CareFusion AVEA - Demand Breaths; PSV (Pressure Support Ventilation)

76 Chapter 3: Ventilator Operation Operator's manual
L2786 Rev. M
The test breath sequence is initiated when any of the following occur:
• Entering the Mode (PRVC)
• Changing the set tidal volume while in PRVC
• Reaching the Volume Limit setting
• Delivered tidal volume > 1.5 times the set volume
• Flow termination of the test breath
• Exiting Standby
• Activation of any of the following alarms
High Peak Pressure Alarm
Low Peak Pressure Alarm
Low PEEP Alarm
Patient Circuit Disconnect Alarm
I-Time Limit
I:E Limit
Note:
If flow cycling is active during a PRVC or Vsync breath flow cycling of the breath can only occur if the target tidal
volume has been delivered. This allows for expiratory synchrony while assuring delivered tidal volume.
Note:
Demand Flow is active for all mandatory breaths. The maximum peak inspiratory pressure achievable by the
ventilator is limited by the high peak pressure alarm setting.
Demand Breaths
All demand breaths are patient-triggered, controlled by pressure, and flow or time cycled. Demand breaths can be either
pressure supported (PSV) or spontaneous. All demand breaths are accompanied by the yellow patient demand
indicator, which flashes in the upper left of the screen.
1. PSV (Pressure Support Ventilation)
A PSV breath is a demand breath in which the pressure level during inspiration is a preset PSV level plus PEEP.
The minimum pressure support level is PEEP + 2 cmH
2
O in adult and pediatric applications, independent of the set
PSV pressure level. In neonatal applications the minimum pressure support level is zero.
PSV breaths are:
• Controlled by pressure (preset PSV level + PEEP);
• Limited by pressure (preset PSV level + PEEP)
• Cycled by time (PSV T
max ) or flow (PSV Cycle).
Pressure Support is active when CPAP/PSV, SIMV or APRV/BiPhasic modes are selected