Dräger Carina Instructions For Use Manual page 148

Principles of operation
AutoFlow
The AutoFlow function is always activated in the
VC-SIMV and VC-AC ventilation modes.
PEEP
With AutoFlow, the inspiratory flow automatically
adapts to the changes in lung conditions (C, R) and
the requirement for spontaneous breathing of the
patient.
Always set the Paw high and pressure limitation
Pmax alarm limits to limit any rise in airway
pressure when the compliance changes.
Typically, the selected inspiratory time Ti is much
longer than the lung filling time. The peak inspira-
tory pressure PIP corresponds to the minimum
value calculated from the tidal volume VT and com-
pliance of the lungs.
The device automatically controls the inspiratory
flow so that there is no pressure peak caused by
the resistances of the tube and the airways. The
peak inspiratory pressure PIP changes as the com-
pliance changes, as is normal with constant-vol-
ume breaths.
148
Fast
pressure rise
Paw
PIP
Ti Te
1
RR
Flow
VT
Without spontaneous
breathing
Slow
pressure rise
With spontaneous
breathing
With AutoFlow these changes occur from breath to
breath (NIV: maximum 1 mbar steps; tube: maxi-
mum 3 mbar steps). The maximum peak inspira-
tory pressure PIP is determined by the pressure
limitation Pmax.
If the tidal volume VT is reached (inspiratory flow =
0) before the inspiratory time Ti has expired, the pa-
tient can inhale and exhale at the level of the peak
inspiratory pressure PIP during the remaining in-
spiratory time.
If the patient inhales or exhales during the manda-
tory inspiration, the peak inspiratory pressure PIP
does not change during this breath, only the inspir-
atory and expiratory flow adjust to the patient's re-
quirements. The individually applied tidal volume
VT may deviate from the set tidal volume VT in in-
dividual breaths, but a constant tidal volume VT is
applied over time.
Instructions for use Carina SW 3.2n
Paw
Pmax
t
t