Multicenter, Multinational, Follow-Up Clinical Trial of the Performance of RESPINOR DXT to Identify Patients at Increased Risk of Weaning Failure
Condition: Respiratory Failure
MeSH terms: Respiratory Insufficiency
Study type: Observational

Summary: 
      The study will be a multicenter, multinational, prospective single arm blinded
      non-interventional follow-up study (from DXT-CS-005) to validate RESPINOR DXT's performance
      to identify patients at increased risk of weaning failure during the spontaneous breathing
      trial (SBT). Continuous diaphragmatic excursion measurements by RESPINOR DXT will be
      conducted during the patients' first SBT. The recording shall be initiated 15 minutes prior
      to the first SBT and will end 15 minutes post SBT.

      All patients on mechanical ventilation in the ICU meeting the eligibility criteria shall
      undergo a daily screen for weaning readiness. If any of the components of the daily screen is
      not met, the patient will not undergo a SBT that day and continued to be screened daily.
      Patients passing daily screening criteria shall automatically receive an SBT.

      The SBT shall last for 30-120 minutes and be performed on continuous positive airway pressure
      up to 5 cm H2O and pressure support up to 7 cm H2O. The SBT shall be terminated, and
      mechanical ventilation reinstituted at the original settings if the patient meets any of the
      SBT failure criteria.

      A trial is considered successful, and physicians will be asked to approve extubation when the
      patient can breathe spontaneously for the whole trial.

      As part of the clinical investigation, patients shall be continued to be screened daily until
      extubation, 21 days after enrollment, the performance of tracheostomy, death, or withdrawal
      of care. All patients shall be followed until hospital discharge or death.
    

Detailed description: 
      Weaning will be conducted by the clinician in charge of the patient, in accordance with the
      rules of good practice from the international consensus conference on withdrawal from MV
      (Boles, et al., 2007). Patients eligible for the study will perform a first spontaneous
      breathing trial (SBT) during which they will remain connected to the ventilator for 30-120
      minutes on continuous positive airway pressure up to 5 cm H2O and pressure support up to 7 cm
      H2O, according to the recommendations of the international consensus conference on intensive
      care medicine (Boles, et al., 2007) and usual practices of the service.

      During the SBT, the diaphragm excursion (DE) and respiratory rate shall be measured
      continuously using the investigative device, RESPINOR DXT, designed by the sponsor, RESPINOR
      (Oslo, Norway) for all patients.The continuous measurements shall be initiated 15 minutes
      prior to the SBT and last until 15 minutes post SBT. The investigator will be blinded to the
      DXT output. The DXT control unit will only display the signal needed to confirm good quality.
      During blinding mode, all quantifiable data are hidden from the screen; In the case DXT does
      not initiate blinding mode, the investigators shall enter this in the eCRF and report to the
      sponsor. In case of blinding failure, the patient will be excluded from the primary and
      secondary endpoint analysis (data marked as missing). Sensitivity analyses may, however, be
      conducted by including data pertaining to such unblinded patients. The patient can still be
      included in the descriptive secondary endpoints (including safety).

      Additionally, information on VT and RR from the ventilator should be noted for the 2nd minute
      of the SBT.

      The SBT will be interrupted and considered a failure in case of any of the SBT failure
      criteria:

        -  Respiratory rate > 35 breaths/min

        -  Increased accessory muscle activity

        -  SpO2 persistently below 90% on FiO2 < 0.4

        -  Heart rate persistently above 140 beats/min

        -  Systolic arterial blood pressure < 90 mmHg or > 180 mmHg

        -  Appearance of cyanosis or mottling

        -  Depressed mental status or agitation

      A trial is considered successful, and physicians will be asked to approve extubation when the
      patient can breathe spontaneously for the whole trial. The patient may receive oxygen
      supplementation by nasal cannula or mask as needed.

      The pathophysiology of weaning failure is often complex and multifactorial-respiratory,
      cardiac, and neurological problems can all cause weaning failure, especially in patients who
      have had prolonged stays in intensive care. It is therefore important to take a structured
      approach, identifying each factor and addressing it in turn. The physician will therefore log
      the failure criteria as well as the underlying reason for weaning failure.

      Depressed mental status is one of the failure criteria of spontaneous breathing trials. A
      patient can have resolution of the acute phase of the disease for which the patient was
      intubated as well as adequate respiratory and cardiac function, but still have a depressed
      mental status leading to weaning failure. Depressed mental status will, in most cases, not
      affect the DE, and as such, DXT cannot predict patients who have weaning failure solely due
      to depressed mental status. Another cause for weaning failure unrelated to the DE is
      congestive heart failure. Consequently, if a patient has weaning failure solely due to
      depressed mental status or congestive heart failure, the patient will be excluded from the
      primary endpoint analysis.
    

Intervention name(s): RESPINOR DXT
Intervention type(s): Device
Intervention description(s): Blinded, continuous diaphragmatic excursion measurements by DXT will be conducted during the patients' first SBT. The recording shall be initiated 15 minutes prior to the first SBT and will end 15 minutes post SBT.
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Patients under invasive mechanical ventilation in the intensive care unit.
      
Keywords: Diaphragm ultrasound; Diaphragm function; Mechanical ventilation