呼吸生理和呼吸模式详解.ppt

* * * * 18 2 * 19 4 * 20 6 * 21 8 * 37 * 38 * * 27 17 Make sure to incorporate discussion on active exhalation valve in notes * 27 17 Make sure to incorporate discussion on active exhalation valve in notes * * * 34 34 34 34 34 18 Most ventilators currently on the market today terminate the inspiratory phase in Pressure Support Ventilation (PS) according to set termination criteria. This criteria is usually a percent of the peak flow for that particular breath. Clinicians have been limited in the past due to the inability to adjust this termination criteria. Expiratory Sensitivity (ESENS) defines the percentage of the projected peak inspiratory flow (VMAX) at which the ventilator terminates flow and thus cycles from inspiration to expiration during spontaneous breathing. A fixed PS termination criterion may potentially result in several clinical issues. If inspiratory flow terminates too early, it can lead to a decreased tidal volume, or increased inspiratory muscle load if the patients inspiratory effort persists after the ventilator has cycled flow off. Conversely, if inspiratory flow persists beyond patient effort which may happen when leaks are present, it can result in unnecessary expiratory work and patient/ventilator dysynchrony. * 34 34 34 34 34 18 Most ventilators currently on the market today terminate the inspiratory phase in Pressure Support Ventilation (PS) according to set termination criteria. This criteria is usually a percent of the peak flow for that particular breath. Clinicians have been limited in the past due to the inability to adjust this termination criteria. Expiratory Sensitivity (ESENS) defines the percentage of the projected peak inspiratory flow (VMAX) at which the ventilator terminates flow and thus cycles from inspiration to expiration during spontaneous breathing. A fixed PS termination criterion may potentially result in several clinical issues. If inspiratory flow terminates too early, it can lead to a decreased tidal