Intrinsic (or auto-) positive end-expiratory pressure during spontaneous or assisted ventilation
The mechanisms generating intrinsic or auto-positive end-expiratory pressure (PEEP) during controlled mechanical ventilation in a relaxed patient also occur during spontaneous breathing or when the patient triggers the ventilator during an assisted mode [1, 2]. These include an increased time constant for passive exhalation of the respiratory system, a short expiratory time resulting from a relatively high respiratory rate and/or the presence of expiratory flow limitation. Whereas dynamic hyperinflation and intrinsic or auto-PEEP may have haemodynamic consequences, this is not frequently a major concern in spontaneously breathing patients or during assisted ventilation because the spontaneous inspiratory efforts result in a less positive or more negative mean intrathoracic pressure than during controlled mechanical ventilation. The main consequence of dynamic hyperinflation during spontaneous and assisted ventilation is the patient's increased effort to breathe and work of breathing [1, 2].
KeywordsChronic Obstructive Pulmonary Disease Assisted Ventilation Inspiratory Effort Control Mechanical Ventilation Dynamic Hyperinflation
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- 7.Ranieri MV, Giuliani R, Cinnella G, Pesce C, Brienza N, Ippolito E, Pomo V, Fiore T, Gottried S, Brienza A (1993) Physiologic effects of positive end-expiratory pressure in patients with chronic obstructive pulmonary disease during acute ventilatory failure and controlled mechanical ventilation. Am Rev Respir Dis 147:5–13PubMedCrossRefGoogle Scholar