Tecme NEUMOVENT, Техническое руководство

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TECHNICAL AND MAINTENANCE MANUAL
Graph VENTILATOR
Review : 04
Date: 09/05/06
12
Volume
VCV Assist/Control
Definition and Operative Proceeding:
It is a ventilatory mode with specific
regulation of the tidal volume. The inspiratory pressure is variable, and it depends on
the respiratory impedance to regulated volume.
During this mode, the ventilator works as a flow-controller where the selected flow
waveform is sustained during any lung compliance/resistance variation.
In this mode, the ventilator is time cycled, and the inspiratory flow is automatically
calculated and regulated. This means that for a given volume, the variations of the
inspiratory flow are obtained by means of the regulation of the inspiratory time. It also
explains why a rapid pressure drop without an inspiratory plateau marks the end of
inspiration, unless it is specifically regulated.
In the volume mode, the inspiratory flow can be changed by means of the flow
waveform control key.
The different flows are: descending ramp, constant, sine and ascending ramp. Each
of these flow waveforms also produces characteristic pressure and volume
waveforms.
This mode works with the
Assist/Control
characteristic, changing from a manner to
other according to the patient's demand (
inspiratory effort
).
If the patient’s inspiratory effort is reduced or an apnea episode is pr
esent, then, the
inspiration will be triggered by time (set machine frequency).
On the other hand, the patient's inspiratory effort could be enough to trigger the
ventilator and begin the inspiratory phase with he/she own breathing frequency and
according with the set trigger sensitivity.
Specific Controls for the VCV mode:
VT:
Regulation of gas volume propelled by the ventilator in each inspiration.
Flow Waveform:
To change the flow waveform.
Sigh:
With selection of sigh Vt; number (1,2 or 3 successively); events per hours (5,
10, 15, 20); insp. pressure limit.
Insp. Pause
: With time selection from 0.25 to 2.0 seconds.
Pressure
It comprises modes with specific regulation of the inspiratory pressure. It has two sub modes:
1) Pressure Controlled (PCV) Assist/Control
2) Pressure Support (PSV) and/or CPAP.
In both sub modes the ascending slope of the pressure can be varied with the
Rise Time
control.
PCV Assisted/controlled
Definition and Operative Proceeding:
In the Pressure-Controlled Ventilation mode
(PCV), the ventilator works as a positive pressure controller because the pressure
waveform remains the same when the patient’s compliance or resistance changes.
The switching from inspiration to expiration is normally regulated by time (inspiratory
cycling by time) or by pressure if the maximum safety pressure limit is reached. As in
all pressure-controlled modes, the ventilatory volume is variable and depends on the