Instructions for use Zeus Infinity Empowered SW 2.n 447
Description
The trigger window is 25 % of set inspiratory time at
the upper pressure level (P
insp), but a maximum of
5 seconds or 25 % of T
e (Te = time of expiration).
However, on the PEEP level the maximum is
5 seconds. The trigger window can be switched off.
The good adaptation to the spontaneous breathing
of the patient results in a low sedation requirement
and thus a quicker return of the patient to spontane-
ous breathing. Recent clinical experience validates
this.
As with all pressure-controlled ventilation modes, a
non-fixed tidal volume VT is specified for the pa-
tient. The tidal volume is primarily the result of the
pressure difference between the set points for
PEEP and P
insp.
Modifications of lung compliance and the airways
as well as active counter-breathing of the patient
can modify the tidal volume. This is a desired effect
in this ventilation mode.
Knowing the non-constant tidal volume and thus
also the minute volume, an adequate setting of the
alarm limits for minute volume must be observed.
To set the necessary difference between the two
pressure levels, the display of the expiratory meas-
ured tidal volume VT
e is used. An increase in the
difference causes a higher pressure-controlled
ventilation breath.
As in synchronization with Vol. Ctrl. AutoFlow, the
time pattern is adjusted with the parameters of the
basic setting for respiratory rate RR and inspiration
time T
i. The lower pressure level is adjusted with
the parameter PEEP, the upper pressure level with
the parameter P
insp.
During synchronization of pressure-controlled ven-
tilation with Vol. Ctrl. AutoFlow, only the P
insp set-
ting needs to be modified while the time pattern is
maintained.
The steepness of the increase from the lower pres-
sure level to the upper pressure level is controlled
by the Slope setting. The effective time for the pres-
sure rise cannot become larger than the set inspi-
ration time T
i. Thus it is ensured that the upper
pressure level P
insp is achieved safely during inspi-
ration. The transition from controlled ventilation
over the weaning phase towards complete sponta-
neous breathing occurs via a gradual reduction of
inspiration pressure Pinsp and/or the respiratory
rate RR.
Volume Control AutoFlow
The volume mode Vol. Ctrl. AutoFlow guarantees
the application of an adjusted tidal volume by grad-
ual adaptation of the mechanical inspiration pres-
sure to lung conditions.
Spontaneous breathing is possible at any time. The
pressure patterns and flow patterns of the mechan-
ical inspiratory breaths correspond to those of pres-
sure-controlled ventilation.
The calculated inspiration pressure Pinsp adapts to
the current lung parameters (resistance R, compli-
ance Cdyn) and the spontaneous breathing re-
quirements of the patient. P
insp is always the mini-
mum ventilation pressure. This ventilation pressure
is required to fill the compliance of the lung with the
required tidal volume VT.
With modifications of lung compliance, the plateau
pressure changes accordingly, as is always the
case with volume-controlled ventilation forms. With
AutoFlow, the modifications occur at ventilation
pressure in up to 3 mbar steps from ventilation
breath to ventilation breath.
If the selected mechanical inspiration time T
i is
greater than or equal to the lung filling time, Pinsp
exactly equals plateau pressure. If the inspiration
time is shorter than the fill time of the lung, the in-
spiration flow at the end of the inspiration time does
not drop to zero. This can be detected from the flow
curve. In this case too, AutoFlow sets the minimum
P
insp under these conditions, which is, however,
above plateau pressure. Here the user must decide
whether an extension of inspiration time is useful in
order to further decrease the ventilation pressure.
If the set inspiration time Ti is longer than the fill
time of the lung, then the patient can breathe in and
out spontaneously within the remaining time at the
level of plateau pressure. Inspiration flow and expi-
ration flow adapt automatically to the needs of the
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