Breas Vivo 45 LS User Manual page 72

5.4.4.1 Pressure Support Ventilation (PSV)
In the PSV mode, the patient's spontaneous breathing is assisted by the ventilator. The
patient controls the start of inspiration through the inspiratory trigger and the start of
exhalation by the expiratory trigger.
The set pressure is used as a target pressure, if the flow is decreased to the expiratory
trigger level before the set pressure is reached, the expiration starts.
When an inspiration is started, either when the patient triggers a breath, or when the
backup rate setting initiates an inspiration in case of a prolonged Apnea, the ventilator
delivers a flow up to a certain preset pressure limit. In case of a patient initiated breath,
the patient continues the breath for as long as they wish and cycle off when a percentage
drop in peak inspiratory flow (expiratory trigger) has been reached.
Spontaneous breaths stop and an exhalation starts in three cases:
• The inspiration flow has dropped to the value set for expiratory trigger.
• The inspiration time is longer than the limit for maximal inspiration time or when
inspiration time reaches 3 seconds.
• The limit for the high-pressure alarm is reached.
5.4.4.2 Pressure Support Ventilation with Target Volume (PSV+ TgV)
The PSV+TgV mode acts as the PSV mode but with an added regulation of the pres-
sure. Target volume is a feature that automatically adapts the pressure to make sure that
the Vivo 45 LS delivers the desired set target volume to the patient. The delivered vol-
ume is compared to the set target volume on a breath by breath basis. The delivered
pressure for the next breath will be increased or decreased depending on the difference
between the delivered volume and the set target volume. Automatic pressure adjust-
ments will be made in between two adjustable limits (min IPAP and max IPAP) in order
to deliver the optimal support to the patient
See 5.5.17 Target Volume, page 86 for more information about Target Volume.
5.4.4.3 Pressure Controlled Ventilation (PCV)
In the PCV mode the ventilation is controlled by the Vivo 45 LS. This is done at the
preset pressure, breath rate, inspiratory time, and rise time settings set by the operator.
The patient also has the possibility to start a breath through the Inspiratory Trigger.
This patient triggered breath will be delivered with the inspiratory time, rise time and
pressure setting set by the operator.
The inspiration stops and an expiration starts in two cases:
• The inspiration time expires.
• The limit for the high pressure alarm is reached.
72 How to Use the Vivo 45 LS
User manual
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