Computed Inspiratory Muscle Pressure to Monitor Inspiratory Effort During Pressure Support Ventilation

November 6, 2026 updated by: Jian-Xin Zhou

Validation of Computed Inspiratory Muscle Pressure to Monitor Inspiratory Effort During Pressure Support Ventilation: A Prospective Physiological Study

The goal of this study is to validate computed inspiratory muscle pressure (cPmus) for monitoring inspiratory effort in adults receiving pressure support ventilation. Researchers will compare cPmus with reference inspiratory muscle pressure calculated using an esophageal balloon catheter, a thin pressure-measuring tube placed in the esophagus. The study will look at how closely the two methods are related and whether they give similar results. Participants will undergo simultaneous monitoring with cPmus and an esophageal balloon catheter. Researchers will adjust pressure support across six levels, recording measurements from both methods at each level.

Study Overview

Detailed Description

This is a prospective validation study with repeated measurements. It aims to validate computed inspiratory muscle pressure (cPmus), a noninvasive estimate of inspiratory muscle pressure provided by the study ventilator (Prunus Padus 9, Shenzhen, China). The reference method is esophageal pressure-derived inspiratory muscle pressure (Pmus). The study will enroll adults receiving invasive pressure support ventilation (PSV).

After obtaining informed consent, participants will undergo simultaneous monitoring with the cPmus algorithm and an esophageal balloon catheter. Pressure support will be adjusted in six levels. Positive end-expiratory pressure (PEEP) will remain unchanged. Each pressure support level will be maintained for 10 minutes. Brief end-expiratory and end-inspiratory occlusion maneuvers will also be performed at each level to obtain additional indices of respiratory drive and inspiratory effort. Esophageal balloon will be removed after completing the last pressure support step.

At each pressure support level, paired values of cPmus and reference Pmus were measured. The corresponding inspiratory pressure-time products, cPTPmus and PTPmus, will also be calculated.

All procedures will follow the study protocol and standardized measurement procedures. Study data will be recorded in case report forms and an electronic database, with checks for completeness, accuracy, and waveform quality.

Study Type

Interventional

Enrollment (Estimated)

30

Phase

  • 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 Contact

Study Contact Backup

Study Locations

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

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. Age 18 years or older.
  2. Receiving pressure support ventilation.
  3. Written informed consent provided by the participant or a legally authorized representative.

Exclusion Criteria:

  1. Contraindication to esophageal catheter placement, including uncontrolled coagulopathy, skull base fracture, upper gastrointestinal bleeding, tumor or surgery, neck surgery, or esophagogastric varices.
  2. Chest trauma, a postoperative state following lung surgery, an active pulmonary air leak (pneumothorax, pneumomediastinum, or bronchopleural fistula), or an indwelling chest drain.
  3. Neuromuscular disease, diaphragmatic dysfunction, or diaphragmatic surgery.
  4. Impaired central respiratory drive due to intracranial hypertension or brainstem injury.
  5. Hemodynamic instability, defined as mean arterial pressure <60 mmHg, systolic blood pressure >180 mmHg, heart rate <40 or >150 beats/min, or norepinephrine dose >1 mcg/kg/min.
  6. Pregnancy or breastfeeding.
  7. A decision to withdraw life-sustaining treatment or provide palliative care.

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: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Pressure support 15

Pressure support of 15 cm H2O will be applied for 10 minutes.

Pressure support of 15 cm H2O will be applied for 10 minutes.

Experimental: Pressure support 13

Pressure support of 13 cm H2O will be applied for 10 minutes.

Pressure support of 13 cm H2O will be applied for 10 minutes.

Experimental: Pressure support 11

Pressure support of 11 cm H2O will be applied for 10 minutes.

Pressure support of 11 cm H2O will be applied for 10 minutes.

Experimental: Pressure support 9

Pressure support of 9 cm H2O will be applied for 10 minutes.

Pressure support of 9 cm H2O will be applied for 10 minutes.

Experimental: Pressure support 7

Pressure support of 7 cm H2O will be applied for 10 minutes.

Pressure support of 7 cm H2O will be applied for 10 minutes.

Experimental: Pressure support 5

Pressure support of 5 cm H2O will be applied for 10 minutes.

Pressure support of 5 cm H2O will be applied for 10 minutes.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Computed inspiratory muscle pressure (cPmus)
Time Frame: 2 hours

Computed inspiratory muscle pressure (cPmus) will be measured.

2 hours
Inspiratory muscle pressure (Pmus)
Time Frame: 2 hours

Inspiratory muscle pressure (Pmus) will be measured.

2 hours
Computed inspiratory muscle pressure-time product (cPTPmus)
Time Frame: 2 hours

Computed inspiratory muscle pressure-time product (cPTPmus) will be measured.

2 hours
Inspiratory muscle pressure-time product (PTPmus)
Time Frame: 2 hours

Inspiratory muscle pressure-time product (PTPmus) will be measured.

2 hours

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Occluded airway pressure at 100ms (P0.1)
Time Frame: 2 hours

Occluded airway pressure at 100ms (P0.1) will be measured.

2 hours
Maximal decrease of airway pressure during end-expiratory occlusion (∆Pocc)
Time Frame: 2 hours

Maximal decrease of airway pressure during end-expiratory occlusion (∆Pocc) will be measured.

2 hours
Pressure muscle index (PMI)
Time Frame: 2 hours

Pressure muscle index (PMI) will be measured.

2 hours

Collaborators and Investigators

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

Sponsor

Investigators

  • Principal Investigator: Jian-Xin Zhou, Capital Medical 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)

October 22, 2026

Primary Completion (Estimated)

April 30, 2027

Study Completion (Estimated)

April 30, 2027

Study Registration Dates

First Submitted

October 15, 2026

First Submitted That Met QC Criteria

October 15, 2026

First Posted (Actual)

October 21, 2026

Study Record Updates

Last Update Posted (Actual)

November 9, 2026

Last Update Submitted That Met QC Criteria

November 6, 2026

Last Verified

November 1, 2026

More Information

Terms related to this study

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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