[Relationship between intermittent negative pressure level and tidal volume during biphasic cuirass ventilation in normal subjects].

The aim of this study was to investigate the effects of inspiratory negative pressure by biphasic cuirass ventilation on tidal volume and the relationship between pressure level and tidal volume in 15 normal subjects. We measured tidal volume during inspiratory negative pressures of -5, -10, -20 and -30 cm H2O. An inspiratory negative pressure of -30 cm H2O was necessary to increase tidal volume. We conclude that -30 cm H2O of biphasic cuirass ventilation significantly increases tidal volume in normal subjects.