title: Effect of High-Frequency Oscillations on Cough Peak Flows Generated by Mechanical In-Exsufflation in Medically Stable Subjects With Amyotrophic Lateral Sclerosis.
abstract: BACKGROUND
  Mechanically assisted coughing with mechanical in-exsufflation (MI-E) is recommended for noninvasive management of respiratory secretions in amyotrophic lateral sclerosis (ALS). To improve the effectiveness of the technique, a new device combining MI-E with high-frequency oscillations (HFO) has been developed. This work aimed to assess the effect of HFO on the cough peak flow generated by MI-E in medically stable subjects with ALS.
  
  
  METHODS
  This was a prospective study that included subjects with ALS in a medically stable condition. Cough peak flow generated by MI-E was measured in 4 situations: without HFO, with HFO during insufflation, with HFO during exsufflation, and with HFO in both cycles. The parameters used were: insufflation pressure of +40 cm H2O, exsufflation pressure of -40 cm H2O, insufflation time 2 s, exsufflation time 3 s, amplitude of oscillations 10 cm H2O, and frequency of oscillations 15 Hz.
  
  
  RESULTS
  Forty-seven subjects with ALS were included: 66% males, 68.2 ± 9.2 y, 40% with bulbar onset, FVC = 1.7 ± 1.1 L, percent-of-predicted FVC = 54.4 ± 26.6%, cough peak flow = 3.8 ± 2.2 L/s, PImax = -39.4 ± 26.4 cm H2O, revised ALS scale = 28.5 ± 9.3, Norris bulbar subscore = 26.1 ± 10.4. No statistical differences were found in cough peak flow generated by MI-E in the 4 situations (without HFO = 4.0 ± 1.2 L/s, with insufflation HFO = 3.9 ± 1.2 L/s, with exsufflation HFO = 4.1 ± 1.2 L/s, with in-exsufflation HFO = 3.9 ± 1.1 L/s).
  
  
  CONCLUSIONS
  The addition of HFO to mechanically assisted coughing with MI-E does not have an effect on the cough peak flow of medically stable subjects with ALS.
authors.affiliation: Respiratory Care Unit, Respiratory Medicine Department, Hospital Clínico Universitario, Valencia, Spain. Research Group for Respiratory Problems in Neuromuscular Disease, Institute of Health Research INCLIVA, Valencia, Spain. jesus.sancho@uv.es.
authors.forename: Jesús
authors.initials: J
authors.lastname: Sancho
authors.affiliation: Respiratory Care Unit, Respiratory Medicine Department, Hospital Clínico Universitario, Valencia, Spain. Research Group for Respiratory Problems in Neuromuscular Disease, Institute of Health Research INCLIVA, Valencia, Spain.
authors.forename: Enric
authors.initials: E
authors.lastname: Bures
authors.affiliation: Respiratory Care Unit, Respiratory Medicine Department, Hospital Clínico Universitario, Valencia, Spain.
authors.forename: Saray
authors.initials: S
authors.lastname: de La Asunción
authors.affiliation: Respiratory Care Unit, Respiratory Medicine Department, Hospital Clínico Universitario, Valencia, Spain. Department of Physical Therapy, Universitat de Valencia, Valencia, Spain.
authors.forename: Emilio
authors.initials: E
authors.lastname: Servera
mesh_terms: D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000503:physiopathology / Q000628:therapy*; D003371:Cough / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D006612:High-Frequency Ventilation / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D007327:Insufflation / Q000295:instrumentation* / Q000379:methods; D008297:Male; D008875:Middle Aged; D010366:Peak Expiratory Flow Rate / Q000502:physiology*; D011446:Prospective Studies; D016896:Treatment Outcome
keywords: amyotrophic lateral sclerosis; cough-assist; neuromuscular disease; respiratory failure