Diaphragm Pacing in Individuals With Spinal Cord Injuries

Diaphragm Stimulation After Human Spinal Cord Injury: Effects on Respiratory Neural Drive and Function

This project will evaluate the effects of intramuscular diaphragm stimulation (pacing) and test the hypothesis that diaphragm pacing enhances neuromuscular diaphragm activation and respiratory function in adults with cervical spinal cord injuries (C-SCIs). The investigators will test the hypothesis by recording activity of the diaphragm from intramuscular pacing electrodes and conduct respiratory assessments in adults with intramuscular diaphragm pacing electrodes following acute, traumatic C-SCIs.

Study Overview

• Status: Completed
• Conditions: Cervical Spinal Cord Injury
• Intervention / Treatment: Device: Diaphragm Pacing

Detailed Description

Respiratory dysfunction is a leading cause of death in individuals with spinal cord injuries (SCIs). Nearly one-quarter of all SCI cases involve injury to the upper spinal cord segments which impairs neural activation of the diaphragm muscle and compromises breathing. Although mechanical ventilation can be life-saving after cervical SCI (C-SCI), it also triggers rapid and profound diaphragm muscle atrophy, thereby complicating (or even preventing) ventilator weaning. Intramuscular diaphragm stimulation, or diaphragm pacing, was developed to replace long-term ventilator support and is now used acutely post C-SCI (<4 months following injury) to promote ventilator weaning. This study will assess the effects of diaphragm stimulation on respiratory neural drive and breathing function in individuals with acute, traumatic C-SCI. Recording from these surgically implanted electrodes allows comparisons of electromyogram (EMG) recordings, in association with respiratory assessments, before and after short periods of diaphragm pacing to isolate the unique contribution of diaphragm pacing on neuromuscular diaphragm activation.

• Study Type: Observational
• Enrollment (Actual): 6

Contacts and Locations

Study Locations

• United States
  • Florida
    • Jacksonville, Florida, United States, 32008
      • UF Health - Jacksonville

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 73 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients with acute, traumatic C-SCIs, scheduled to receive intramuscular diaphragm pacing OR who have recently received a diaphragm pacer (within past 5-days) will be recruited from UF Health Shands Jacksonville, a Level-1 trauma hospital serving North Florida.

Description

Inclusion Criteria:

• Acute, traumatic cervical spinal cord injuries (C-SCIs), classified according to the American Spinal Injury Association (ASIA) Impairment Scale (AIS) as A-C
• Scheduled to undergo implantation of a diaphragm pacer, or who have recently received (in past 5-days) implantation of intramuscular diaphragm pacing electrodes due to severe respiratory impairments and dependence on mechanical ventilation

Exclusion Criteria:

• Progressive neuromuscular diseases such as multiple sclerosis and myasthenia gravis
• History of neurologic injuries such as stroke or prior SCI
• Chest wall injuries or deformities likely to influence breathing
• Pregnancy
• Cognitive impairments limiting study participation

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Only
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Cervical SCI; Participants with acute, traumatic cervical spinal cord injuries (C-SCIs), classified according to the American Spinal Injury Association (ASIA) Impairment Scale (AIS) as A-C (complete SCI (A); motor complete SCI (B); motor incomplete with minimal motor function (C)), affecting C1-C6 spinal cord segments, and who have been scheduled to undergo implantation of a diaphragm pacer, or who have recently received (in past 5-days) implantation of intramuscular diaphragm pacing electrodes due to severe respiratory impairments and dependence on mechanical ventilation.

Device: Diaphragm Pacing; Intramuscular stimulation of the diaphragm, or diaphragm "pacing' is achieved by laparoscopic placement of stimulation wires into each hemidiaphragm. Phrenic motor points on the diaphragm are mapped to optimize electrode placement. The electrodes are threaded into the diaphragm muscle and wire leads are externalized and attached to a stimulation controller.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Electromyogram (EMG)	Neuromuscular activation of the diaphragm will be assessed by recording diaphragm EMGs from the surgically-implanted intramuscular stimulating electrodes. This approach will allow for comparisons of EMG recordings across time. EMGs will be recorded during non-stimulated respiration (diaphragm pacer turned off) and simultaneously with assessments of respiratory function.	Baseline up to 24 hours
Change in Maximal Inspiratory Pressure (MIP)	The Maximum Inspiratory Pressure (MIP) is measured by a device that applies an inspiratory load which provides a resistance. The MIP will be measured in cmH20 and assesses diaphragm strength. MIP will be recorded will be recorded during non-stimulated respiration (diaphragm pacer turned off).	Baseline up to 24 hours
Change in Tidal Volume	The measurement of Tidal Volume is performed through a simple spirometry and is measured in liters. Tidal Volume will be recorded during non-stimulated respiration (diaphragm pacer turned off).	Baseline up to 24 hours

Collaborators and Investigators

• Sponsor: University of Florida
• Collaborators: National Institutes of Health (NIH)
• Investigators: Principal Investigator: Emily Fox, PT, PhD, University of Florida

Study record dates

Study Major Dates

• Study Start (Actual): January 10, 2020
• Primary Completion (Actual): August 20, 2022
• Study Completion (Actual): August 20, 2022

Study Registration Dates

• First Submitted: November 1, 2019
• First Submitted That Met QC Criteria: November 25, 2019
• First Posted (Actual): November 27, 2019

Study Record Updates

• Last Update Posted (Actual): October 30, 2023
• Last Update Submitted That Met QC Criteria: October 27, 2023
• Last Verified: October 1, 2022

More Information

Terms related to this study

• Keywords: SCI; diaphragm pacing; respiratory impairment; diaphragm stimulation
• Additional Relevant MeSH Terms: Central Nervous System Diseases; Nervous System Diseases; Trauma, Nervous System; Spinal Cord Diseases; Wounds and Injuries; Spinal Cord Injuries
• Other Study ID Numbers: IRB201902285; 1OT2OD023854 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No