Original article
Lung Volume Recruitment Slows Pulmonary Function Decline in Duchenne Muscular Dystrophy

Presented to the American Thoracic Society, May 13-18, 2011, Denver, CO.
https://doi.org/10.1016/j.apmr.2012.02.024Get rights and content

Abstract

McKim DA, Katz SL, Barrowman N, Ni A, LeBlanc C. Lung volume recruitment slows pulmonary function decline in Duchenne muscular dystrophy.

Objective

To evaluate the long-term effect on measures of forced vital capacity (FVC) before and after the introduction of regular lung volume recruitment (LVR) maneuvers (breath-stacking) in individuals with Duchenne muscular dystrophy (DMD).

Design

Retrospective cohort study of pulmonary function data, including FVC, cough peak flow (CPF), maximum inspiratory pressure (MIP), and maximum expiratory pressure (MEP). Data were collected for 33 months prior to and 45 months after LVR introduction.

Setting

Ambulatory care in a tertiary level regional rehabilitation center in Canada.

Participants

All individuals (N=22) with DMD (mean age ± SD, 19.6±2.4y), who were prescribed LVR and reported adherence with therapy.

Interventions

Introduction of regular LVR (breath-stacking); 3 to 5 maximal lung inflations (maximum insufflation capacity [MIC]) using a hand-held resuscitation bag and mouthpiece, twice daily.

Main Outcome Measures

Measures included the rate of decline of FVC in percent-predicted, before and after the introduction of regular LVR. Changes in maximum pressures (MIP, MEP), MIC, and cough peak flows were also measured.

Results

At LVR initiation, FVC was 21.8±16.9 percent-predicted, and cough peak flows were <270L/min (144.8±106.9L/min). Annual decline of FVC was 4.7 percent-predicted a year before LVR and 0.5 percent-predicted a year after LVR initiation. The difference, 4.2 percent-predicted a year (95% confidence interval, 3.5–4.9; P<.000), represents an 89% improvement in the annual rate of FVC decline.

Conclusions

The rate of FVC decline in DMD patients improves dramatically with initiation of regular LVR.

Section snippets

Methods

All individuals with confirmed DMD at the Ottawa Hospital Rehabilitation Centre, for whom pulmonary function tests were available and who reported adherence with LVR, were included. Ethics approval was obtained from the Ottawa Hospital Research Ethics Board. LVR was administered by providing positive pressure, via tubing, and a mouthpiece, and was applied using a self-inflating resuscitation baga containing an inline 1-way valve.32 The number of breaths provided for LVR, per lung inflation, was

Results

A total of 22 individuals were included in this study. Demographic features are described in table 1. Not all measures were available for all patients at each assessment. At the time of LVR initiation, all participants had severe restrictive respiratory compromise (FVC, 21.8±16.9; percent-predicted, 1.0±0.7L) and CPF below 270L/min (144.8±106.9L/min), which is associated with decreased cough efficacy.17, 37, 38 All but 2 patients had a mechanical in-exsufflator available to them for use at home

Discussion

Risk of respiratory failure in neuromuscular diseases is directly related to lung capacity. Untreated, survival below a vital capacity of 1L in DMD is 8% at 5 years.31 Lung capacity is also strongly related to the ability to cough and clear airway secretions. It follows, therefore, that maintenance of lung capacity may have a significantly positive effect on mortality. To our knowledge, this is the first study to identify the long-term effects of LVR on the decline of lung function in

Conclusions

The rate of FVC decline improves dramatically with initiation of regular LVR in DMD patients.

Suppliers

  • a

    Lung Volume Recruitment Kit; Trudel Medical Marketing Ltd, 758 Third St, London, ON N5V 5J7, Canada.

  • b

    Medical Graphics Corp, 350 Oak Grove Parkway, St. Paul, MN 55127.

  • c

    Micro Medical Ltd, The Crescent, Jays Close, Bassingstoke RG22 4BS, UK.

  • d

    Mini-Wright Peak Flow Meter; Clement Clark International Ltd, Edinburgh Way, Harlow, Essex CM20 2TT, UK.

  • e

    R: A language and environment for statistical

Acknowledgment

We thank Christie O'Connell, BSc for her assistance in collecting and managing the data.

References (51)

  • K.A. Kleopa et al.

    Bipap improves survival and rate of pulmonary function decline in patients with ALS

    J Neurol Sci

    (1999)
  • S.C. Bourke et al.

    Effects of non-invasive ventilation on survival and quality of life in patients with amyotrophic lateral sclerosis: a randomised controlled trial

    Lancet Neurol

    (2006)
  • S.L. Katz

    Assessment of sleep-disordered breathing in pediatric neuromuscular diseases

    Pediatrics

    (2009)
  • A. Baydur et al.

    Long term noninvasive ventilation in the community for patients with musculoskeletal disorders: 46 year experience and review

    Thorax

    (2000)
  • Y. Khan et al.

    Sleep studies and supportive ventilatory treatment in patients with congenital muscle disorders

    Arch Dis Child

    (1996)
  • C.A. Hukins et al.

    Daytime predictors of sleep hypoventilation in Duchenne muscular dystrophy

    Am J Respir Crit Care Med

    (2000)
  • S. Katz et al.

    Outcome of noninvasive positive pressure ventilation in pediatric neuromuscular disease

    Arch Dis Child

    (2004)
  • H.B. Panitch

    The pathophysiology of respiratory impairment in pediatric neuromuscular diseases

    Pediatrics

    (2009)
  • E. Gomez-Merino et al.

    Duchenne muscular dystrophy: prolongation of life by noninvasive ventilation and mechanically assisted coughing

    Am J Phys Med Rehabil

    (2002)
  • M. Chatwin et al.

    Cough augmentation with mechanical insufflation/exsufflation in patients with neuromuscular weakness

    Eur Respir J

    (2003)
  • J.R. Bach

    Mechanical insufflation/exsufflation: has it come of age?A commentary

    Eur Respir J

    (2003)
  • R.M. Kravitz

    Airway clearance in Duchenne muscular dystrophy

    Pediatrics

    (2009 May)
  • D. McKim

    Keeping ventilated and ‘at-risk’ patients out of intensive care unit

    Can Resp J

    (2008)
  • H.B. Panitch

    Airway clearance in children with neuromuscular weakness

    Curr Opin Pediatr

    (2006)
  • J.R. Bach et al.

    Airway secretion clearance by mechanical exsufflation for post-poliomyelitis ventilator-assisted individuals

    Arch Phys Med Rehabil

    (1993)
  • Cited by (0)

    No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organization with which the authors are associated.

    Reprints are not available from the author.

    In-press corrected proof published online on Apr 21, 2012, at www.archives-pmr.org.

    View full text