Siemens Drager medical Carina, Инструкция по эксплуатации, Страница: 132 / 144

Description
132
Instructions for Use Carina SW 3.n
PC-BIPAP
Pressure Control – Biphasic Positive Airway
Pressure
This PC-BIPAP ventilation mode is pressure-con-
trolled or time-controlled ventilation during which
the patient can always breathe spontaneously.
PC-BIPAP is thus often described as a time-control-
led change between two pressure levels.
Controlled ventilation is achieved via a time-con-
trolled pressure change which corresponds to pres-
sure-controlled ventilation PC. However, the
constant option of spontaneous breathing allows
the transition from controlled breathing to inde-
pendent spontaneous breathing to take place
smoothly via the weaning phase, without requiring
any change in ventilation mode. For good adapta-
tion to the patient's spontaneous breathing behav-
iour, the switch from the expiratory pressure level to
the inspiratory pressure level is synchronised with
the patient's spontaneous breathing.
The frequency of changes is also kept constant dur-
ing synchronisation via a "trigger window" with
a fixed position in time.
Recent clinical experience shows that this good
adaptation to the spontaneous breathing of the
patient results in less sedation requirement and
thus a quicker return of the patient to complete
spontaneous breathing.
As with all pressure-controlled ventilation modes, a
non-fixed tidal volume VT is specified for the
patient. Tidal volume is primarily the result of the
pressure difference between the set points for
PEEP and P
insp
.
Changes in lung compliance and airways, as well
as active breathing by the patient can lead to
changes in tidal volume. This is a desired effect in
this ventilation mode.
With the knowledge that the tidal volume and there-
fore the minute volume are not constant, the alarm
limits for minute volume must be adjusted with care.
036
Flow
Paw
Ti
f
T=
PEEP
Pinsp
Trigger window
Ramp high Ramp low
t
t
1
Without spontane-
ous breathing
With spontaneous
breathing