Comparative effects of two ventilatory modes on speech in tracheostomized patients with neuromuscular disease

Am J Respir Crit Care Med. 2003 Jan 15;167(2):114-9. doi: 10.1164/rccm.200201-026OC. Epub 2002 Oct 4.


Many patients with respiratory failure related to neuromuscular disease receive chronic invasive ventilation through a tracheostomy. Improving quality of life, of which speech is an important component, is a major goal in these patients. We compared the effects on breathing and speech production of assist-control ventilation (ACV) and bilevel positive-pressure ventilation (BPPV) in nine patients with neuromuscular disease. Ventilator-delivered flow was measured using a pneumotachograph, and respiratory rate, inspiratory time, and ventilator-delivered volume were measured on this flow signal. Gas exchange was assessed using oxygen saturation and end-tidal carbon dioxide measurement. Microphone speech recordings were subjected to quantitative analysis. At rest, ventilatory parameters were similar with both modes. Speech induced an increase in inspiratory time during BPPV, with a greater increase in the volume released by the ventilator during speech as compared with ACV (172 +/- 194 versus 26 +/- 31 ml). Consequently, speech duration was longer during inspiration with BPPV. Moreover, BPPV allowed speech production to extend into expiration, and three patients could speak continuously during several respiratory cycles while receiving BPPV. Blood gas exchange was not modified by speech with BPPV or ACV. This study shows that BPPV provides better speech duration than ACV with no detectable short-term deleterious effects.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Analysis of Variance
  • Female
  • Humans
  • Intubation, Intratracheal
  • Male
  • Middle Aged
  • Neuromuscular Diseases / complications*
  • Neuromuscular Diseases / diagnosis
  • Positive-Pressure Respiration / adverse effects
  • Positive-Pressure Respiration / methods
  • Probability
  • Prognosis
  • Prospective Studies
  • Pulmonary Gas Exchange
  • Respiration, Artificial / adverse effects
  • Respiration, Artificial / methods*
  • Respiratory Insufficiency / etiology
  • Respiratory Insufficiency / therapy*
  • Respiratory Mechanics
  • Risk Assessment
  • Sampling Studies
  • Severity of Illness Index
  • Speech / physiology*
  • Speech Intelligibility
  • Speech Production Measurement
  • Tracheotomy / adverse effects
  • Tracheotomy / methods