An observational study in Acute Respiratory Disease, sponsored by Assistance Publique - Hôpitaux de Paris. Not yet recruiting. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-25.
Sponsored by Assistance Publique - Hôpitaux de Paris · Observational
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.
Assistance Publique - Hôpitaux de Paris is the lead sponsor of 3,505 studies on the registry; 1,006 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Patients admitted to the intensive care unit who are intubated or have undergone a tracheostomy.
Exclusion Criteria:
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.
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
Time frame: 5 minutes after the initiation of the SBT
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
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
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
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
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
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
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
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
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
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
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
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
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.
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
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.
Time frame: Immediately after the initiation of the SBT then 10, 15, 20, 25 and 30 minutes after the initiation of the SBT
No study locations are listed for this record.
Plan to share: 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.
Supporting information: Study protocol, Icf
No publications or documents are linked to this record.
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Assistance Publique - Hôpitaux de Paris