Dräger Carina Instructions For Use Manual page 154

Principles of operation
Volume Guarantee
The expanded ventilation setting VG enables a vol-
ume guarantee in the SPN-CPAP/PS mode.
With VG every inspiratory effort of the patient on
PEEP level that meets the trigger criteria triggers a
volume-supported breath. By setting the trigger
level, the patient's inspiratory efforts are synchro-
nized. The time, number, and duration of volume-
supported breaths is determined by the patient's
spontaneous breathing. The pressure rise is deter-
mined by the Ramp setting.
The volume-supported breath is terminated as
soon as the inspiratory flow falls below a specific
proportion of the maximum inspiratory flow.
The proportion of the maximum inspiratory flow is
defined with the trigger criterion.
The volume-supported breath is also terminated as
soon as the duration of support exceeds a maxi-
mum inspiratory time Timax.
The set tidal volume of the supported breath is
reached via the automatically selected pressure
level of the volume support.
With volume support the support pressure automat-
ically adapts to the changes in lung conditions (re-
sistance and compliance) and the requirement for
spontaneous breathing of the patient.
154
Paw
PEEP
Inspiratory termination criterion
Flow
t
t
The maximum applied pressure is limited by the
Pmax set value. The difference between the alarm
limit Paw high and the set value Pmax is at least
5 mbar (5 cm H O).
2
Always set the alarm limits Paw high and pres-
sure limitation Pmax to limit a rise of the airway
pressure when compliance changes.
If the peak inspiratory pressure PIP reaches the
pressure limit Pmax, the desired target volume
cannot be applied. The device displays the mes-
sage VT not reached, Pmax !. Set Pmax to the
maximum allowable value. It is monitored from
breath to breath. To reach the target volume, the
peak inspiratory pressure PIP is adjusted by breath
(NIV: in steps of maximum 1 mbar, tube: maximum
3 mbar steps). The basis for the adjustment is the
tidal volume measured by the previous breaths.
Instructions for use Carina SW 3.2n