The ACCESSIT Study

Study Overview
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Brief Summary
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The study is designed to characterize and monitor the structure, degree of activation and function of the different respiratory muscles during mechanical ventilation after spine trauma and spinal cord injury.

Detailed Description
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In patients with spinal cord injury, separation from mechanical ventilation is an essential aspect of the prognosis. Denervation of specific muscles, as a consequence of the injury, can generate a dysfunction of the involved muscles and/or a disruption of their coordination during breathing. Respiratory muscle dysfunction is strongly associated with failure of weaning from mechanical ventilation. However, the pattern of activation and coordination of the different respiratory muscles, as well as their evolution over time, have been poorly investigated in spinal cord injury, particularly during the acute phase in intensive care unit. Assessing the structure, activity, and function of the respiratory muscles at different time points after the injury would help to better understand the natural course of respiration in these patients and the possible therapeutic approaches. In fact, depending on the activation/deactivation and residual function of the respiratory muscles, there might be potential for recovery and training, with the possibility of improving patients' clinical outcomes. In this preliminary physiological study, the investigators aim to assess the feasibility of monitoring non-invasively the respiratory muscles in mechanically ventilated adult patients with traumatic spine lesion, with and without spinal cord injury. The investigators also aim to assess, monitor, and compare over time the structure, degree of activation, function, and coordination of the different respiratory muscles. Because the diagnosis of spinal cord injury is not always made immediately in spine trauma patients, and because other factors related to chest or abdominal trauma could interfere with the respiratory pattern, the plan is to study and follow patients with spinal cord injury, using patients with traumatic spine lesion without spinal cord injury as controls.

Official Title
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Role of ACCESsory Muscles in Mechanically Ventilated Patients After Spinal Cord Injury and Trauma: a Physiological Study - The ACCESSIT Study

Conditions
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Respiratory Support

Intervention / Treatment
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* Other: Mechanical Ventilation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Presence of traumatic spine lesion (with and without spinal cord injury) Requiring invasive mechanical ventilation, via oro-tracheal or tracheostomy tube, 16 years of age or older Patient or substitute decision maker able to provide consent Exclusion Criteria: Expected withdrawal of treatments within 24 hours of screening Chronic respiratory failure already treated with mechanical ventilation before the injury Documented pre-existing neuromuscular diseases

Ages Eligible for Study
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Minimum Age: 16 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients with spinal cord injury<br>Patients treated with mechanical ventilation after a traumatic spine lesion with spinal cord injury | Other: Mechanical Ventilation<br>* Patients will be assessed and measurements will be taken during controlled ventilation (most likely <72 hours of ICU admission), during partially assisted ventilation, and until spontaneous unassisted breathing is reached.<br>|
| Patients with NO spinal cord injury<br>Patients treated with mechanical ventilation after a traumatic spine lesion with NO spinal cord injury | Other: Mechanical Ventilation<br>* Patients will be assessed and measurements will be taken during controlled ventilation (most likely <72 hours of ICU admission), during partially assisted ventilation, and until spontaneous unassisted breathing is reached.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Thickness and thickening fraction of the accessory muscles and their evolution over time during mechanical ventilation after spinal cord injury and spine trauma. | Patients with spinal cord injury will be compared to patients with spine trauma and no spinal cord injury, at baseline and at different time points. The evolution of the ultrasound thickness of the respiratory muscles will also be compared to the evolution of the thickness of the limb muscles (rectus femoris). Regarding the primary outcome, patients with spinal cord injury will be compared to patients with spinal trauma and no spinal cord injury at baseline and at different time points. The evolution of the ultrasound thickness of the respiratory muscles will also be compared to the evolution of the thickness of the limb muscles (rectus femoris). | Baseline measurements assessed ≤ 72 hours from admission and subsequent measurements assessed > 72 hours from intensive care unit admission, until spontaneous unassisted breathing is reached, up to 6 weeks from enrollment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Timing of activation and coordination of the diaphragm and of the different accessory muscles will be assessed using surface electromyography and monitored over time, after spinal cord injury and spine trauma. |  | > 72 hours after intensive care unit admission up to 6 weeks from enrollment | 
| Rib cage and abdomen displacement and their coordination will be recorded and monitored over time using respiratory inductive plethysmography, after spinal cord injury and spine trauma. | Measures to be assessed will be: phase angle, asynchronies and/or paradox of rib cage and abdomen, maximum compartmental amplitude/tidal volume ratio, rib cage/tidal volume ratio (relative contribution of the rib cage to the tidal volume). | > 72 hours after intensive care unit admission up to 6 weeks from enrollment | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Spinal cord injury, Trauma, Respiratory muscles, Mechanical ventilation, Acute respiratory failure, Diaphragm dysfunction