Optimization of Non-invasive Diaphragm Activation Using Magnetic Phrenic Nerve Stimulation

NCT04176744 | Completed

• 1 other identifier: OPTISTIM_2019
• Study Type: interventional
• Target: 17
• Locations: 1 country
• Sites: 1

Brief Summary

The use of mechanical ventilation (MV) to replace spontaneous breathing has been associated with respiratory muscle dysfunction and lung injury from positive pressure. While using MV in an intensive care unit setting, the diaphragm is unloaded, potentially resulting in early development of diaphragmatic atrophy in as early as 18 hours of complete diaphragm inactivity. These changes in muscle properties result in a decrease in the force generating capability of the muscle, ultimately resulting in difficulty to restore spontaneous breathing and a subsequent prolonged weaning process or failure. A prolonged weaning period is associated with longer duration of MV, which may result in a cascade of further diaphragm dysfunction, weakness, and injury. Stimulation of the phrenic nerves to produce diaphragm contraction and activity is a possible mechanism to reduce MV related diaphragm dysfunction. Two promising studies have shown the potential of repetitive phrenic nerve stimulation on inducing diaphragm activity in human subjects with trains of pulses via both cervical and bilateral phrenic nerve stimulation. However, neither study provided optimal stimulation settings. As such, the primary purpose of this study is to investigate the optimal settings for noninvasive phrenic nerve stimulation to induce diaphragm contraction.

Conditions

Healthy

Outcome Measures

Primary Outcomes (5)

• Changes in airflow

  Flow will be recorded by a pneumotachometer and averaged over breaths.

  Continuously measured from 10 sec before until 10 sec after each stimulation. One stimulation lasts for approx. 1 sec.

• Changes in costal diaphragm activity

  Costal diaphragm activity will be continuously recorded via a wireless surface electromyography system.

  Continuously measured from 10 sec before until 10 sec after each stimulation. One stimulation lasts for approx. 1 sec.

• Changes in transdiaphragmatic pressure

  Transdiaphragmatic pressure changes, i.e. changes in esophageal and gastric pressures, will be measured by a pressure transducer connected to balloon-catheters.

  Continuously measured from 10 sec before until 10 sec after each stimulation. One stimulation lasts for approx. 1 sec.

• Changes in mouth pressure

  Mouth pressure will be continuously recorded using a differential pressure transducer.

  Continuously measured from 10 sec before until 10 sec after each stimulation. One stimulation lasts for approx. 1 sec.

• Changes in abdominal movements

  Abdominal movements will be assessed using the respiratory belt strain transducer.

  Continuously measured from 10 sec before until 10 sec after each stimulation. One stimulation lasts for approx. 1 sec.

Secondary Outcomes (4)

• Changes in extradiaphragmatic muscle activity

  Continuously measured from 10 sec before until 10 sec after each stimulation. One stimulation lasts for approx. 1 sec.

• Changes in head, shoulder and arm movements

  Continuously measured from 10 sec before until 10 sec after each stimulation. One stimulation lasts for approx. 1 sec.

• Changes in stress related parameters (heart rate, blood pressure, skin conductance)

  Continuously measured from 10 sec before until 10 sec after each stimulation. One stimulation lasts for approx. 1 sec.

• Perception of pain, paresthesia and distress

  Assessed 10 sec after each stimulation. One stimulation lasts for approx. 1 sec.

Study Arms (1)

Magnetic Phrenic Nerve Stimulation

EXPERIMENTAL

Each participant will be tested with 4 different stimulation setups (coils and stimulator) on 3 different days.

Other: Uni- and bilateral magnetic phrenic nerve stimulation

Interventions

Uni- and bilateral magnetic phrenic nerve stimulation OTHER

Uni- and bilateral magnetic phrenic nerve stimulation using different coils, stimulation patterns (frequency, intensity, number of pulses) and locations (neck, chest).

Magnetic Phrenic Nerve Stimulation

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Informed Consent as documented by signature
• Age: 18 - 35 years
• Non-smoking
• Healthy
• Able to communicate in English
• Normal lung function
• Normal Body mass index between 18.5 and 24.9 kg/m2
• Willingness to adhere to the study rules

You may not qualify if:

• Acute illness or chronic conditions affecting sleep or the performance of the respiratory, cardiovascular, neuromuscular, gastrointestinal or muscle system
• Women who are pregnant or breast feeding or have the intention to become pregnant during the course of the study
• Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, etc. of the participant
• Known or suspected non-compliance, drug or alcohol abuse
• Intake of medication affecting sleep or the performance of the respiratory, cardiovascular or neuromuscular system or gastrointestinal or muscle system
• Presence of cardiac pacemaker, implanted defibrillators or implanted neurostimulators
• Any metal or electronics inside of the body
• History of seizures or epilepsy
• Tattoos on the stimulation sites
• Previous enrolment into the current study

Sponsors & Collaborators

• Swiss Federal Institute of Technology: lead

Study Sites (1)

Exercise Physiology Lab, Institute of Human Movement Sciences and Sport, ETH Zurich

Zurich, Canton of Zurich, 8057, Switzerland

Location

Related Publications (1)

• Boyle KGPJM, Eichenberger PA, Schon P, Spengler CM. Inspiratory response and side-effects to rapid bilateral magnetic phrenic nerve stimulation using differently shaped coils: implications for stimulation-assisted mechanical ventilation. Respir Res. 2022 Dec 17;23(1):357. doi: 10.1186/s12931-022-02251-y.

  PMID: 36528761 DERIVED

Study Officials

• Christina M. Spengler, Prof.

  Exercise Physiology Lab, Institute of Human Movement Sciences and Sport, ETH Zurich

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Each participant enrolled in the study will be tested with different stimulation settings on three different days in a randomized order.

Study Record Dates

• First Submitted: November 19, 2019
• First Posted: November 25, 2019
• Study Start: December 9, 2019
• Primary Completion: July 15, 2020
• Study Completion: July 15, 2020
• Last Updated: August 12, 2020

Record last verified: 2019-12

Data Sharing

• IPD Sharing: Will not share

Locations

CH (1)