title: Diaphragm Pacing as a Rehabilitative Tool for Patients With Pompe Disease Who Are Ventilator-Dependent: Case Series.
abstract: OBJECTIVE
  Pompe disease is an inherited disorder notable for severe, progressive ventilatory compromise. Although ventilatory failure has been attributed to myofiber dysfunction secondary to diaphragmatic glycogen accumulation, neural involvement of the phrenic motor system is also a prominent feature. Direct diaphragm pacing supplements respiratory function in other disorders of the phrenic motor system. Accordingly, it is hypothesized that augmented neuromuscular activity via diaphragm pacing would promote weaning from mechanical ventilation in patients with Pompe disease who are unresponsive to conventional, muscle-directed treatments.
  
  
  METHODS
  Three patients with Pompe disease developed diaphragm paresis that resulted in chronic mechanical ventilation dependence. After preoperative inspiratory muscle strengthening exercises failed to improve function, fine-wire pacing electrodes were laparoscopically implanted into the diaphragm. Diaphragm conditioning was initiated the first postoperative week and consisted of gradual increases in stimulation parameters, lengthening of stimulation sessions, and ventilator weaning. Ventilation and intramuscular electromyographic activity were recorded periodically during conditioning to quantify diaphragm neuromuscular function.
  
  
  RESULTS
  During paced breathing without mechanical ventilation, tidal volumes increased, and 2 patients were weaned from daytime ventilator dependence within the first 3 months of pacing, which has been sustained over the long-term. A third patient reduced reliance on daytime ventilation, but weaning was delayed by malacia of the large airways. In all patients, pacing appeared to facilitate spontaneous phrenic motor unit activity during independent breathing without ventilator or pacer support.
  
  
  CONCLUSIONS
  The findings are consistent with the view that diaphragm pacing has potential rehabilitative value to reduce reliance on mechanical ventilation in people with Pompe disease, but further study is needed. Diaphragm pacing represents a paradigm shift in the management of respiratory insufficiency for Pompe disease that warrants further controlled examination.
authors.affiliation: B.K. Smith, PT, PhD, Department of Physical Therapy, University of Florida, PO Box 100154, Gainesville, FL 32610 (USA), and Department of Pediatrics, University of Florida. bksmith@phhp.ufl.edu.
authors.forename: Barbara K
authors.initials: BK
authors.lastname: Smith
authors.affiliation: D.D. Fuller, PhD, Department of Physical Therapy, University of Florida.
authors.forename: David D
authors.initials: DD
authors.lastname: Fuller
authors.affiliation: A.D. Martin, PT, PhD, Department of Physical Therapy, University of Florida.
authors.forename: A Daniel
authors.initials: AD
authors.lastname: Martin
authors.affiliation: L. Lottenberg, MD, Department of Surgery, College of Medicine, Florida Atlantic University, Boca Raton, Florida.
authors.forename: Lawrence
authors.initials: L
authors.lastname: Lottenberg
authors.affiliation: S. Islam, MD, MPH, Department of Pediatrics, University of Florida, and Department of Surgery, University of Florida.
authors.forename: Saleem
authors.initials: S
authors.lastname: Islam
authors.affiliation: L.A. Lawson, MS, ARNP, Department of Pediatrics, University of Florida.
authors.forename: Lee Ann
authors.initials: LA
authors.lastname: Lawson
authors.affiliation: R.P. Onders, MD, Department of Surgery, Case Western Reserve University, Cleveland, Ohio.
authors.forename: Raymond P
authors.initials: RP
authors.lastname: Onders
authors.affiliation: B.J. Byrne, MD, PhD, Department of Pediatrics, University of Florida.
authors.forename: Barry J
authors.initials: BJ
authors.lastname: Byrne
mesh_terms: D002675:Child, Preschool; D003964:Diaphragm / Q000503:physiopathology*; D004599:Electric Stimulation Therapy; D004567:Electrodes, Implanted; D004576:Electromyography; D006009:Glycogen Storage Disease Type II / Q000150:complications / Q000503:physiopathology* / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration; D012123:Pulmonary Ventilation; D012119:Respiration; D012131:Respiratory Insufficiency / Q000209:etiology / Q000503:physiopathology / Q000534:rehabilitation*; D015300:Ventilator Weaning