Acute Respiratory DiseasePoccUSNCT07564258
Estimation of P0.1 Using Ultrasound Indexes of Diaphragm Function
An observational study of Acute Respiratory Disease, run by Assistance Publique - Hôpitaux de Paris.
Trial summary
Occlusion pressure at 100 ms (P0.1) is a reliable and non-invasive index of inspiratory drive that can be measured easily on most ventilator. Unfortunately, P0.1 cannot be measured reliably in non-intubated patients. In those receiving non-invasive ventilation, the measurement of P0.1 might be inaccurate due to leaks. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Acute Respiratory Disease
- What is being tested?
- Spontaneous breathing trial
- Type of treatment
- Medical device
- How many people
- 40 participants
- Where
- No sites listed yet
- Study dates
- Sep 2026to Jan 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Patients admitted to the intensive care unit who are intubated or have undergone a tracheostomy.
Who may be able to join
- - Age ≥ 18 years old
- Patient intubated or tracheostomized
- Decision by the clinician in charge to initiate a SBT
- After information, the patient or next of kind did not refuse to participate (according to the French law, written informed consent is waived)
Who cannot join
- - Suspicion of diaphragmatic nerves injury
- Preexisting neuromuscular disease
- Spinal cord injury above C5
- Neuromuscular blockade within last 24 hours
- Body mass index > 40 kg/m2
- Pregnancy or breast feeding
- Patient under legal protection
About this study
Official title: Estimation of Airway Occlusion Pressure at 100 ms Using Ultrasound Indexes of Diaphragm Function
Occlusion pressure at 100 ms (P0.1) is a reliable and non-invasive index of inspiratory drive that can be measured easily on most ventilator. Unfortunately, P0.1 cannot be measured reliably in non-intubated patients. In those receiving non-invasive ventilation, the measurement of P0.1 might be inaccurate due to leaks. P0.1 cannot be measured at all in patients receiving high-flow nasal canulae (HFNC).
Ultrasound indices of diaphragm contractile function, namely diaphragm excursion, velocity and thickening fraction, could be reliable and non-invasive proxies of respiratory drive in non-intubated patient.
Our hypothesis is that ultrasound indices of diaphragm function may reliably estimate P0.1. To validate this hypothesis, theses indices will be measured simultaneously with P0.1 in intubated patients, during diaphragm loading conditions similar to spontaneous breathing: the spontaneous breathing trial (SBT). The SBT is used to evaluate if patients can breathe without the assistance provided by the ventilator, and thus, be weaned from mechanical ventilation.
- Conditions
- Acute Respiratory Disease
- Being tested
- Spontaneous breathing trial
- Keywords
- acute respiratory failure, respiratory drive, P0.1, Airway occlusion pressure, Diaphragm, ultrasonography doppler
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Spontaneous breathing trialDevice
A plateau pressure measurement will be performed before starting the spontaneous breathing trial (SBT). Then, immediately and 5, 10, 15, 20, 25, and 30 minutes after the start of the SBT, the following will be performed as part of the study:
- Subcostal diaphragmatic ultrasound: M-mode and tissue Doppler
- Lateral diaphragmatic ultrasound: 2D mode and M-mode
- Measurement of P0.1
- Measurement of Pocc during a tele-expiratory pause, only 5 minutes after the start of the SBT.
What is being measured
The primary outcome is the main question the study is designed to answer.
P0.1 and Peak contraction velocity 5 minutes after the initiation of the SBT
Airway occlusion pressure measured 100 ms after the initiation of the inspiration, compared to peak contraction velocity of the diaphragm, measured by subcostal ultrasound in TDI-mode
Measured: 5 minutes after the initiation of the SBT
Secondary outcomes (8)
P0.1 and EXdi
Airway occlusion pressure measured 100 ms after the initiation of the inspiration, compared to maximal excursion of the diaphragm, measured by subcostal ultrasound in M-mode
Measured: Immediately after the initiation of the SBT then 5, 10, 15, 20, 25 and 30 minutes after the initiation of the SBT
P0.1 and Peak contraction velocity
Airway occlusion pressure measured 100 ms after the initiation of the inspiration, compared to peak contraction velocity of the diaphragm, measured by subcostal ultrasound in TDI-mode
Measured: Immediately after the initiation of the SBT then 10, 15, 20, 25 and 30 minutes after the initiation of the SBT
P0.1 and EXdi,0.1
Airway occlusion pressure measured 100 ms after the initiation of the inspiration, compared to excursion of the diaphragm measured 100 ms after the beginning of the inspiration, measured by subcostal ultrasound in M-mode
Measured: Immediately after the initiation of the SBT then 10, 15, 20, 25 and 30 minutes after the initiation of the SBT
P0.1 and Velocity Time Integral
Airway occlusion pressure measured 100 ms after the initiation of the inspiration, compared to velocity time integral of the diaphragm, measured by subcostal ultrasound in TDI-mode
Measured: Immediately after the initiation of the SBT then 10, 15, 20, 25 and 30 minutes after the initiation of the SBT
P0.1 and Peak relaxation velocity
Airway occlusion pressure measured 100 ms after the initiation of the inspiration, compared to peak relaxation velocity of the diaphragm, measured by subcostal ultrasound in TDI-mode
Measured: Immediately after the initiation of the SBT then 10, 15, 20, 25 and 30 minutes after the initiation of the SBT
P0.1 and Peak relaxation rate
Airway occlusion pressure measured 100 ms after the initiation of the inspiration, compared to peak relaxation rate of the diaphragm, measured by subcostal ultrasound in TDI-mode
Measured: Immediately after the initiation of the SBT then 10, 15, 20, 25 and 30 minutes after the initiation of the SBT
P0.1 and TFdi
Airway occlusion pressure measured 100 ms after the initiation of the inspiration, compared to thickening fraction of the diaphragm, measured by intercostal ultrasound in M-mode.
Measured: Immediately after the initiation of the SBT then 10, 15, 20, 25 and 30 minutes after the initiation of the SBT
P0.1 and mean thickening velocity
Airway occlusion pressure measured 100 ms after the initiation of the inspiration, compared to mean thickening velocity of the diaphragm, measured by intercostal ultrasound in M-mode.
Measured: Immediately after the initiation of the SBT then 10, 15, 20, 25 and 30 minutes after the initiation of the SBT
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 May 2026
- Study startSep 2026 (estimated)
- Primary completionJan 2027 (estimated)
- Study completionJan 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Acute Respiratory DiseaseStudies of the same condition, open and under way.
- More trials run by Assistance Publique - Hôpitaux de ParisThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Assistance Publique - Hôpitaux de Paris
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07564258
- Sponsor's protocol ID
- APHP260589
- Acronym
- PoccUS
- Status last verified
- Apr 2026
- First submitted
- 27 Apr 2026
- Last updated
- 25 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: The procedures carried out with the French data privacy authority (CNIL, Commission nationale de l'informatique et des libertés) do not provide for the transmission of the database, nor do the information and consent documents signed by the patients. Consultation by the editorial board or interested researchers of individual participant data that underlie the results reported in the article after deidentification may nevertheless be considered, subject to prior determination of the terms and conditions of such consultation and in respect for compliance with the applicable regulations.
Study at a glance
From the registry record, last updated by the sponsor on 25 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Estimation of Airway Occlusion Pressure at 100 ms Using Ultrasound Indexes of Diaphragm Function
- ClinicalTrials.gov ID
- NCT07564258
- Acronym / sponsor ID
- PoccUS / APHP260589
- Conditions
- Acute Respiratory Disease
- Keywords
- acute respiratory failure, respiratory drive, P0.1, Airway occlusion pressure, Diaphragm, ultrasonography doppler
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- Assistance Publique - Hôpitaux de ParisUniversity, hospital or other
- Study start
- Sep 2026 (estimated)
- Primary completion
- Jan 2027 (estimated)
- Study completion
- Jan 2027 (estimated)
- First posted
- 4 May 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Occlusion pressure at 100 ms (P0.1) is a reliable and non-invasive index of inspiratory drive that can be measured easily on most ventilator. Unfortunately, P0.1 cannot be measured reliably in non-intubated patients. In those receiving non-invasive ventilation, the measurement of P0.1 might be inaccurate due to leaks. P0.1 cannot be measured at all in patients receiving high-flow nasal canulae (HFNC).
Ultrasound indices of diaphragm contractile function, namely diaphragm excursion, velocity and thickening fraction, could be reliable and non-invasive proxies of respiratory drive in non-intubated patient.
Our hypothesis is that ultrasound indices of diaphragm function may reliably estimate P0.1. To validate this hypothesis, theses indices will be measured simultaneously with P0.1 in intubated patients, during diaphragm loading conditions similar to spontaneous breathing: the spontaneous breathing trial (SBT). The SBT is used to evaluate if patients can breathe without the assistance provided by the ventilator, and thus, be weaned from mechanical ventilation.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patients admitted to the intensive care unit who are intubated or have undergone a tracheostomy.
Key inclusion criteria (4 listed)
- - Age ≥ 18 years old
- Patient intubated or tracheostomized
- Decision by the clinician in charge to initiate a SBT
- After information, the patient or next of kind did not refuse to participate (according to the French law, written informed consent is waived)
Key exclusion criteria (7 listed)
- - Suspicion of diaphragmatic nerves injury
- Preexisting neuromuscular disease
- Spinal cord injury above C5
- Neuromuscular blockade within last 24 hours
- Body mass index > 40 kg/m2
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Spontaneous breathing trialA plateau pressure measurement will be performed before starting the spontaneous breathing trial (SBT). Then, immediately and 5, 10, 15, 20, 25, and 30 minutes after the start of the SBT, the following will be performed as part of the study: * Subcostal diaphragmatic ultrasound: M-mode and tissue Doppler * Lateral diaphragmatic ultrasound: 2D mode and M-mode * Measurement of P0.1 * Measurement of Pocc during a tele-expiratory pause, only 5 minutes after the start of the SBT. | Device | – |
Primary outcome
P0.1 and Peak contraction velocity 5 minutes after the initiation of the SBT
Time frame: 5 minutes after the initiation of the SBT
Airway occlusion pressure measured 100 ms after the initiation of the inspiration, compared to peak contraction velocity of the diaphragm, measured by subcostal ultrasound in TDI-mode
8 secondary outcomes
P0.1 and EXdi
Time frame: Immediately after the initiation of the SBT then 5, 10, 15, 20, 25 and 30 minutes after the initiation of the SBT
P0.1 and Peak contraction velocity
Time frame: Immediately after the initiation of the SBT then 10, 15, 20, 25 and 30 minutes after the initiation of the SBT
P0.1 and EXdi,0.1
Time frame: Immediately after the initiation of the SBT then 10, 15, 20, 25 and 30 minutes after the initiation of the SBT
P0.1 and Velocity Time Integral
Time frame: Immediately after the initiation of the SBT then 10, 15, 20, 25 and 30 minutes after the initiation of the SBT
P0.1 and Peak relaxation velocity
Time frame: Immediately after the initiation of the SBT then 10, 15, 20, 25 and 30 minutes after the initiation of the SBT
P0.1 and Peak relaxation rate
Time frame: Immediately after the initiation of the SBT then 10, 15, 20, 25 and 30 minutes after the initiation of the SBT
P0.1 and TFdi
Time frame: Immediately after the initiation of the SBT then 10, 15, 20, 25 and 30 minutes after the initiation of the SBT
P0.1 and mean thickening velocity
Time frame: Immediately after the initiation of the SBT then 10, 15, 20, 25 and 30 minutes after the initiation of the SBT
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Aug 2026.
- Individual participant dataSharing planned: Yes. The procedures carried out with the French data privacy authority (CNIL, Commission nationale de l'informatique et des libertés) do not provide for the transmission of the database, nor do the information and consent documents signed by the patients. Consultation by the editorial board or interested researchers of individual participant data that underlie the results reported in the article after deidentification may nevertheless be considered, subject to prior determination of the terms and conditions of such consultation and in respect for compliance with the applicable regulations.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
The record lists no contact. Use the official record to reach the sponsor.
Questions about this trial
What is this clinical trial studying?
An observational study of Acute Respiratory Disease, run by Assistance Publique - Hôpitaux de Paris.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 25 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
P0.1 and Peak contraction velocity 5 minutes after the initiation of the SBT (time frame: 5 minutes after the initiation of the SBT). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 25 Aug 2026.