Diaphragmatic Speckle Tracking During Spontaneous Breathing Trial

Study Overview
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Brief Summary
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Currently, measurement of transdiaphragmatic pressure (Pdi) using oesophageal and gastric balloons is the gold standard for the assessment of diaphragmatic effort. This technique is relatively invasive and its interpretation may be complex. The diaphragmatic longitudinal strain (LSdi) and strain rate (LSRdi) might provide additional information in the assessment of diaphragmatic effort and movement during SBT, allowing early detection of diaphragmatic dysfunction. Patients will be monitored during a 30-120 minutes SBT consisting of no assistance on the ventilator using CPAP with a pressure level of 0 cmH2O. Parameters to evaluate diaphragm function will include diaphragmatic strain (LSdi and LSRdi), diaphragmatic thickening fraction (TFdi), and airway occlusion pressure (ΔP0.1 and ΔPocc). These parameters will be measured immediately before ('baseline') the SBT, as well as 2 minutes ('early' assessment), 15 ('intermediate' assessment) and 30 minutes ('late' assessment) after the beginning of the SBT.

Official Title
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DIAPHRAGMATIC SPECKLE TRACKING DURING SPONTANEOUS BREATHING TRIAL

Conditions
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Weaning, Spontaneous Breathing Trial, Mechanical Ventilation, Speckle Tracking, Strains, Diaphragm

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Consecutive adult patients (≥18 years old) undergoing mechanical ventilation for at least 24h (regardless of the reason of intubation) patients fulfilling criteria for an SBT patients will have to be able to trigger ventilator breaths with a reasonable level of assistance, patients with lack of severe impairment in gas exchange, patients that not require significant hemodynamic support. Patients will be recruited by the study coordinator following completion of informed consent from the patient or legally authorized substitute decision maker. Exclusion Criteria: Use of pressure support during the SBT. Severe hemodynamic instability (>30% increase in vasopressors in the last 6 hours or norepinephrine > 0.5 µg/kg/min). Severe or very severe chronic obstructive pulmonary disease (COPD) according to the GOLD criteria (stage III: FEV1 30-50% predicted; stage IV: FEV1 < 30% predicted). Known or suspected severe or progressive neuromuscular disorder likely to result in prolonged or chronic ventilator dependence Clinical judgement of the attending physician.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| adult patients undergoing mechanical ventilation<br> | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| changes of diaphragmatic longitudinal strain between baseline and during Spontaneous breathing trial | diaphragmatic longitudinal strain is LSdi Spontaneous breathing trial is SBT | 7 days | 
| changes of diaphragmatic longitudinal strain strain rate between baseline and during Spontaneous breathing trial | diaphragmatic longitudinal strain strain rate is LSRdi Spontaneous breathing trial is SBT | 7 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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weaning, spontaneous breathing trial, mechanical ventilation, speckle tracking, Strains, diaphragm