3. Improving Patient-Ventilator Synchrony â Smartâ Rise Time 1. ïŻ WOB, specifically insp. muscle effort , associated with inappropriate flow rate during PSV or PCV. 2. less problems associated with flow and achievement of set pressure in response to changes in lung condition as SRT is self- adjusting due to a Pressure Memory Algorithm
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6. Patient with ï Airway Resistance Gas flow is greatest where resistance is low, hence overinflation of normal lung units. ïŻ V/Q PvCO 2 = 46 mmHg PvO 2 = 40 mmHg PaO 2 = 70 mmHg PaCO 2 = 45 mmHg PaCO 2 = 43 mmHg PaO2 = 60 mmHg
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10. Expiratory W.O.B. and auto-PEEP in the COPD Patient MJ Tobin. NEJM 2001; 344: 1986-96.
11. PS and WOB during Expiration PRESSURE Esens allows the clinician to adjust the ventilatorâs onset of expiration to match the patientâs breathing pattern. FLOW PS overshoots target Esens fixed 25% Esens adjusted to 50% Normal Problem resolved 0 100 0 15
25 25 25 25 25 Once the patient has triggered the ventilator into inspiration, the next concern regarding patient comfort and coordination between the ventilator and the patient is flow acceleration percent.
30 30 30 30 30 Next we will talk about preventing pressure overshoot and and sustaining the breath as it relates to the active exhalation valve.
33 33 33 33 33 In the spontaneously breathing patient in PS the next issue is transition into exhalation.
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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 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 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.