title: Effects of negative pressure assisted ventilation on dyspnoeic sensation and breathing pattern.
abstract: Although negative pressure assisted ventilation with an assist-control mode may have a potential therapeutic role in the treatment of severe dyspnoea, the effects of negative pressure assisted ventilation with the assist-control mode on dyspnoea and breathing patterns have not been examined. We examined the effects of negative pressure assisted ventilation with the assist-control mode on dyspnoea and breathing patterns produced by a combination of resistive loading and hypercapnia in nine healthy subjects breathing spontaneously. Subjects were asked to rate their sensation of respiratory discomfort using a visual analogue scale. Negative pressure assisted ventilation caused a significant reduction in sensation of respiratory discomfort from a visual analogue scale score of 74 (55-91) (median (range)) before negative pressure assisted ventilation to 34 (15-53) during negative pressure assisted ventilation (p<0.01). During negative pressure assisted ventilation, there were significant changes in breathing patterns characterized by an increase in tidal volume and a decrease in respiratory frequency, while neither minute ventilation nor end-tidal carbon dioxide tension changed. Our results indicate that negative pressure assisted ventilation with the assist-control mode is effective in relief of dyspnoea and that negative pressure assisted ventilation influences the control of breathing to minimize respiratory discomfort.
authors.affiliation: Dept of Anaesthesiology, School of Medicine, Chiba University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nishino
authors.forename: S
authors.initials: S
authors.lastname: Isono
authors.forename: T
authors.initials: T
authors.lastname: Ide
mesh_terms: D000328:Adult; D004417:Dyspnea / Q000503:physiopathology*; D006801:Humans; D008875:Middle Aged; D012119:Respiration; D012121:Respiration, Artificial / Q000379:methods*; D015656:Respiratory Mechanics; D012677:Sensation; D015919:Ventilators, Negative-Pressure