Technical Aspects of Patient-Ventilator Interactions
It has become increasingly clear that during patient-initiated volume-limited mechanical ventilatory assistance numerous factors can affect patient synchrony with the mechanical ventilator, the two most important being inspiratory trigger sensitivity and peak inspiratory flow. Decreasing inspiratory trigger sensitivity requires a greater system pressure change resulting in greater patient effort to initiate a mechanical breath [1, 2]. This greater effort reflects an increase in ventilatory drive, for there is good correlation between mouth occlusion pressure (P 0.1) and the pressure required to trigger a mechanical breath . In addition, Gurevitch and Gelmont  recently noted an increased delay in establishing system pressure during mechanical volume-limited breaths as trigger sensitivity is decreased.
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- 11.Hirsch CA, Kacmarek RM, Stanek K (1988) Mechanical ventilator demand-valve function with and without continuous positive airway pressure (CPAP) and pressure support (PS) (abstract). Respir Care 33:908Google Scholar
- 15.Kacmarek RM (1988) The role of pressure support ventilation in reducing work of breathing. Respir Care 33:99–120Google Scholar
- 16.Braschi A, Sala Gallini G, Rodi G et al. (1989) Relationship between sensitivity of the expiratory trigger and breathing pattern during pressure support ventilation (abstract). Am Rev Respir Dis 139:A361Google Scholar