Methods to Improve Expiratory Cough Flow and Lung Volume in Children With NMDs

Summary

Children with neuromuscular diseases (NMDs) and weak chest muscles suffer frequent chest infections, hospital admissions and reduced life expectancy. Physiotherapy is widely used but there is limited research data to support choice of therapy. The investigators will study the clinical value of the three most commonly used chest physiotherapy devices in children with NMD's by measuring lung function tests before and after each of the three treatments. This is a pilot study. The best device will be selected for a long term study of early physiotherapy intervention in children with NMDs.

The treatments that have been developed to break the cycle of decreasing lung volume and poor secretion clearance, in children with NMDs, are all based on the same logical but unproved theory of treatment:

1. The loss of lung volume is reversed by applying positive pressure to the lungs via a face mask - literally reinflating the lungs with pressure. The three devices the investigators will test all provide positive pressure assistance during the inspiratory phase.
2. The temporarily increased lung volume then allows higher expiratory flow rates which helps to clear secretions. The expiratory phase is assisted by manual chest compression or, in one device, helped by application of negative pressure during exhalation.

All three devices that the investigators wish to compare follow this two-step approach. The hypotheses behind our study are:

1. Treatments combining positive pressure inhalation with assisted coughing during exhalation, will produce measurable improvements in lung volume and expiratory cough flow rates when tested in children with NMDs.
2. One of the three devices tested will be superior to the others. This will provide research-based justification for a long term study of the value of early intervention in children with NMDs.

Conditions

• Neuromuscular Diseases

Interventions

DEVICE

Non-invasive bipap ventilator

The non-invasive bipap ventilator will be used in the following respiratory treatment: bipap assisted inspiratory breaths (BAIB). The patient will be encouraged to take deep breaths at least 1.5 times greater than resting tidal volume. The pressure assistance provided by the bipap starts at 10cm H2O. Patients already on bipap will use their home settings. Starting pressure is then increased as necessary to meet the maximal inspiratory goal volume in steps of 2 up to a maximum 20cm H2O. Once the ideal pressure of support levels are established, the child will perform 3 cycles of 5 deep breaths. After each cycle the patient will pause and perform huffing and assisted coughing. The patient will be suctioned as necessary.

DEVICE

Mechanical insufflator-exsufflator

A commercial mechanical insufflator-exsufflator will be used in the following treatment: Mechanical insufflation-exsufflation (MI-E). The pressure will be administered by a face mask. The optimal pressure for the test will start at 10 cm H2O and will in crease in steps of 5 to a maximum of 25 cm H2O. The insufflation phase will take 3 seconds followed by a 2 second exsufflation phase. Three cycles of treatment will be used. Between each cycle the subject will pause and perform huffing and assisted coughing. The patient will be suctioned as necessary.

DEVICE

High frequency percussive oscillator

A commercial high frequency percussive oscillator will be used in the following treatment: combined oscillation and nebulisation. Pressures will be delivered by a face mask. At higher oscillation frequencies it is usually necessary to support the cheeks. Pressure will be gradually be increased to accustom the child to a maximum of 25cm H2O. This standard maximal pressure will ideally be used for every child. A treatment cycle will consist of 3 minutes at a frequency of 2 Hz and pressure of 15cm H2O followed by 3 minutes of 4 Hz at 20cm H2O, then 3 minutes of 5 Hz at 25cm H2O. Throughout each cycle, the patient will receive nebulized saline through the machine. After each cycle the patient will pause and perform huffing and assisted coughing. The patient will be suctioned as necessary.

Sponsors & Collaborators

• University of British Columbia

  lead OTHER

Principal Investigators

• Mike Seear, MD · British Columbia's Children's Hospital

• Mike Seear, MD · BCCH

Study Design

Allocation

NA

Purpose

TREATMENT

Masking

SINGLE

Model

SINGLE_GROUP

Eligibility

Min Age

5 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2014-08-31

Primary Completion

2014-11-30

Completion

2015-02-28

Countries

• Canada

Study Locations