Prevalence and Clinical Impact of Airway Opening Pressure in Post-Cardiac Surgery Patients

September 16, 2025 updated by: François Lellouche, Laval University

Prevalence and Clinical Impact of Airway Opening Pressure in Post-Cardiac Surgery Patients: A Prospective Observational Study

Airway opening pressure is a key parameter in assessing respiratory mechanics. Current practice primarily relies on indirect assessments of lung mechanics, but growing evidence suggests that direct airway opening pressure measurement could enhance individualized ventilatory strategies. Significant airway opening pressure suggests incomplete alveolar recruitment at end-expiration, which may contribute to ventilation-perfusion mismatch, increased respiratory effort, and postoperative pulmonary complications such as atelectasis and impaired gas exchange. Determining the prevalence and clinical relevance of significant airway opening pressure in post-cardiac surgery patients could contribute to more personalized respiratory strategies and improve postoperative care.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
196

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
    • Quebec
      • Québec, Quebec, Canada
        • Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adult (≥18 years)
  • Undergoing elective coronary artery bypass grafting (CABG) or valve surgery, or combined procedures with expected postoperative mechanical ventilation

Exclusion Criteria:

- Patient receiving invasive mechanical ventilation prior to surgery

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Other: Post operative cardiac surgery
Diagnostic test: Airway opening pressure
Airway opening pressure will be measured within one hour of intensive care unit admission (using a standardized low-flow insufflation maneuver flow 5-6 LPM). The inflection point on the pressure-time or pressure-volume waveform- depending on ventilator model-will define the airway opening pressure.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Prevalence of significant airway opening pressure
Time Frame: up to 1 hour after intensive care admission
airway opening pressure ≥ 5 cmH₂O
up to 1 hour after intensive care admission

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Airway opening pressure prevalence based on body mass index
Time Frame: up to 1 hour
Airway opening pressure prevalence base on Obesity status (body mass index ≥30 vs. <30 kg/m²)
up to 1 hour
Airway opening pressure prevalence based on cardiopulmonary bypass duration
Time Frame: up to 1 hour
Airway opening pressure prevalence based on cardiopulmonary bypass duration (minutes)
up to 1 hour
Airway opening pressure prevalence based on left ventricular dysfunction
Time Frame: up to 1 hour
Airway opening pressure prevalence based on left ventricular dysfunction (Ieft ventricular ejection fraction < 50 percent vs > 50 percent)
up to 1 hour
Airway opening pressure prevalence based on inotropic support
Time Frame: up to 1 hour
Airway opening pressure prevalence based on use of amines (< 0.1 mcg/kg/min or norepinephrine equivalent vs > 0.1 mcg/kg/min or norepinephrine equivalent)
up to 1 hour
Airway opening pressure prevalence based on age
Time Frame: up to 1 hour
Airway opening pressure prevalence base on age
up to 1 hour
Airway opening pressure prevalence based on intraoperative fluid balance
Time Frame: up to 1 hour
Airway opening pressure prevalence base on intraoperative fluid balance
up to 1 hour
Feasibility of airway opening pressure measurement
Time Frame: up to 1 hour
proportion of patients in whom the maneuver is successfully completed
up to 1 hour
Positive end expiratory pressure level
Time Frame: up to 1 hour
Number of times Positive end expiratory pressure is set greater than measured airway opening pressure
up to 1 hour
Extubation
Time Frame: Day7
Correlation between airway opening pressure and time to extubation
Day7
Patient position
Time Frame: up to 1 hour
Comparison of airway opening pressure values in flat versus semi-recumbent (30-degree) positions
up to 1 hour
Hemodynamic tolerance base on blood pressure drop
Time Frame: up to 15 minutes
Evaluation of hemodynamic tolerance based on arterial pressure during positive end-expiratory pressure adjustment (if inotropic agents are required, an increase of more than 0.05 mcg/kg/min in norepinephrine equivalent is considered significant)
up to 15 minutes
Hemodynamic tolerance base on pulse oxygen saturation drop
Time Frame: up to 15 minutes
Evaluation of hemodynamic tolerance based on pulse oxygen saturation. A decrease in pulse oxygen saturation of 5 percent from baseline or more is considered significant.
up to 15 minutes
Non-interruptive airway opening pressure measurement method
Time Frame: up to 1 hour
The novel non-interruptive airway opening pressure measurement method will be validated
up to 1 hour

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Laval University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 27, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 27, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 16, 2025

First Posted (Estimated)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 23, 2025

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 23, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 16, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2025

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2026-4399

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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