Abdominal Functional Electrical Stimulation in Tetraplegia

Abdominal Functional Electrical Stimulation to Augment Breathing in Tetraplegia

People with high spinal lesions are at risk of respiratory complications because they have partial or complete paralysis of breathing muscles. Previous work has shown that tetraplegic lung volumes can be increased by using abdominal FES during expiration. The technique is attractive because it is non-invasive, painless in tetraplegia and completely reversible. It may provide a treatment for augmenting the patient's breathing both in the acute presentation of spinal injury (when half of cervical injuries require ventilation) and in long term management of tetraplegia and high paraplegia. We propose a pilot study in a small group of subjects to see if the technique is feasible from both a clinical and engineering viewpoint. The aims of the study are: 1)To examine the effects of abdominal FES on lung mechanics and gas exchange in tetraplegic subjects. 2)To optimise the stimulation pattern and intensity via electronic stimulators and to design a trigger to allow the FES to follow the subject's own breathing cycle automatically.

Study Overview

• Status: Unknown
• Conditions: Spinal Cord Injury; Tetraplegia
• Intervention / Treatment: Device: Surface Functional Electrical Stimulation

Detailed Description

Patients with high spinal cord injury (SCI) usually have paralysed intercostal muscles and rely on diaphragm function alone for respiration. They have low tidal volumes and inadequate cough. These patients are vulnerable to respiratory complications in the immediate post-injury phase and remain at life-long risk of chest problems. Usual treatments include intensive physiotherapy and intermittent positive pressure ventilation to augment the patient's tidal volume and to help clear excess secretions.

Tidal volumes can also be increased by electrical stimulation of the surface of abdominal muscles during expiration. During stimulation the patient expires below functional residual capacity (the amount of air left after normal expiration). The natural elasticity of the chest wall then causes a recoil increase in the size of the next inspired breath. Functional electrical stimulation (FES) of the abdominal muscles is theoretically an attractive technique to augment respiration. It is non-invasive, it mimics natural physiological processes and tetraplegic patients cannot sense abdominal discomfort. There are potential applications in acute SCI patients to prevent the need for artificial ventilation and to aid ventilator weaning. The technique could also be used in chronically injured patients to augment ventilation.

Clinical staff at the Queen Elizabeth National Spinal Injuries Unit have collaborated extensively with engineering and bioengineering teams from Glasgow University and the University of Strathclyde in the use of FES in SCI. FES is already being used successfully in the Unit for paraplegic cycling and upper limb exercise in tetraplegia. We have performed abdominal FES on one SCI subject with complete diaphragm paralysis and produced a tidal volume of one hundred millilitres (McLean and Hunt, unpublished observation).

Before starting a large scale project it is important to confirm whether we can reliably reproduce at least some of the findings of Stanic et al. It would be very interesting if we could show any change in gas exchange as well as simply increasing tidal volume. Engineering issues include optimisation and programming of the FES stimulus. We propose a pilot study in QENSIU to establish whether the technique is of practical benefit to spinal cord injured patients.

• Study Type: Interventional
• Enrollment: 4
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Lanarkshire
    • Glasgow, Lanarkshire, United Kingdom, G51 4TF
      • Queen Elizabeth National Spinal Injuries Unit

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• cervical spinal cord injury

Exclusion Criteria:

• subject must not be ventilator-dependent

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Tidal Volume
Peak Expiratory Flow

Secondary Outcome Measures

Outcome Measure
Vital Capacity
Expired CO2 levels

Collaborators and Investigators

• Sponsor: South Glasgow University Hospitals NHS Trust
• Investigators: Principal Investigator: Alan N McLean, MRCP, Queen Elizabeth National Spinal Injuries Unit, Glasgow; Principal Investigator: Kenneth J Hunt, BSc, PhD, DSc, Department of Mechanical Engineering, University of Glasgow

Publications and helpful links

General Publications

• Stanic U, Kandare F, Jaeger R, Sorli J. Functional electrical stimulation of abdominal muscles to augment tidal volume in spinal cord injury. IEEE Trans Rehabil Eng. 2000 Mar;8(1):30-4. doi: 10.1109/86.830946.

Study record dates

Study Major Dates

• Study Start: June 1, 2002
• Study Completion: November 1, 2006

Study Registration Dates

• First Submitted: September 12, 2005
• First Submitted That Met QC Criteria: September 12, 2005
• First Posted (Estimate): September 20, 2005

Study Record Updates

• Last Update Posted (Estimate): November 28, 2006
• Last Update Submitted That Met QC Criteria: November 24, 2006
• Last Verified: November 1, 2006

More Information

Terms related to this study

• Keywords: functional electrical stimulation; spinal cord injury; quadriplegia; tetraplegia; abdominal stimulation
• Additional Relevant MeSH Terms: Central Nervous System Diseases; Nervous System Diseases; Neurologic Manifestations; Wounds and Injuries; Trauma, Nervous System; Spinal Cord Diseases; Paralysis; Spinal Cord Injuries; Quadriplegia
• Other Study ID Numbers: AbdomGlasgow