Sponsors & Collaborators

• Unity Health Toronto: lead

Study Sites (1)

St. Michael's Hospital

Toronto, Ontario, M5B 1W8, Canada

RECRUITING

MeSH Terms

Conditions

Respiratory Insufficiency

Condition Hierarchy (Ancestors)

Respiration Disorders; Respiratory Tract Diseases

Study Officials

• Laurent Brochard

  Unity Health Toronto - St. Michael's Hospital

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Laurent Brochard, MD, PhD

CONTACT

4168645686; laurent.brochard@unityhealth.to

Study Design

• Study Type: observational
• Observational Model: CASE CROSSOVER
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 2, 2024
• First Posted: July 10, 2024
• Study Start: October 4, 2024
• Primary Completion: February 28, 2026
• Study Completion: February 28, 2026
• Last Updated: May 20, 2025

Record last verified: 2024-08

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)