Spinal Cord Stimulation to Shorten Ventilator Dependence in ARDS Patients

Study Overview
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Brief Summary
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This is an early phase, proof-of-concept clinical trial assessing the safety and feasibility of non-invasive spinal cord stimulation to prevent respiratory muscle atrophy in mechanically ventilated ARDS patients. The investigators will recruit 10 elective surgery patients (surgery cohort) and 10 ARDS patients (ARDS cohort) for this study. A non-invasive, alpha-prototype Restore Technology stimulator using hydrogel surface electrodes will be used to stimulate the spinal cord at the cervical or thoracic level.

Detailed Description
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Stimulation will be conducted in closed-loop fashion at the start of inspiratory cycle. Signal from a chest belt will be used to synchronize stimulation with ventilator and prevent interference with ventilator (see Protection of Human Subjects). Prior to treatment stimulation, mapping will be conducted at 1 Hz with electrodes placed in locations identified to be optimal in the surgery cohort. Assessment of evoked EMG responses from respiratory muscles will be conducted. Once this electrode configuration is confirmed as effective (capable of evoking EMG activity), stimulation with this configuration will be applied for treatment.

Official Title
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Transcutaneous Spinal Cord Stimulation to Improve Respiratory Function and Shorten Ventilator Dependence in Patients With ARDS

Conditions
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Respiratory Distress Syndrome

Intervention / Treatment
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* Device: Transcutaneous Biopac Electrical Stimulator


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or female 18-85 years; Intubated with confirmed diagnosis of ARDS (by Berlin Criteria: acute onset within one week of known insult, bilateral airspace opacities not fully explained by pleural effusions, atelectasis, and/or nodules, respiratory failure not explained by heart failure or fluid overload, PaO2/FiO2 ratio < 300); or identified as a patient admitted to the intensive care unit (ICU) after non-cardiac surgery; Able to provide informed consent or available next of kin able to provide informed consent; Have intact chest/lung, upper and lower extremity anatomy; The neuromuscular connections between the spinal cord, diaphragm, and intercostal muscles are intact; Enrollment of subject within 48 hours of intubation; Able to induce evoked response of diaphragm muscle by spinal cord TES. Exclusion Criteria: Phrenic nerve or diaphragm pacer; History of seizure disorder or on anti-epileptic medication for the treatment of seizures; Compromised skin in back (neck, upper and lower back); Pregnancy; Implanted devices: cardiac pacemakers, implanted defibrillators, implanted neurostimulators, phrenic nerve pacers; BMI greater than or equal to 35; Pharmacological paralysis/neuromuscular blockade*.

Ages Eligible for Study
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Minimum Age: 18 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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Design Details

Primary Purpose: Prevention
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: ARDS cohort<br>Patient diagnosed with ARDS. Treated daily for 60 minutes with transcutaneous cervical and/or thoracic spinal stimulation | Device: Transcutaneous Biopac Electrical Stimulator<br>* A transcutaneous electrical stimulator sends low levels of electrical current through surface hydrogel electrodes directly to the spinal cord to improve function.<br>|
| Experimental: Surgery Cohort (Active)<br>Patient undergoing inpatient non-cardiac surgery admitted to the intensive care unit (ICU) after surgery. Treated daily for 60 minutes with transcutaneous cervical and/or thoracic spinal stimulation | Device: Transcutaneous Biopac Electrical Stimulator<br>* A transcutaneous electrical stimulator sends low levels of electrical current through surface hydrogel electrodes directly to the spinal cord to improve function.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Recording of significant stimulation-induced adverse events (AE) | Although unlikely, we will record and monitor the number of stimulation-induced adverse events per case and per cohort. Our goal is to have an overall AE rate of less than 10% per cohort. | 1-48 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Recording of total ventilation time | The total time that patient is ventilated will be recorded to determine if stimulation reduces total intubation time | 1-48 months | 
| Measurement of diaphragm thickness | Evidence of maintenance of diaphragm muscle thickness (in mm) by ultrasound | 1-48 months | 
| Assessment of diaphragm and respiratory muscle EMG amplitudes | EMG amplitudes of diaphragm and other muscles involved in respiration (intercostals, trapezius, abdominal) will be measured at a couple time points throughout the study period to determine if stimulation can maintain muscle response. | 1-48 months | 
| Measurement of respiratory pressure | Peak Inspiratory and Expiratory pressure measurements (in mm Hg) will be recorded from ventilation units to determine if stimulation maintains or improves respiratory airway pressure. | 1-48 months | 
| Assessment of respiratory tidal volume | Respiratory Tidal Volume (voluntary and resting) will be recorded (in mL) to determine if stimulation assists in maintaining or improving lung capacity. | 1-48 months | 
| Measurement of ventilator weaning time | Measurements of ventilator weaning time will be recorded to determine if stimulation assists in decreasing the total time from complete intubation to complete extubation. | 1-48 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Respiratory Distress Syndrome