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Use of Transient Elastogaphy to Assess Diaphragm Function in Mechanically Ventilated Patients (Elasto-ICU)

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ClinicalTrials.gov Identifier: NCT03832231
Recruitment Status : Not yet recruiting
First Posted : February 6, 2019
Last Update Posted : February 6, 2019
Sponsor:
Information provided by (Responsible Party):
Assistance Publique - Hôpitaux de Paris

Brief Summary:

Mechanical ventilation is a life-saving treatment that can be associated with diaphragm dysfunction, a potentially deleterious acquired disability. It may be the consequence of disuse - under mechanical ventilation, respiratory muscles are unloaded - or the consequence of muscle overuse because of insufficient unloading. Evaluating diaphragm function is therefore crucial to optimally tailor the ventilator assistance. Measurement of transdiaphragmatic pressure (Pdi) is the reference method to assess diaphragm function but it invasiveness hinders the generalization of its use. Previous studies have reported that ultrasound can quantify diaphragm thickening and that diaphragm thickening fraction (TFdi) is a good marker of diaphragm function. Since diaphragm becomes stiffer when it contracts, the investigators aim at exploring whether the measurement of diaphragm stiffness by transient shear wave elastography would improve the evaluation of diaphragm function with ultrasound.

Therefore, the objectives of the study are to evaluate the performance of transient shear wave elastography applied to the diaphragm to estimate Pdi in mechanically ventilated patients as compared to TFdi and to correlate the changes in elastography derived indices, in TFdi and in Pdi into different ventilatory conditions and during a spontaneous breathing trial. Pdi will be obtained using catheters positioned in patients' stomachs and esophagus and diaphragm stiffness will be assessed by measuring the shear modulus of the diaphragm with a dedicated ultrasound machine (Aixplorer, Ultrasonic). TFdi will be also measured as previously reported. Pdi, TFdi and shear modulus will be measured at the end of each four following 10 minutes-conditions: 1) baseline with initial ventilator settings (set by the physician in charge of patient); 2) 25%-increase in pressure support and initial PEEP; 3) 25%-decrease in pressure support and initial PEEP and 4) initial level of pressure support and ZEEP. Finally, the same measurements will be done at the beginning of a 30 minutes spontaneous breathing trial.


Condition or disease Intervention/treatment Phase
Ventilator Weaning Intensive Care Unit Device: Shear Wave Elastography Not Applicable

Detailed Description:

Objective :

The main objective is to correlate ultrasound indices (thickness, thickening, rigidity) to the measurement of transdiaphragmatic pressure in the evaluation of the diaphragmatic function of patients under mechanical ventilation.

Secondary objectives are: 1. Correlate thickening of the diaphragm with Pdi, 2. Correlate diaphragmatic thickening with diaphragmatic stiffness 3. Describe these correlations under different levels of pressure ventilatory support, 4. Describe the evolution of diaphragmatic stiffness, thickening and Pdi pressure during a ventilator liberating trial.

The primary endpoint is the measurement of Pdi. The secondary endpoints are the diaphragm thickening fraction and diaphragm stiffness.

Methods :

The Pdi will be obtained by measuring the esophageal and gastric pressures through nasogastric tube equipped with balloons. The position of each of the balloons will be checked by displaying the esophageal and gastric pressure lines. The intragastric position will be confirmed by mild abdominal compression. The oesophageal position is based on visualization of cardiac artifacts on the pressure pattern and signal deflations related to inspiratory movements. The signals of the esophageal and gastric pressures will be displayed continuously and their resultant - transdiapragmatic pressure - will be automatically calculated in real time by the software. It will also record pressure in the airways at the endotracheal tube.

Patients will be placed in half-sitting position to allow better recognition of the diaphragm. Using the ultrasound system Aixplorer® (Aix en Provence, France V9), equipped with a high resolution probe (6 MHz). The probe will be positioned at the intercostal space above the tenth rib on the right axillary line and directed perpendicular to the diaphragm (apposition zone). The measurements will be performed "offline" and the calculation of the thickening fraction will be performed in blind clinical conditions.

The diaphragmatic elastography will be determined using the same ultrasound system (Aixplorer®, Aix en Provence, France V9, provided with a high resolution probe (SL10-2, central frequency, 6 MHz)). The anatomical approach is the same as the intercostal approach described previously. After finding the diaphragm in B mode, a transition to SWE (elastography) mode will be performed. Three successive measurements will be made on the same region of interest, the average of the three measurements will be retained. The variation of the shear modulus during the inspiratory time will also be calculated post hoc. As for standard ultrasound, records analysis will be performed in blind conditions.

Pdi, ultrasound derived indices and shear wave modulus will be measured under several conditions.

  1. At baseline: initial ventilator settings set by the physician in charge of patient
  2. 25%-increase in pressure support and initial PEEP during 10 minutes
  3. 25%-decrease in pressure support and initial PEEP during 10 minutes
  4. initial level of pressure support without PEEP (PEEP = 0) during 10 minutes
  5. Measurement of the maximal inspiratory pressure during an inspiratory occlusion maneuver lasting 20 seconds.
  6. A 30 minutes Ventilator liberating trial without PEEP nor Pressure Support (CPAP=0)

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 30 participants
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Diagnostic
Official Title: Evaluation of Diaphragmatic Function in Mechanically Ventilated Patients With Transient Shear Wave Elastography
Estimated Study Start Date : February 2019
Estimated Primary Completion Date : September 2019
Estimated Study Completion Date : September 2019

Arm Intervention/treatment
Experimental: Ventilator liberating trial
The diaphragmatic function of patients undergoing a ventilator liberating trial will be determined with transient shear wave elastography.
Device: Shear Wave Elastography
Ultrasound technology to assess tissue stiffness




Primary Outcome Measures :
  1. Change in transdiaphragmatic pressure [ Time Frame: Through patient participation, an average of 1 day ]
    Reference method to assess diaphragm function computed as the difference between esophageal pressure and gastric pressure


Secondary Outcome Measures :
  1. Change in diaphragm thickness and thickening as expressed by the thickening fraction (ratio of the difference between inspiratory and expiratory thickness over expiratory thickness). [ Time Frame: Through patient participation, an average of 1 day ]
    Using the ultrasound system Aixplorer® (Aix en Provence, France V9), equipped with a high resolution probe (6 MHz), anatomical structures will be identify using B-mode. A switch to TM-mode will allow us to measure the thickening fraction. A second switch to shear wave elastography allows to identify an elastography map of the diaphragm and calculate an average of the shear wave modulus.

  2. Change in diaphragm stiffness [ Time Frame: Through patient participation, an average of 1 day ]
    Using the ultrasound system Aixplorer® (Aix en Provence, France V9), equipped with a high resolution probe (6 MHz), anatomical structures will be identify using B-mode. A switch to TM-mode will allow us to measure the thickening fraction. A second switch to shear wave elastography allows to identify an elastography map of the diaphragm and calculate an average of the shear wave modulus.

  3. Success or failure at the spontaneous breathing trial [ Time Frame: Through patient participation, an average of 1 day ]
    Presence of clinical intolerance criteria according to Boles et al. ERJ 20107



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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

All patients receiving mechanical ventilation and having spontaneous efforts will be eligible if they meet the following criteria:

Inclusion criteria

  • Age ≥ 18 years old
  • Intubation and mechanical ventilation since 24 hours
  • Failure to a first ventilator liberating trial
  • nasogastric feeding tube in place
  • readiness criteria to undertake a ventilator liberating trial (Boles et al. ERJ 2007)
  • patient written consent or next of kin written consent in case of physical inability of the patient to sign the consent form
  • french social Health Service registration

Exclusion criteria

  • pregnancy
  • protective administrative control
  • patient's refusal
  • contra indications to the insertion of esophageal and gastric balloons
  • allergy to topical anesthetic
  • impossible weaning (full dependance to mechanical ventilation)

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03832231


Contacts
Contact: Martin DRES, MD, PhD 33(0)1 42 16 77 61 martin.dres@aphp.fr
Contact: Alexandre DEMOULE 33(0)1 42 16 77 61 alexandre.demoule@aphp.fr

Locations
France
Groupe Hospitalier Pitié-Salpétrière Not yet recruiting
Paris, France, 75013
Contact: Martin DRES, MD, PhD         
Sponsors and Collaborators
Assistance Publique - Hôpitaux de Paris
Investigators
Principal Investigator: Martin DRES, MD, PhD Assistance Publique Hoptiaux de Paris

Responsible Party: Assistance Publique - Hôpitaux de Paris
ClinicalTrials.gov Identifier: NCT03832231     History of Changes
Other Study ID Numbers: APHP180264
2018-A02311-54 ( Other Identifier: ANSM )
First Posted: February 6, 2019    Key Record Dates
Last Update Posted: February 6, 2019
Last Verified: January 2019

Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No

Keywords provided by Assistance Publique - Hôpitaux de Paris:
Shear wave elastography
Ultrasonography
Transdiaphragmatic pressure
Diaphragmatic function
Mechanical ventilation