17
11.4
Ventilation modes
CMV ventilation mode
This mode is the only one available on 170 and is selected by default when the unit is turned on. It consist in the erogation of the medical
gas to the patient according to the parameters set with the adjustment knobs.
With this mode, the inspiratory and expiratory time ratio is constantly 1:2.
Air Mix/No Air Mix Selection
The lever placed on the front panel, allow to choose between two available FiO
2
levels.
If in NO AIR MIX mode, the ventilator delivers only the medical gas coming from the main medical gas supply to which the device is
connected. If the supply system delivers oxygen, the ventilator will deliver to the patient an oxygen concentration of 100%. Selecting the
AIR MIX mode, the ventilator draws 60% of gas from the medical gas supply and the remaining 40% from the environment where the
device used. In this case, if the main gas supply deliver oxygen, the concentration of this gas administered to the patient will be of 60%.
It is inappropriate to use the Air Mix mode in case of polluted environment. The device has a filter for incoming air subjected to periodic
replacement as specified in paragraph 12
11.5
Usage
The physician who directs rescue operation is responsible for the choice of the device to be used and for the clinical assessments needed
for the proper use of this device and for the choice of the proper ventilation parameters.
Patient circuits used for the ventilation must be chosen among those approved by the manufacturer. For ventilation of pediatric patients, a
pediatric patient valve must be used.
The residual pressure of the medical gas supply must be regularly checked to ensure enough autonomy. The achievement of the pressure
of the residual valve of the oxygen bottle, would result in the shutdown of the device and in the activation of an alarm signal.
The device provides alarms intended to limit risks of wrong adjustments or needed for a safe use of the product.
Alarms can be silenced by pressing the button identified by the symbol
placed on the frontal panel. The audio paused condition can be
identified by the illumination of the orange LEDs of the write “
AUDIO PAUSED”.
The audio pause function has no effect on lights and
alarms that are not active when the mute button is pressed.
For safety reasons, the alarms are not automatically disabled when the alarm condition no longer exist. To disable the audio paused
function and to terminate all active alarms, press the audio paused button for about 2 seconds.
The device has an internal 12V battery which provides an autonomy of about two hours when disconnected from the main power supply.
It’s also present a 9V backup battery needed for the operation of the alarms of the main battery charge status.
When the external power supply is active, the green led next to this symbol:
will light continuously. If connected to the external
power supply and the battery is not fully charged, the charging will automatically start and the white led next to the symbol:
will
light. Flashing of the white led next to the symbol:
identifies a particular condition that do not allow to charge the battery. (See par.
11.6).
The real pressure in the patient circuit is always shown on the manovacuometer placed on the front panel.
In standard conditions it is suggested to remove any implants, evaluate the need of bronchoaspiration, hyperextend the patient’s head
and, to ensure that the airways are clear, position the face mask over the mouth and nose checking the adherence of the soft part of the
mask on the patient’s face, in order to obtain a sealed system. It is important to verify that the mask is suitable for the patient; in the early
stages of the ventilation it is suggested to force the adhesion of the mask to the patient’s face.
The adjustment method of the volume minute knob (by steps), prevents changes in the set parameters due to accidental contacts.
Resistance of the airways due to obstructions or external cardiac massage does not cause a variation of the respiratory volume and
frequency. In case of reduction of the compliance, the ventilator will react with a rise of respiratory pressure at a constant volume.
During ventilation, constantly monitor the patient’s physiological response in order to verify if the set parameters are correct or to ensure
absence of complications.
Note:
The medical gas flow is not influenced by pressure. The ventilator does not monitor the oxygen concentration (mechanical mixing). Unless
otherwise specified the parameters are expressed in ATPD (Ambient, Temperature and Pressure Dry).
At the end of service, turn off the device by putting the lever on the “
O
” position, shut down the pneumatic supply and proceed with the
necessary maintenance activities.
11.6
Alarms and information signals
Each visual, acoustic or visual/acoustic signal is generated by conditions requiring attention and intervention by the operator.
The device is equipped with high priority alarms and has informations signals as described below.
Physiological high priority alarms
HIGH PRESSURE
Alarm specification
10 sequences of sound pulses spaced 2,5 seconds and dedicated led flashing two times per second
Reason of activation
The maximum pressure in the patient circuit has been exceeded.
This limit is activated at 60mbar if the frequency is set less than 20bpm and at 25 mbar if the
frequency is set higher than 20bpm
Possible causes of activation
1 – volume/minute set is to high
2 – the connection tube with the patient is crushed or obstructed
3 – Patient’s breathing resistances cause the activation of the alarm
Action to take
1 – decrease the volume/minute value
2 – free the tube and restore a safe condition
3 – Check that the ventilation parameters are adequate for the patient’s clinical conditions. Is
necessary to do more evaluation to ensure if intubation is needed. This means that the ventilation
must be carried out with other devices